WO2017163572A1 - Playback apparatus and playback method - Google Patents

Playback apparatus and playback method Download PDF

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Publication number
WO2017163572A1
WO2017163572A1 PCT/JP2017/001957 JP2017001957W WO2017163572A1 WO 2017163572 A1 WO2017163572 A1 WO 2017163572A1 JP 2017001957 W JP2017001957 W JP 2017001957W WO 2017163572 A1 WO2017163572 A1 WO 2017163572A1
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WIPO (PCT)
Prior art keywords
sound
signal
unsteady
collected
playback
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PCT/JP2017/001957
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French (fr)
Japanese (ja)
Inventor
正也 小西
村田　寿子
優美 藤井
敬洋 下条
敬介 小田
Original Assignee
株式会社Ｊｖｃケンウッド
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Publication of WO2017163572A1 publication Critical patent/WO2017163572A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/10—Earpieces; Attachments therefor ; Earphones; Monophonic headphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
    • H04R1/40—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04S—STEREOPHONIC SYSTEMS 
    • H04S1/00—Two-channel systems

Definitions

  • the present invention relates to a playback device and a playback method.
  • a portable music player such as a digital audio player can listen to music while jogging outdoors.
  • inconvenience may occur if surrounding sounds such as announcement sounds cannot be heard.
  • Patent Document 1 discloses a portable device that uses headphones to deliver ambient sounds to the user's ears while listening to music with headphones.
  • ambient sounds are collected by a microphone.
  • the portable device compares the sound input from the microphone with the data stored in the database, and determines whether the sound is to be output. When it is determined that the input sound is to be output, the mode is shifted to the alert mode and is mixed with the output sound.
  • Patent Document 2 discloses a sound reproducing device having an earphone and a microphone.
  • the earphone emits a sound signal into the ear.
  • the microphone picks up the sound outside the ear.
  • the sound reproducing device extracts the sound emitted from the moving body using a filter that passes through the band of the sound emitted from the moving body such as an automobile or a motorcycle.
  • the sound reproducing device calculates a time gradient of the collected sound signal and determines whether or not the moving body is approaching. When the moving body is approaching, the sound reproducing device reduces the level of the sound signal supplied to the earphone. By doing in this way, the user can know that the moving body is approaching.
  • Patent Document 3 discloses a headphone device that localizes music output from a music player outside the listener's head and localizes a ringing tone called from a mobile phone.
  • the level of the sound signal is lowered when the moving body is approaching.
  • it can be heard that surrounding sounds and music are sounding at the ears. For this reason, it may be difficult to hear ambient sounds due to the masking effect.
  • earphones or headphones with high sound insulation are used, the sound emitted from the moving body is blocked. Even if the sound insulation is lowered so that the ambient sound can be heard, the ambient sound becomes difficult to hear if the volume of the music being played is high. Therefore, in the apparatus of Patent Document 2, it may be difficult for the user to listen to surrounding sounds. Similarly, in the apparatus of Patent Document 3, it may be difficult for the user to listen to surrounding sounds.
  • earphones with low sound insulation are used, sound leakage may occur when the playback volume is increased.
  • the present embodiment has been made in view of the above points, and an object thereof is to provide a playback device and a playback method that allow a user to appropriately listen to surrounding sounds.
  • a playback apparatus includes a playback unit that outputs a playback signal for playing back playback sound, and an output unit that includes left and right output units that output sound toward the left and right ears of the user, respectively.
  • the reproduction method includes a step of outputting a reproduction signal for reproducing reproduction sound, and a step of collecting ambient sound using one or more microphones to obtain a sound collection signal.
  • FIG. 1 is a block diagram showing a configuration of a playback device according to a first embodiment. It is a figure which shows typically the structure of the earphone used for a reproducing
  • FIG. 6 is a flowchart showing a process for detecting an unsteady sound in the reproduction method according to the present embodiment. It is a figure for demonstrating the sound source direction of an unsteady sound. It is a figure which shows typically the change of the sound collection signal at the time of normal time and unsteady sound detection. It is a figure which shows typically the signal at the time of normal time and unsteady sound detection. It is a flowchart which shows the process which specifies the sound source direction of an unsteady sound. It is a flowchart which shows the process which switches a filter according to a sound source direction. It is a conceptual diagram which shows the structure which produces
  • the playback device includes a playback unit that plays back playback sound and an output unit such as an earphone or headphones.
  • the playback unit is typically a portable music player or a portable video player such as a digital audio player, a smartphone, or a tablet terminal, and records a playback sound in advance in an internal memory or cloud.
  • the playback sound is a sound at the time of music or video playback.
  • the music player With the user wearing earphones or headphones, the music player outputs a playback signal to the output unit.
  • a portable playback device By using a portable playback device, a user can listen to music outdoors.
  • FIG. 1 is a block diagram of a control configuration of the playback apparatus 100 according to the first embodiment.
  • FIG. 2 is a diagram schematically showing the configuration of the earphone 105 and the directional microphone 101 used in the playback apparatus 100.
  • the playback apparatus 100 includes a directional microphone 101, an out-of-head localization processing unit 102, a music player 103, a synthesis unit 104, and an earphone 105.
  • the music player 103 is, for example, a digital audio player or a smartphone application, and plays prerecorded music.
  • the music player 103 outputs a reproduction signal based on the reproduced music to the synthesis unit 104.
  • the reproduction signal is a stereo input signal. That is, the reproduction signal includes an Lch stereo input signal input to the left output unit 105L of the earphone 105 and an Rch stereo input signal input to the right output unit 105R.
  • the Lch stereo input signal is output from the left output unit 105L to the user's left ear, and the Rch stereo input signal is output from the right output unit 105R to the user's right ear.
  • the playback sound is music
  • the music player 103 is used.
  • an application that can play a moving image can be used instead of the music player 103.
  • the directional microphone 101 is a microphone that collects sounds around the user.
  • the directional microphone 101 outputs a collected sound signal based on the ambient sound to the out-of-head localization processing unit 102.
  • the directional microphone 101 collects sound generated behind the user. That is, the directional microphone 101 is a microphone having directivity behind the user.
  • the out-of-head localization processing unit 102 performs out-of-head localization processing on the collected sound signal from the directional microphone 101. Specifically, the out-of-head localization processing unit 102 convolves a filter with the collected sound signal. By doing so, the out-of-head localization processing unit 102 generates a sound collection signal subjected to localization processing. The out-of-head localization processing unit 102 outputs the collected sound signal subjected to the localization process to the synthesis unit 104. The out-of-head localization processing unit 102 performs out-of-head localization processing by convolving transfer characteristics such as a head-related transfer function HRTF (Head Related Transfer Function).
  • HRTF Head-related Transfer Function
  • an Lch filter corresponding to the transfer characteristic for the left ear and an Rch filter corresponding to the transfer characteristic for the right ear are set.
  • the out-of-head localization processing unit 102 convolves an Lch filter with the collected sound signal from the directional microphone 101 to generate a localized Lch collected sound signal.
  • the out-of-head localization processing unit 102 convolves an Rch filter with the collected sound signal from the directional microphone 101 to generate a localized Rch collected sound signal.
  • the filter used for the out-of-head localization processing unit 102 will be described later.
  • the synthesizing unit 104 is a mixer that synthesizes the localized sound collection signal and the reproduction signal. Specifically, the synthesis unit 104 generates a synthesized signal by adjusting and synthesizing the volume balance between the collected sound signal and the reproduction signal. The combining unit 104 outputs the combined signal to the earphone 105.
  • the synthesis unit 104 multiplies the sound collection signal and the reproduction signal by a coefficient corresponding to the volume balance. Then, the synthesis unit 104 generates a synthesized signal by adding the collected sound signal multiplied by the coefficient and the reproduction signal.
  • the synthesizing unit 104 performs synthesis processing on each of the Lch signal and the Rch signal. That is, the combining unit 104 adds the Lch sound pickup signal and the Lch reproduction signal to generate an Lch combined signal. Similarly, the synthesis unit 104 adds the Rch reproduction signal and the Rch sound collection signal to generate an Rch synthesis signal.
  • the combining unit 104 outputs the Lch combined signal and the Rch combined signal to the earphone 105.
  • the earphone 105 includes a left output unit 105L and a right output unit 105R as shown in FIG.
  • the left output unit 105L and the right output unit 105R are connected by a neckband 110.
  • a directional microphone 101 is attached to the neckband 110.
  • the directional microphone 101 is provided at the left and right center of the neckband 110. When the user wears 105, the directional microphone 101 is attached to the neckband 110 so as to face backward.
  • the directional microphone 101 collects sound behind the user.
  • the user puts the neckband 110 on the neck and wears the earphone 105.
  • the left output unit 105L outputs the Lch composite signal toward the left ear of the user.
  • the right output unit 105R outputs the Rch composite signal toward the right ear of the user. That is, the earphone 105 reproduces a sound in which ambient sound and music are mixed based on the synthesized signal.
  • the out-of-head localization processing unit 102 performs out-of-head localization processing on at least one of the collected sound signal and the reproduced signal, so that the localization position of the collected sound signal and the localized position of the reproduced signal when output from the earphone 105 are obtained.
  • FIG. 3 is a diagram schematically showing the localization position A of the reproduction signal (music) and the localization position B of the collected sound signal (ambient sound).
  • the out-of-head localization processing unit 102 convolves an out-of-head localization filter with the collected sound signal. Therefore, the collected sound signal is localized outside the user U's head. Specifically, since the localization position B of the collected sound signal is behind the user U, the convolution process is performed using an out-of-head localization filter that is localized backward.
  • the convolution processing is not applied to the reproduction signal.
  • the music played from the music player 103 is not filtered. Therefore, music sounds in the ear as usual and can be localized and heard in the head. That is, the localization position A of the reproduction signal is in the vicinity of the user U's ears 9L and 9R.
  • the localization position A of the reproduction signal and the localization position B of the sound pickup signal are different.
  • the music reproduced by the music player 103 is heard at the ear and is localized in the head, but the ambient sound is localized behind the user U's head. While the music of the reproduction signal can be heard from the ear, the ambient sound of the collected signal can be heard from behind. For the user U, it can be heard that music and ambient sounds are generated at different positions. Therefore, even when the volume level of the collected sound signal is lower than the volume level of the reproduction signal, the user U can easily hear the ambient sound. Further, the synthesizing unit 104 may change the ambient sound level in conjunction with the music playback level so that the ambient sound is not buried in the music.
  • the localization of the music being played at the ear and the ambient sound is separated. For this reason, it is easy to hear the ambient sound even during music reproduction, and the ambient sound can be detected more accurately.
  • the music and ambient sound have the same localization, the ambient sound becomes difficult to hear due to the masking effect. Since the localization position is different, it is possible to hear ambient sounds even when music is being played at a high volume. In other words, even when the relative volume level of the collected sound signal with respect to the volume level of the reproduction signal is small, the user U can easily hear the ambient sound. Therefore, even if the earphone 105 always outputs a sound collection signal, the user U can effectively listen to music. Furthermore, when the ambient sound increases, the ambient sound output from the earphone 105 also increases. Therefore, the user can appropriately listen to ambient sounds and music.
  • the directional microphone 101 collects ambient sounds from the rear. Therefore, it is possible to alert the user U to the rear. For example, when a vehicle such as an automobile, a bicycle, or a motorcycle is approaching from behind, the approach sound of the vehicle is output from the left and right output units 105L and 105R of the earphone 105 as an ambient sound. The ambient sound is localized backward. Therefore, it is possible to accurately detect the approach of the vehicle from the rear, and to prompt attention to the rear.
  • the user U can appropriately listen to the ambient sound. Since the earphone 105 with high sound insulation can be used, sound leakage can be prevented. Furthermore, if the directional microphone 101 is turned off, it is possible to prevent the ambient sound from being heard depending on the use situation. That is, when there is no need to hear ambient sounds, the microphone 101 may be turned off. Alternatively, the synthesis unit 104 may set the volume balance of ambient sounds to zero. For example, when listening to music indoors, the earphone 105 does not output ambient sound, and only the music is reproduced.
  • FIG. 4 is a conceptual diagram showing a configuration for generating a filter used for localization processing.
  • a stereo speaker 5 is arranged behind the listener 1.
  • the stereo speaker 5 has a left speaker 5L and a right speaker 5R.
  • the left speaker 5L is installed diagonally left rear of the listener 1
  • the right speaker 5R is installed diagonally right rear of the listener 1.
  • the left speaker 5L and the right speaker 5R are disposed symmetrically with respect to the listener 1.
  • the left speaker 5L and the right speaker 5R output an impulse sound or the like for performing impulse response measurement.
  • the microphone 2L is installed in the left ear 9L of the listener 1, and the microphone 2R is installed in the right ear 9R. Specifically, it is preferable to install microphones 2L and 2R at the ear canal entrance or the eardrum position of the left ear 9L and the right ear 9R.
  • the microphones 2L and 2R collect the measurement signal output from the stereo speaker 5 and acquire the collected sound signal.
  • the listener 1 is preferably the user U who uses the playback apparatus 100, but transfer characteristics obtained by measurement with a person other than the user U may be used. Further, the listener 1 may be a person or a dummy head. That is, in this embodiment, the listener 1 is a concept including not only a person but also a dummy head.
  • the impulse response is measured by measuring the impulse sound output from the left and right speakers 5L and 5R with the microphones 2L and 2R.
  • the collected sound signal acquired based on the impulse response measurement is stored in a memory or the like.
  • the transfer characteristic Hls between the left speaker 5L and the left microphone 2L, the transfer characteristic Hlo between the left speaker 5L and the right microphone 2R, the transfer characteristic Hro between the right speaker 5R and the left microphone 2L, and the right speaker A transfer characteristic Hrs between 5R and the right microphone 2R is measured. That is, the transfer characteristic Hls is acquired by the left microphone 2L collecting the measurement signal output from the left speaker 5L.
  • the transfer characteristic Hlo is acquired by the right microphone 2R collecting the measurement signal output from the left speaker 5L.
  • the transfer characteristic Hro is acquired.
  • the transfer characteristic Hrs is acquired.
  • a filter corresponding to the transfer characteristics Hls to Hrs measured in this way is generated. Specifically, the transfer characteristics Hls to Hrs are cut out with a predetermined filter length and generated as a filter used for the convolution calculation of the out-of-head localization processing unit 102.
  • a filter may be generated using a head related transfer function (HRTF).
  • the out-of-head localization processing unit 102 convolves the sound pickup signal, which is a monaural signal, with filters corresponding to the four transfer characteristics Hls to Hrs.
  • the out-of-head localization processing unit 102 adds the sound collection signal in which the transfer characteristic Hls is convoluted and the sound collection signal in which the transfer characteristic Hro is convoluted to obtain an Lch sound collection signal.
  • the collected sound signal with the transfer characteristic Hlo convoluted and the collected sound signal with the transfer characteristic Hrs convoluted are added to obtain an Rch sound collected signal.
  • the ambient sound can be localized behind the user U by the impulse response measurement with the stereo speaker 5 installed behind the listener 1.
  • FIG. FIG. 5 is a diagram schematically showing the configuration of the earphone 105 used in the playback apparatus 100 for the playback apparatus according to the present embodiment.
  • directional microphone 101 attached to earphone 105 is different from that in the first embodiment. Since the configuration other than the directional microphone 101 is the same as that of the first embodiment, description thereof will be omitted as appropriate.
  • two directional microphones 101L and 101R are attached to the neckband 110.
  • the directional microphone 101L is provided on the left side of the center of the neckband 110, and the directional microphone 101R is provided on the right side.
  • the directional microphones 101L and 101R are preferably attached symmetrically. Note that the collected sound signals collected by the directional microphones 101L and 101R are stereo signals.
  • the directional microphones 101L and 101R output a sound collection signal to the out-of-head localization processing unit 102.
  • the out-of-head localization processing unit 102 convolves the transmission characteristics Hls and Hlo with the collected sound signal from the directional microphone 101L.
  • the out-of-head localization processing unit 102 convolves the transfer characteristics Hro and Hrs with the sound pickup signal from the directional microphone 101R.
  • the out-of-head localization processing unit 102 adds the sound collection signal in which the transfer characteristic Hls is convoluted and the sound collection signal in which the transfer characteristic Hro is convoluted to obtain an Lch sound collection signal.
  • the collected sound signal with the transfer characteristic Hlo convoluted and the collected sound signal with the transfer characteristic Hrs convoluted are added to obtain an Rch sound collected signal.
  • the same effect as in the first embodiment can be obtained.
  • since directional microphones 101L and 101R are stereo microphones, ambient sounds can be localized backward in a stereo sound field.
  • FIG. 6 is a control block diagram illustrating the configuration of the playback apparatus according to the third embodiment.
  • an unsteady sound detection unit 106 is added. Since the configuration other than the unsteady sound detection unit 106 is the same as that of the first and second embodiments, the description thereof is omitted.
  • the unsteady sound detection unit 106 detects whether or not unsteady sound is generated around the user U. Examples of the unsteady sound include running sounds of vehicles such as automobiles, motorcycles, and bicycles. When an unsteady sound is generated, the unsteady sound detection unit 106 outputs a control signal to the synthesis unit 104.
  • the synthesizing unit 104 controls the volume levels of ambient sounds and music according to the control signal. Specifically, the synthesizing unit 104 increases the volume level of the ambient sound when detecting the unsteady sound.
  • ambient sounds can be output at a high volume level only when unsteady sounds are detected. That is, when an unsteady sound is not detected, an ambient sound can be output at a low volume level.
  • the earphone 105 normally outputs the ambient sound at a low level. However, when the rear unsteady sound is detected, the earphone 105 increases the volume of the ambient sound and outputs it. By doing so, the playback device 100 can emphasize the non-stationary sound. Therefore, it is possible to appropriately alert the rear.
  • FIG. 7 is a flowchart showing processing in the unsteady sound detection unit 106.
  • the directional microphone 101 detects a rear sound (S11).
  • the directional microphone 101 may be a monaural microphone as in the first embodiment, or may be a stereo microphone as in the second embodiment.
  • the collected sound signal from the directional microphone 101 is converted into the frequency domain (S12).
  • the collected sound signal can be converted into the frequency domain by performing a discrete Fourier transform.
  • a sound pickup signal before being subjected to the out-of-head localization processing by the out-of-head localization processing unit 102 can be used.
  • the unsteady sound detection unit 106 monitors the time change of the frequency spectrum (S13). Then, it is determined whether or not the spectrum has changed abruptly (S14). The unsteady sound detection unit 106 obtains the frequency spectrum continuously and calculates the change.
  • the unsteady sound detection unit 106 determines that an unsteady sound is generated behind (S15). For example, the unsteady sound detection unit 106 determines that a vehicle such as a car or a bicycle is approaching from behind. Then, the unsteady sound detection unit 106 outputs a control signal to the synthesis unit 104, and the synthesis unit 104 increases the surrounding volume (S16).
  • the unsteady sound detection unit 106 obtains the peak value of the frequency spectrum acquired continuously. And when there is a big fluctuation
  • the process returns to step S12 because an unsteady sound has occurred.
  • the unsteady sound detection unit 106 continuously monitors the frequency spectrum and determines whether or not there is a large fluctuation in the spectrum. By doing in this way, the unsteady sound detection part 106 can detect the presence or absence of unsteady sound. And when the unsteady sound has generate
  • Embodiment 4 the sound source direction of the unsteady sound is specified using a stereo microphone. For this reason, directional microphones 101L and 101R as shown in FIG. Based on the collected sound signals from the left and right directional microphones 101L and 101R, the unsteady sound detection unit 106 detects the direction of the unsteady sound. For example, the unsteady sound detection unit 106 specifies the sound source direction of the unsteady sound by using the volume difference or arrival time difference between the two collected sound signals. Note that the basic configuration and processing of the playback apparatus 100 are the same as those in the above-described embodiment, and thus description thereof is omitted.
  • FIG. 8 shows a direction based on the user U.
  • the user U is the origin, the front of the user U is 0 °, the right direction is 90 °, the rear is 180 °, and the left direction is 270 °.
  • 90 ° -120 ° in R3 direction 120 ° -150 ° in R2 direction, 150 ° -180 ° in R1 direction, 180 ° -210 ° in L1 direction, 210 ° -240 ° in L2 direction, 240 ° -270 ° Is the L3 direction.
  • the unsteady sound detector 106 monitors the change in sound pressure for each direction.
  • the unsteady sound changes greatly in the R2 direction.
  • the unsteady sound detection unit 106 specifies the sound source direction of the unsteady sound as the R2 direction.
  • the sound pressure in the sound source direction R2 of the collected sound signal is increased and emphasized. By doing so, it is possible to listen to the ambient sound more appropriately. For example, the running sound of the vehicle can be heard from the direction in which the vehicle is approaching. Therefore, the user can perceive the approach of the vehicle more effectively.
  • the unsteady sound detection unit 106 switches the filter according to the sound source direction. That is, the out-of-head localization processing unit 102 stores a filter for each direction of R3 to L3. A sound source direction filter emphasized by the out-of-head localization processing unit 102 may be convoluted with the collected sound signal. By doing so, the ambient sound can be localized in the sound source direction, so that the sound source direction can be emphasized.
  • filters Hls_L3, Hlo_L3, Hro_L3, and Hrs_L3 that emphasize the L3 direction are convoluted with the collected sound signal.
  • filters Hls_L2, Hlo_L2, Hro_L2, and Hrs_L2 that emphasize the L2 direction are convoluted with the collected sound signal.
  • filters Hls_L1, Hlo_L1, Hro_L1, and Hrs_L1 that emphasize the L1 direction are convolved with the collected sound signal.
  • filters Hls_R1, Hlo_R1, Hro_R1, and Hrs_R1 that emphasize the R1 direction are convoluted with the collected sound signal.
  • filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 that emphasize the R2 direction are convoluted with the collected sound signal.
  • the filters Hls_R3, Hlo_R3, Hro_R3, and Hrs_R3 are used to emphasize the R3 direction.
  • FIG. 11 is a flowchart showing a process for specifying the sound source direction.
  • the non-stationary sound detection unit 106 converts the collected sound signal into the frequency domain at regular time intervals (S21). Note that the unsteady sound detection unit 106 converts the collected sound signals acquired by the plurality of directional microphones 101 into the frequency domain. Here, the collected sound signal before the filter is convoluted by the out-of-head localization processing unit 102 is converted into the frequency domain.
  • the unsteady sound detection unit 106 determines whether or not a part of the spectrum has changed significantly (S22). If a part of the spectrum has not changed significantly (NO in S22), the process returns to step S21. When a part of the spectrum changes greatly (YES in S22), it is determined as an unsteady sound (S23).
  • the unsteady sound detection unit 106 obtains a difference M between the volume of the left directional microphone 101L and the volume of the right directional microphone 101R (S24).
  • the unsteady sound detection unit 106 obtains a difference M between the spectrum of the collected sound signal of the directional microphone 101L and the spectrum of the collected sound signal of the directional microphone 101R.
  • the frequency band for obtaining the difference is not particularly limited. For example, the difference of only the peak frequency at which the spectrum has changed greatly may be calculated, or the difference of the entire spectrum may be calculated. Alternatively, the unsteady sound detection unit 106 may obtain the difference between the left and right collected sound signals in the time domain.
  • the unsteady sound detection unit 106 specifies the sound source direction according to the value of the difference M. For example, when the difference M is +6 dB or more, the unsteady sound detection unit 106 determines that there is a sound source in the L3 direction (S25). That is, when the volume of the directional microphone 101L is considerably larger than the volume of the directional microphone 101R, the unsteady sound detection unit 106 determines that the unsteady sound source is in the L3 direction.
  • the unsteady sound detection unit 106 determines that there is a sound source in the L2 direction (S26). When the difference M is 0 dB or more and less than +3 dB, the unsteady sound detection unit 106 determines that there is a sound source in the L1 direction (S27). When the difference M is not less than ⁇ 3 dB and less than 0 dB, the unsteady sound detection unit 106 determines that there is a sound source in the R1 direction (S28).
  • the unsteady sound detection unit 106 determines that there is a sound source in the R2 direction (S29). When the difference M is less than ⁇ 6 dB, the unsteady sound detection unit 106 determines that there is a sound source in the R3 direction (S30).
  • the unsteady sound detection unit 106 specifies the sound source direction according to the difference M in the microphone volume. Specifically, as the difference M is larger, the unsteady sound detection unit 106 determines that there is a sound source in the left direction (270 °). Note that the direction of the sound source may be specified using the phase difference between signals collected by the left and right microphones, not limited to the volume difference. The sound source direction may be specified by combining the volume difference (or volume ratio) and the phase difference.
  • FIG. 12 is a flowchart illustrating processing for switching filters.
  • the out-of-head localization processing unit 102 convolves the rear front filters (Hls, Hlo, Hro, Hrs) with the collected sound signal (S41).
  • the filter (Hls, Hlo, Hro, Hrs) of the front front can be acquired by the measurement shown in FIG.
  • the unsteady sound detection unit 106 determines the sound source direction (S43). That is, the unsteady sound detection unit 106 determines which of the sound source directions is L3 to R3 by the process shown in FIG. Step S43 corresponds to the process shown in FIG.
  • the out-of-head localization processing unit 102 When the sound source direction is the L3 direction (L3 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_L3, Hlo_L3, Hro_L3, and Hrs_L3 in the L3 direction (S44). When the sound source direction is the L2 direction (L2 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_L2, Hlo_L2, Hro_L2, and Hrs_L2 in the L2 direction (S45).
  • the out-of-head localization processing unit 102 convolves the filters Hls_L1, Hlo_L1, Hro_L1, and Hrs_L1 in the L1 direction (S46).
  • the out-of-head localization processing unit 102 When the sound source direction is the R1 direction (R1 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_R1, Hlo_R1, Hro_R1, and Hrs_R1 in the R1 direction (S47). When the sound source direction is the R2 direction (R2 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction (S48).
  • the out-of-head localization processing unit 102 convolves the filters Hls_R3, Hlo_R3, Hro_R3, and Hrs_R3 in the R3 direction (S49).
  • the unsteady sound detection unit 106 identifies the sound source direction of the unsteady sound. Then, the out-of-head localization processing unit 102 convolves the filter set for each direction. By doing so, since the collected sound signal is localized in the sound source direction, it is possible to emphasize the unsteady sound in the sound source direction.
  • FIG. 13 is a diagram schematically illustrating a measurement configuration for generating a filter.
  • FIG. 13 shows a measurement configuration for generating the filters Hls, Hlo, Hro, and Hrs in the rear front and the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction.
  • the installation position of the stereo speaker 5 is changed according to the filter to be generated.
  • the midpoint between the left speaker 5L and the right speaker 5R is in the direction of 180 °.
  • the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction are generated, the midpoint between the left speaker 5L and the right speaker 5R is in the direction of 135 °.
  • the angle corresponds to the angle shown in FIG.
  • a filter for each direction can be generated. That is, the left speaker 5L and the right speaker 5R are rotated by an angle corresponding to the directions L3 to R3 with the listener 1 as the rotation center. Thereby, the filter according to direction can be easily generated.
  • the specified sound source direction is divided into six directions from the L3 direction to the R3 direction, but the number of divisions is not limited to six.
  • the sound source direction only needs to be divided into two or more according to the accuracy of the sound source direction. For example, when the accuracy of the sound source direction is low, it is sufficient that the sound source direction can be specified only in the two directions of the left diagonal rear and the right diagonal rear.
  • the specific direction of the sound source may be 6 or more, or may be less than 6.
  • Examples of localization positions In the above description, the example in which the sound pickup signal (ambient sound) is localized backward and the reproduction signal (music) is played at the ear (localization in the head) has been described. It is not limited. Examples of the localization positions A and B will be described below with reference to FIGS. 14 to 16 are diagrams showing localization positions according to Examples 1 to 3, respectively.
  • Example 1 shown in FIG. 14 the localization position A of the reproduction signal is in front of the user U, and the localization position B of the sound pickup signal is in the ear of the user U (localized in the head). .
  • the out-of-head localization processing unit 102 performs out-of-head localization processing only on the reproduction signal. That is, the out-of-head localization processing unit 102 convolves the filter only with the reproduction signal and does not convolve the filter with the collected sound signal. By doing so, localization positions A and B as shown in FIG. 14 can be realized.
  • the localization position A of the reproduction signal is in front of the user U, and the localization position B of the collected sound signal is in the rear of the user U.
  • the out-of-head localization processing unit 102 performs out-of-head localization processing on both the reproduction signal and the collected sound signal. That is, the out-of-head localization processing unit 102 convolves a reproduced signal with a front localization filter, and convolves a sound localization signal with a rear localization filter. By doing so, localization positions A and B as shown in FIG. 15 can be realized.
  • the front localization filter is generated based on a measurement in which the stereo speaker 5 is installed in front of the listener 1.
  • Example 3 shown in FIG. 16 the localization position A of the reproduction signal is in front of the user U. Then, the localization position B of the collected sound signal changes depending on the presence or absence of the unsteady sound. When an unsteady sound is not detected, the localization position B of the collected sound signal is near the ear (localized in the head). When an unsteady sound is detected, the localization position B ′ of the collected sound signal is rearward. That is, the localization position B of the collected sound signal is changed by switching the filter according to the unsteady sound. By doing so, the localization positions A and B as shown in FIG. 16 can be realized.
  • the localization position A of the reproduction signal and the localization position B of the sound pickup signal are not limited to those described above.
  • it can be localized at an arbitrary position. Only the reproduction signal may be filtered, or only the collected sound signal may be filtered. Alternatively, filter processing may be performed on both the reproduction signal and the collected sound signal.
  • the out-of-head localization processing unit 102 may switch the localization position A of the reproduction signal according to the presence or absence of an unsteady sound. Furthermore, the out-of-head localization processing unit 102 may switch both the localization position A of the reproduction signal and the localization position B of the collected sound signal in accordance with the presence or absence of an unsteady sound.
  • the output unit that outputs the synthesized signal is described as the earphone 105, but the output unit may be a headphone.
  • the sound reproduced by the reproduction signal has been described as music output from the music player 103, it may be a reproduction sound reproduced together with a moving image.
  • the reproduction signal combined with the collected sound signal by the synthesis unit 104 may be a reproduction signal based on movie sound or the like.
  • the number of microphones may be three or more.
  • a microphone that collects ambient sounds is not limited to a directional microphone. For example, when a smartphone application is used as the music player 103, ambient sounds may be collected using a smartphone microphone.
  • the above processing may be executed by a mobile terminal such as a smartphone, or may be executed by an earphone or a DSP (Digital Signal Processor) built in the headphones.
  • a part of the above processing may be executed by the mobile terminal, and the rest may be executed by the DSP built in the earphone or the headphone.
  • the directional microphone 101 is connected to the voice input terminal of the portable terminal.
  • Non-transitory computer readable media include various types of tangible storage media.
  • Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)).
  • the program may be supplied to a computer by various types of temporary computer readable media.
  • Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves.
  • the temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.
  • This application is applicable to a playback device that performs out-of-head localization processing.

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Abstract

There are provided a playback apparatus and a playback method with which a user can appropriately hear ambient sound. A playback apparatus according to the present embodiment is provided with: a music player (103) that outputs a playback signal for playback of music; earphones (105) that have right and left output units that respectively output sound toward right and left ears of a user (U); one or more directional microphones (101) that acquire a sound pickup signal by picking up ambient sound; an out-of-head localization processing unit (102) that makes a localization position of the sound pickup signal different from a localization position of the playback signal when the sound pickup signal and the playback signal are being output from the earphones (105), by subjecting at least one of the sound pickup signal and the playback signal to an out-of-head localization process; and a combining unit (104) that combines and outputs, to the output units, the sound pickup signal and the playback signal.

Description

再生装置、及び再生方法Playback apparatus and playback method
　本発明は、再生装置、及び再生方法に関する。 The present invention relates to a playback device and a playback method.
　デジタルオーディオプレーヤなどの携帯型音楽再生装置によって、屋外でのジョギング中等に音楽を受聴することが可能となっている。屋外でユーザがイヤホンやヘッドホンを装着している場合において、アナウンス音等の周囲の音を聴くことができないと、不都合が生じる場合がある。 A portable music player such as a digital audio player can listen to music while jogging outdoors. When the user wears earphones or headphones outdoors, inconvenience may occur if surrounding sounds such as announcement sounds cannot be heard.
　特許文献１には、ヘッドホンで音楽を聴いている状況下において、ヘッドホンを利用して周囲の音をユーザの耳に届ける携帯機器が開示されている。特許文献１の携帯機器では、マイクによって周囲の音を収音している。そして、携帯機器は、マイクから入力された音をデータベースに格納されたデータと比較して、出力されるべき音であるか否かを判定している。入力音が出力されるべき音と判定した場合、注意喚起モードに移行して、出力音声にミキシングしている。 Patent Document 1 discloses a portable device that uses headphones to deliver ambient sounds to the user's ears while listening to music with headphones. In the portable device of Patent Document 1, ambient sounds are collected by a microphone. Then, the portable device compares the sound input from the microphone with the data stored in the database, and determines whether the sound is to be output. When it is determined that the input sound is to be output, the mode is shifted to the alert mode and is mixed with the output sound.
　特許文献２には、イヤホンとマイクとを有する音再生装置が開示されている。イヤホンは、音信号を耳の中に放音している。マイクは、耳の外の音を収音している。音再生装置は、自動車やバイクなどの移動体の放出音の帯域を通過するフィルタを用いて、移動体の放出音を抽出している。音再生装置は、収音信号の時間勾配を算出して、移動体が近づいているか否かを判定している。移動体が近づいている場合、音再生装置は、イヤホンに供給する音信号のレベルを低下している。このようにすることで、ユーザが、移動体が近づいていることを知ることができる。 Patent Document 2 discloses a sound reproducing device having an earphone and a microphone. The earphone emits a sound signal into the ear. The microphone picks up the sound outside the ear. The sound reproducing device extracts the sound emitted from the moving body using a filter that passes through the band of the sound emitted from the moving body such as an automobile or a motorcycle. The sound reproducing device calculates a time gradient of the collected sound signal and determines whether or not the moving body is approaching. When the moving body is approaching, the sound reproducing device reduces the level of the sound signal supplied to the earphone. By doing in this way, the user can know that the moving body is approaching.
　特許文献３には、音楽用プレーヤから出力される音楽を受聴者の頭外に定位させ、携帯電話機から呼び出される呼び出し音を頭内に定位させるヘッドホン装置が開示されている。 Patent Document 3 discloses a headphone device that localizes music output from a music player outside the listener's head and localizes a ringing tone called from a mobile phone.
特開２００７－２４３４９３号公報JP 2007-243493 A 特開２０１２－２４８９６４号公報JP 2012-248964 A 特開２００４－２０１１９５号公報JP 2004-201195 A
　特許文献１の装置では、注意喚起モードになった場合に、周囲の音を出力音声にミキシングしている。しかしながら、周囲の音と音楽は、いずれも耳元で鳴っているように聴こえる。このため、マスキング効果によって周囲音が聞き取りづらい場合がある。 In the device of Patent Literature 1, when the attention mode is set, the surrounding sound is mixed with the output sound. However, both the surrounding sounds and music can be heard as if they are ringing at the ears. For this reason, it may be difficult to hear ambient sounds due to the masking effect.
　特許文献２の装置では、移動体が近づいている場合に、音信号のレベルを低下させている。しかしながら、特許文献１と同様に、周囲の音と音楽が耳元で鳴っているように聴こえる。このため、マスキング効果によって周囲音が聞き取りづらい場合がある。遮音性の高いイヤホンやヘッドホンを用いた場合、移動体の放出音が遮音されてしまう。また、周囲音を聴けるように遮音性を低くしても、再生している音楽の音量が大きいと周囲音は聴こえづらくなってしまう。したがって、特許文献２の装置では、ユーザが周囲の音を聴くことが困難な場合がある。特許文献３の装置でも、同様に、ユーザが周囲の音を聴くことが困難な場合がある。さらに、遮音性が低いイヤホンを用いた場合、再生音量を大きくすると音漏れしてしまう場合がある。 In the apparatus of Patent Document 2, the level of the sound signal is lowered when the moving body is approaching. However, similar to Patent Document 1, it can be heard that surrounding sounds and music are sounding at the ears. For this reason, it may be difficult to hear ambient sounds due to the masking effect. When earphones or headphones with high sound insulation are used, the sound emitted from the moving body is blocked. Even if the sound insulation is lowered so that the ambient sound can be heard, the ambient sound becomes difficult to hear if the volume of the music being played is high. Therefore, in the apparatus of Patent Document 2, it may be difficult for the user to listen to surrounding sounds. Similarly, in the apparatus of Patent Document 3, it may be difficult for the user to listen to surrounding sounds. Furthermore, when earphones with low sound insulation are used, sound leakage may occur when the playback volume is increased.
　本実施形態は上記の点に鑑みなされたもので、ユーザが適切に周囲の音を聴くことができる再生装置、及び再生方法を提供することを目的とする。 The present embodiment has been made in view of the above points, and an object thereof is to provide a playback device and a playback method that allow a user to appropriately listen to surrounding sounds.
　本実施形態の一態様にかかる再生装置は、再生音を再生するための再生信号を出力する再生部と、ユーザの左右の耳に向けて音をそれぞれ出力する左右の出力ユニットを有する出力部と、周囲音を収音して、収音信号を取得する１つ以上のマイクと、前記収音信号及び前記再生信号の少なくとも一方に対して頭外定位処理を行うことで、前記出力部から出力される際の前記収音信号の定位位置と前記再生信号の定位位置とを異ならせる定位処理部と、前記収音信号と前記再生信号とを合成して、前記出力部に出力する合成部と、を備えたものである。 A playback apparatus according to an aspect of the present embodiment includes a playback unit that outputs a playback signal for playing back playback sound, and an output unit that includes left and right output units that output sound toward the left and right ears of the user, respectively. Output from the output unit by performing out-of-head localization processing on at least one of the collected sound signal and the reproduction signal, and one or more microphones that collect ambient sound and acquire the collected sound signal A localization processing unit for differentiating the localization position of the sound pickup signal and the localization position of the reproduction signal when combined, and a synthesis unit that synthesizes the sound collection signal and the reproduction signal and outputs them to the output unit; , With.
　本実施形態の一態様にかかる再生方法は、再生音を再生するための再生信号を出力するステップと、１つ以上のマイクを用いて周囲音を収音して、収音信号を取得するステップと、前記収音信号及び前記再生信号の少なくとも一方に対して頭外定位処理を行うステップと、前記頭外定位処理の後、前記収音信号と前記再生信号とを合成して、合成信号を生成するステップと、左右の出力ユニットを有する出力部から、ユーザの左右の耳に向けて、前記合成信号をそれぞれ出力するステップと、を備えたものである。 The reproduction method according to one aspect of the present embodiment includes a step of outputting a reproduction signal for reproducing reproduction sound, and a step of collecting ambient sound using one or more microphones to obtain a sound collection signal. A step of performing out-of-head localization processing on at least one of the collected sound signal and the reproduction signal; and after the out-of-head localization processing, combining the collected sound signal and the reproduction signal, A step of generating, and a step of outputting the synthesized signal from the output unit having the left and right output units toward the left and right ears of the user, respectively.
　本実施形態によれば、ユーザが適切に周囲の音を聴くことができる再生装置、及び再生方法を提供することができる。 According to the present embodiment, it is possible to provide a playback device and a playback method that allow a user to appropriately listen to surrounding sounds.
本実施の形態１に係る再生装置の構成を示すブロック図である。1 is a block diagram showing a configuration of a playback device according to a first embodiment. 再生装置に用いられるイヤホンの構成を模式的に示す図である。It is a figure which shows typically the structure of the earphone used for a reproducing | regenerating apparatus. マイクからの収音信号をユーザ後方に定位させるフィルタを生成する構成を示す概念図である。It is a conceptual diagram which shows the structure which produces | generates the filter which localizes the sound collection signal from a microphone to a user back. 再生信号の定位位置Ａと、収音信号の定位位置Ｂを示す図である。It is a figure which shows the localization position A of a reproduction signal, and the localization position B of a sound collection signal. 本実施の形態２に係る再生装置に用いられるイヤホンの構成を模式的に示す図である。It is a figure which shows typically the structure of the earphone used for the reproducing | regenerating apparatus which concerns on this Embodiment 2. FIG. 本実施の形態３に係る再生装置の構成を示すブロック図である。It is a block diagram which shows the structure of the reproducing | regenerating apparatus concerning this Embodiment 3. FIG. 本実施の形態にかかる再生方法において、非定常音を検出するための処理を示すフローチャートである。6 is a flowchart showing a process for detecting an unsteady sound in the reproduction method according to the present embodiment. 非定常音の音源方向を説明するための図である。It is a figure for demonstrating the sound source direction of an unsteady sound. 平常時と非定常音検出時の収音信号の変化を模式的に示す図である。It is a figure which shows typically the change of the sound collection signal at the time of normal time and unsteady sound detection. 平常時と非定常音検出時の信号を模式的に示す図である。It is a figure which shows typically the signal at the time of normal time and unsteady sound detection. 非定常音の音源方向を特定する処理を示すフローチャートである。It is a flowchart which shows the process which specifies the sound source direction of an unsteady sound. 音源方向に応じてフィルタを切り替える処理を示すフローチャートである。It is a flowchart which shows the process which switches a filter according to a sound source direction. 音源方向に応じたフィルタを生成する構成を示す概念図である。It is a conceptual diagram which shows the structure which produces | generates the filter according to a sound source direction. 定位位置の実施例１を示す図である。It is a figure which shows Example 1 of a localization position. 定位位置の実施例２を示す図である。It is a figure which shows Example 2 of a localization position. 定位位置の実施例３を示す図である。It is a figure which shows Example 3 of a localization position.
　本実施の形態にかかる再生装置は、再生音を再生する再生部と、イヤホン又はヘッドホン等の出力部とを備えている。再生部は、典型的には、デジタルオーディオプレーヤ、スマートフォン、タブレット端末等の携帯型音楽プレーヤや携帯型動画プレーヤであり、内部メモリ又はクラウドに予め再生音を録音している。再生音は、音楽や動画再生時の音声である。ユーザがイヤホン又はヘッドホンを装着した状態で、音楽プレーヤが出力部に再生信号を出力する。携帯型の再生装置を用いることで、ユーザが屋外等で音楽を受聴することができる。 The playback device according to the present embodiment includes a playback unit that plays back playback sound and an output unit such as an earphone or headphones. The playback unit is typically a portable music player or a portable video player such as a digital audio player, a smartphone, or a tablet terminal, and records a playback sound in advance in an internal memory or cloud. The playback sound is a sound at the time of music or video playback. With the user wearing earphones or headphones, the music player outputs a playback signal to the output unit. By using a portable playback device, a user can listen to music outdoors.
実施の形態１．
　本実施の形態にかかる再生装置について、図１、図２を用いて説明する。図１は、実施の形態１にかかる再生装置１００の制御構成を示すブロック図である。図２は、再生装置１００に用いられるイヤホン１０５及び指向性マイク１０１の構成を模式的に示す図である。再生装置１００は、指向性マイク１０１と、頭外定位処理部１０２と、音楽プレーヤ１０３と、合成部１０４と、イヤホン１０５と、を備えている。 Embodiment 1 FIG.
The playback apparatus according to this embodiment will be described with reference to FIGS. FIG. 1 is a block diagram of a control configuration of the playback apparatus 100 according to the first embodiment. FIG. 2 is a diagram schematically showing the configuration of the earphone 105 and the directional microphone 101 used in the playback apparatus 100. The playback apparatus 100 includes a directional microphone 101, an out-of-head localization processing unit 102, a music player 103, a synthesis unit 104, and an earphone 105.
　音楽プレーヤ１０３は、例えば、デジタルオーディオプレーヤやスマートフォンのアプリであり、予め録音されている音楽を再生する。音楽プレーヤ１０３は再生した音楽に基づく再生信号を、合成部１０４に出力する。再生信号は、ステレオ入力信号である。すなわち、再生信号は、イヤホン１０５の左出力ユニット１０５Ｌに入力されるＬｃｈのステレオ入力信号と、右出力ユニット１０５Ｒに入力されるＲｃｈのステレオ入力信号を含んでいる。Ｌｃｈのステレオ入力信号は、左出力ユニット１０５Ｌからユーザの左耳に出力され、Ｒｃｈのステレオ入力信号は、右出力ユニット１０５Ｒからユーザの右耳に向けて出力される。ここでは、再生音が音楽であるため、音楽プレーヤ１０３を用いているが、再生音が動画の音声である場合、音楽プレーヤ１０３の代わりに、動画再生可能なアプリ等を用いることができる。 The music player 103 is, for example, a digital audio player or a smartphone application, and plays prerecorded music. The music player 103 outputs a reproduction signal based on the reproduced music to the synthesis unit 104. The reproduction signal is a stereo input signal. That is, the reproduction signal includes an Lch stereo input signal input to the left output unit 105L of the earphone 105 and an Rch stereo input signal input to the right output unit 105R. The Lch stereo input signal is output from the left output unit 105L to the user's left ear, and the Rch stereo input signal is output from the right output unit 105R to the user's right ear. Here, since the playback sound is music, the music player 103 is used. However, when the playback sound is a moving image sound, an application that can play a moving image can be used instead of the music player 103.
　指向性マイク１０１は、ユーザの周囲の音を収音するマイクである。指向性マイク１０１は、周囲音に基づく収音信号を頭外定位処理部１０２に出力する。例えば、指向性マイク１０１は、ユーザの後方で発生する音を収音する。すなわち、指向性マイク１０１は、ユーザの後方に指向性を持つマイクである。 The directional microphone 101 is a microphone that collects sounds around the user. The directional microphone 101 outputs a collected sound signal based on the ambient sound to the out-of-head localization processing unit 102. For example, the directional microphone 101 collects sound generated behind the user. That is, the directional microphone 101 is a microphone having directivity behind the user.
　頭外定位処理部１０２は、指向性マイク１０１からの収音信号に対して、頭外定位処理を行う。具体的には、頭外定位処理部１０２には収音信号に対してフィルタを畳み込む。こうすることで、頭外定位処理部１０２は、定位処理された収音信号を生成する。頭外定位処理部１０２は、定位処理された収音信号を合成部１０４に出力する。頭外定位処理部１０２は、頭部伝達関数ＨＲＴＦ（Ｈｅａｄ　Ｒｅｌａｔｅｄ　Ｔｒａｎｓｆｅｒ　Ｆｕｎｃｔｉｏｎ）等の伝達特性を畳み込むことにより、頭外定位処理を行う。 The out-of-head localization processing unit 102 performs out-of-head localization processing on the collected sound signal from the directional microphone 101. Specifically, the out-of-head localization processing unit 102 convolves a filter with the collected sound signal. By doing so, the out-of-head localization processing unit 102 generates a sound collection signal subjected to localization processing. The out-of-head localization processing unit 102 outputs the collected sound signal subjected to the localization process to the synthesis unit 104. The out-of-head localization processing unit 102 performs out-of-head localization processing by convolving transfer characteristics such as a head-related transfer function HRTF (Head Related Transfer Function).
　具体的には、頭外定位処理部１０２には、左耳に対する伝達特性に応じたＬｃｈのフィルタと、右耳に対する伝達特性に応じたＲｃｈのフィルタが設定されている。頭外定位処理部１０２は、指向性マイク１０１からの収音信号に対してＬｃｈのフィルタを畳み込むことで、定位処理されたＬｃｈの収音信号を生成する。同様に頭外定位処理部１０２は、指向性マイク１０１からの収音信号に対してＲｃｈのフィルタを畳み込むことで、定位処理されたＲｃｈの収音信号を生成する。頭外定位処理部１０２に用いられるフィルタについては後述する。 Specifically, in the out-of-head localization processing unit 102, an Lch filter corresponding to the transfer characteristic for the left ear and an Rch filter corresponding to the transfer characteristic for the right ear are set. The out-of-head localization processing unit 102 convolves an Lch filter with the collected sound signal from the directional microphone 101 to generate a localized Lch collected sound signal. Similarly, the out-of-head localization processing unit 102 convolves an Rch filter with the collected sound signal from the directional microphone 101 to generate a localized Rch collected sound signal. The filter used for the out-of-head localization processing unit 102 will be described later.
　合成部１０４は、定位処理された収音信号と、再生信号とを合成するミキサーである。具体的には、合成部１０４は、収音信号と再生信号の音量バランスを調整して、合成することで、合成信号を生成する。合成部１０４は合成信号をイヤホン１０５に出力する。 The synthesizing unit 104 is a mixer that synthesizes the localized sound collection signal and the reproduction signal. Specifically, the synthesis unit 104 generates a synthesized signal by adjusting and synthesizing the volume balance between the collected sound signal and the reproduction signal. The combining unit 104 outputs the combined signal to the earphone 105.
　例えば、合成部１０４は、収音信号と再生信号とに対して、音量バランスに応じた係数を乗じる。そして、合成部１０４は、係数が乗じられた収音信号と再生信号とを加算することで、合成信号を生成する。また、合成部１０４は、Ｌｃｈの信号とＲｃｈの信号とのそれぞれに対して合成処理を行う。すなわち、合成部１０４は、Ｌｃｈの収音信号とＬｃｈの再生信号を加算することで、Ｌｃｈの合成信号を生成する。同様に、合成部１０４は、Ｒｃｈの再生信号とＲｃｈの収音信号とを加算することで、Ｒｃｈの合成信号を生成する。合成部１０４はＬｃｈの合成信号とＲｃｈの合成信号をイヤホン１０５に出力する。 For example, the synthesis unit 104 multiplies the sound collection signal and the reproduction signal by a coefficient corresponding to the volume balance. Then, the synthesis unit 104 generates a synthesized signal by adding the collected sound signal multiplied by the coefficient and the reproduction signal. The synthesizing unit 104 performs synthesis processing on each of the Lch signal and the Rch signal. That is, the combining unit 104 adds the Lch sound pickup signal and the Lch reproduction signal to generate an Lch combined signal. Similarly, the synthesis unit 104 adds the Rch reproduction signal and the Rch sound collection signal to generate an Rch synthesis signal. The combining unit 104 outputs the Lch combined signal and the Rch combined signal to the earphone 105.
　イヤホン１０５は、図２に示すように、左出力ユニット１０５Ｌと右出力ユニット１０５Ｒとを備えている。そして、左出力ユニット１０５Ｌと右出力ユニット１０５Ｒは、ネックバンド１１０で連結されている。ネックバンド１１０には、指向性マイク１０１が取り付けられている。指向性マイク１０１は、ネックバンド１１０の左右中央に設けられている。ユーザが１０５を装着した時に、指向性マイク１０１が後方を向くように、ネックバンド１１０に取り付けられている。指向性マイク１０１は、ユーザの後方の音を収音する。 The earphone 105 includes a left output unit 105L and a right output unit 105R as shown in FIG. The left output unit 105L and the right output unit 105R are connected by a neckband 110. A directional microphone 101 is attached to the neckband 110. The directional microphone 101 is provided at the left and right center of the neckband 110. When the user wears 105, the directional microphone 101 is attached to the neckband 110 so as to face backward. The directional microphone 101 collects sound behind the user.
　ユーザがネックバンド１１０を首に掛けて、イヤホン１０５を装着する。左出力ユニット１０５Ｌは、Ｌｃｈの合成信号をユーザの左耳に向けて出力する。右出力ユニット１０５Ｒは、Ｒｃｈの合成信号をユーザの右耳に向けて出力する。すなわち、イヤホン１０５は、合成信号に基づいて、周囲音と音楽がミキシングされた音を再生する。 The user puts the neckband 110 on the neck and wears the earphone 105. The left output unit 105L outputs the Lch composite signal toward the left ear of the user. The right output unit 105R outputs the Rch composite signal toward the right ear of the user. That is, the earphone 105 reproduces a sound in which ambient sound and music are mixed based on the synthesized signal.
　このようにすることで、ユーザの周囲で発生した周囲音を頭外に定位させることができる。一方、音楽プレーヤ１０３で再生された音楽は、頭外定位されていないため、ユーザの耳元で鳴り、頭内に定位して聴こえる。収音信号の定位位置と、再生信号の定位位置とが異なっている。周囲音と音楽の定位を分離している。頭外定位処理部１０２は、収音信号及び再生信号の少なくとも一方に対して頭外定位処理を行うことで、イヤホン１０５から出力される際の収音信号の定位位置と再生信号の定位位置とを異ならせている。 In this way, ambient sounds generated around the user can be localized outside the head. On the other hand, the music played back by the music player 103 is not localized outside the head, so it can be heard at the user's ear and localized in the head. The localization position of the collected sound signal is different from the localization position of the reproduction signal. Ambient sounds and music localization are separated. The out-of-head localization processing unit 102 performs out-of-head localization processing on at least one of the collected sound signal and the reproduced signal, so that the localization position of the collected sound signal and the localized position of the reproduced signal when output from the earphone 105 are obtained. Are different.
　図３を用いて、収音信号の定位位置と再生信号の定位位置とについて説明する。図３は、再生信号（音楽）の定位位置Ａと収音信号（周囲音）の定位位置Ｂとを模式的に示す図である。 Referring to FIG. 3, the localization position of the collected sound signal and the localization position of the reproduction signal will be described. FIG. 3 is a diagram schematically showing the localization position A of the reproduction signal (music) and the localization position B of the collected sound signal (ambient sound).
　上記したように、頭外定位処理部１０２は、収音信号に対して頭外定位用のフィルタを畳み込んでいる。したがって、収音信号がユーザＵの頭外に定位している。具体的には、収音信号の定位位置ＢがユーザＵの後方であるため、後方に定位する頭外定位フィルタを用いて畳み込み処理を行う。 As described above, the out-of-head localization processing unit 102 convolves an out-of-head localization filter with the collected sound signal. Therefore, the collected sound signal is localized outside the user U's head. Specifically, since the localization position B of the collected sound signal is behind the user U, the convolution process is performed using an out-of-head localization filter that is localized backward.
　一方、再生信号に対しては、畳み込み処理が施されていない。すなわち、音楽プレーヤ１０３から再生される音楽には、フィルタ処理が施されていない。よって、音楽は通常通りに耳元で鳴るため、頭内に定位して聴こえる。すなわち、再生信号の定位位置ＡはユーザＵの耳９Ｌ、９Ｒの近傍になっている。 On the other hand, the convolution processing is not applied to the reproduction signal. In other words, the music played from the music player 103 is not filtered. Therefore, music sounds in the ear as usual and can be localized and heard in the head. That is, the localization position A of the reproduction signal is in the vicinity of the user U's ears 9L and 9R.
　このように、再生信号の定位位置Ａと収音信号の定位位置Ｂとが異なっている。周囲音のみにフィルタを畳み込むことにより、音楽プレーヤ１０３で再生される音楽は耳元で鳴るため、頭内に定位するが、周囲音はユーザＵの頭部の後方に定位する。再生信号の音楽は耳元から聴こえるのに対して、収音信号の周囲音が後方から聴こえる。ユーザＵにとって、音楽と周囲音が異なる位置で発生しているように聴こえる。したがって、収音信号の音量レベルが再生信号の音量レベルに対して低い場合であっても、ユーザＵが周囲音を聴きやすくなる。また、合成部１０４は、音楽再生レベルに連動して周囲音のレベルを変化させ、周囲音が音楽に埋もれないようにしてもよい。 Thus, the localization position A of the reproduction signal and the localization position B of the sound pickup signal are different. By convolving the filter only with the ambient sound, the music reproduced by the music player 103 is heard at the ear and is localized in the head, but the ambient sound is localized behind the user U's head. While the music of the reproduction signal can be heard from the ear, the ambient sound of the collected signal can be heard from behind. For the user U, it can be heard that music and ambient sounds are generated at different positions. Therefore, even when the volume level of the collected sound signal is lower than the volume level of the reproduction signal, the user U can easily hear the ambient sound. Further, the synthesizing unit 104 may change the ambient sound level in conjunction with the music playback level so that the ambient sound is not buried in the music.
　周囲音のみを後方に定位させることにより、耳元で鳴っている音楽と周囲音との定位が分離される。このため、音楽再生中でも周囲音が聴き取りやすくなり、周囲音をより正確に察知することができる。一方、音楽と周囲音が同じ定位だと、マスキング効果により周囲音が聞き取りづらくなってしまう。定位位置が異なるため、大音量で音楽を再生している場合でも周囲音を聴き取ることが出来るようになる。換言すると、再生信号の音量レベルに対する収音信号の相対的な音量レベルが小さい場合であっても、ユーザＵが周囲音を聴き取りやすい。よって、イヤホン１０５が収音信号を常時出力していたとしても、ユーザＵが効果的に音楽を聴くことができる。さらに、周囲音が大きくなると、イヤホン１０５から出力される周囲音も大きくなる。よって、ユーザが適切に周囲音と音楽とを聴き分けることができる。 By localizing only the ambient sound backward, the localization of the music being played at the ear and the ambient sound is separated. For this reason, it is easy to hear the ambient sound even during music reproduction, and the ambient sound can be detected more accurately. On the other hand, if the music and ambient sound have the same localization, the ambient sound becomes difficult to hear due to the masking effect. Since the localization position is different, it is possible to hear ambient sounds even when music is being played at a high volume. In other words, even when the relative volume level of the collected sound signal with respect to the volume level of the reproduction signal is small, the user U can easily hear the ambient sound. Therefore, even if the earphone 105 always outputs a sound collection signal, the user U can effectively listen to music. Furthermore, when the ambient sound increases, the ambient sound output from the earphone 105 also increases. Therefore, the user can appropriately listen to ambient sounds and music.
　また、指向性マイク１０１が後方からの周囲音を収音する。よって、ユーザＵに対して、後方への注意喚起を行うことができる。例えば、後方から自動車、自転車、バイクなどの車両が接近している場合、車両の接近音が周囲音としてイヤホン１０５の左右の出力ユニット１０５Ｌ、１０５Ｒから出力されている。そして、周囲音が後方に定位している。よって、後方からの車両の接近を正確に察知することができ、後方への注意を促すことができる。 Also, the directional microphone 101 collects ambient sounds from the rear. Therefore, it is possible to alert the user U to the rear. For example, when a vehicle such as an automobile, a bicycle, or a motorcycle is approaching from behind, the approach sound of the vehicle is output from the left and right output units 105L and 105R of the earphone 105 as an ambient sound. The ambient sound is localized backward. Therefore, it is possible to accurately detect the approach of the vehicle from the rear, and to prompt attention to the rear.
　遮音性の高いイヤホン１０５を用いた場合でも、ユーザＵが適切に周囲音を聴くことができる。遮音性の高いイヤホン１０５を用いることができるため、音漏れを防止することができる。さらに、指向性マイク１０１をオフするなどしておけば、使用状況に応じて周囲音を聴こえなくすることも可能である。すなわち、周囲音を聞く必要がない場合は、マイク１０１をオフしておけばよい。あるいは、合成部１０４が周囲音の音量バランスを０にすればよい。室内で音楽を聴く場合などは、イヤホン１０５が周囲音を出力せずに、音楽のみ再生すればよい。 Even when the earphone 105 having high sound insulation is used, the user U can appropriately listen to the ambient sound. Since the earphone 105 with high sound insulation can be used, sound leakage can be prevented. Furthermore, if the directional microphone 101 is turned off, it is possible to prevent the ambient sound from being heard depending on the use situation. That is, when there is no need to hear ambient sounds, the microphone 101 may be turned off. Alternatively, the synthesis unit 104 may set the volume balance of ambient sounds to zero. For example, when listening to music indoors, the earphone 105 does not output ambient sound, and only the music is reproduced.
　頭外定位処理部１０２における定位処理について、図４を用いて説明する。図４は、定位処理に用いられるフィルタを生成する構成を示す概念図である。 The localization process in the out-of-head localization processing unit 102 will be described with reference to FIG. FIG. 4 is a conceptual diagram showing a configuration for generating a filter used for localization processing.
　また、受聴者１の後方には、ステレオスピーカ５が配置されている。ステレオスピーカ５は、左スピーカ５Ｌと右スピーカ５Ｒを有している。左スピーカ５Ｌは受聴者１の斜め左後方に設置され、右スピーカ５Ｒは、受聴者１の斜め右後方に設置されている。左スピーカ５Ｌと右スピーカ５Ｒは受聴者１に対して左右対称に配置されている。左スピーカ５Ｌと右スピーカ５Ｒは、インパルス応答測定を行うためのインパルス音等を出力する。 Further, a stereo speaker 5 is arranged behind the listener 1. The stereo speaker 5 has a left speaker 5L and a right speaker 5R. The left speaker 5L is installed diagonally left rear of the listener 1, and the right speaker 5R is installed diagonally right rear of the listener 1. The left speaker 5L and the right speaker 5R are disposed symmetrically with respect to the listener 1. The left speaker 5L and the right speaker 5R output an impulse sound or the like for performing impulse response measurement.
　受聴者１の左耳９Ｌにはマイク２Ｌが設置され、右耳９Ｒにはマイク２Ｒが設置されている。具体的には、左耳９Ｌ、右耳９Ｒの外耳道入口又は鼓膜位置にマイク２Ｌ、２Ｒを設置することが好ましい。マイク２Ｌ、２Ｒは、ステレオスピーカ５から出力された測定信号を収音して、収音信号を取得する。なお、受聴者１は、再生装置１００を用いるユーザＵであることが好ましいが、ユーザＵ以外の人での測定で得られた伝達特性を用いてもよい。さらに、受聴者１は、人でもよく、ダミーヘッドでもよい。すなわち、本実施形態において、受聴者１は人だけでなく、ダミーヘッドを含む概念である。 The microphone 2L is installed in the left ear 9L of the listener 1, and the microphone 2R is installed in the right ear 9R. Specifically, it is preferable to install microphones 2L and 2R at the ear canal entrance or the eardrum position of the left ear 9L and the right ear 9R. The microphones 2L and 2R collect the measurement signal output from the stereo speaker 5 and acquire the collected sound signal. Note that the listener 1 is preferably the user U who uses the playback apparatus 100, but transfer characteristics obtained by measurement with a person other than the user U may be used. Further, the listener 1 may be a person or a dummy head. That is, in this embodiment, the listener 1 is a concept including not only a person but also a dummy head.
　上記のように、左右のスピーカ５Ｌ、５Ｒで出力されたインパルス音をマイク２Ｌ、２Ｒで測定することでインパルス応答が測定される。インパルス応答測定に基づいて取得した収音信号はメモリなどに記憶される。これにより、左スピーカ５Ｌと左マイク２Ｌとの間の伝達特性Ｈｌｓ、左スピーカ５Ｌと右マイク２Ｒとの間の伝達特性Ｈｌｏ、右スピーカ５Ｒと左マイク２Ｌとの間の伝達特性Ｈｒｏ、右スピーカ５Ｒと右マイク２Ｒとの間の伝達特性Ｈｒｓが測定される。すなわち、左スピーカ５Ｌから出力された測定信号を左マイク２Ｌが収音することで、伝達特性Ｈｌｓが取得される。左スピーカ５Ｌから出力された測定信号を右マイク２Ｒが収音することで、伝達特性Ｈｌｏが取得される。右スピーカ５Ｒから出力された測定信号を左マイク２Ｌが収音することで、伝達特性Ｈｒｏが取得される。右スピーカ５Ｒから出力された測定信号を右マイク２Ｒが収音することで、伝達特性Ｈｒｓが取得される。 As described above, the impulse response is measured by measuring the impulse sound output from the left and right speakers 5L and 5R with the microphones 2L and 2R. The collected sound signal acquired based on the impulse response measurement is stored in a memory or the like. Thereby, the transfer characteristic Hls between the left speaker 5L and the left microphone 2L, the transfer characteristic Hlo between the left speaker 5L and the right microphone 2R, the transfer characteristic Hro between the right speaker 5R and the left microphone 2L, and the right speaker A transfer characteristic Hrs between 5R and the right microphone 2R is measured. That is, the transfer characteristic Hls is acquired by the left microphone 2L collecting the measurement signal output from the left speaker 5L. The transfer characteristic Hlo is acquired by the right microphone 2R collecting the measurement signal output from the left speaker 5L. When the left microphone 2L collects the measurement signal output from the right speaker 5R, the transfer characteristic Hro is acquired. When the right microphone 2R collects the measurement signal output from the right speaker 5R, the transfer characteristic Hrs is acquired.
　このように測定された伝達特性Ｈｌｓ～Ｈｒｓに応じたフィルタが生成される。具体的には、伝達特性Ｈｌｓ～Ｈｒｓが所定のフィルタ長で切り出されて、頭外定位処理部１０２の畳み込み演算に用いられるフィルタとして生成される。また、頭部伝達関数（ＨＲＴＦ）を用いて、フィルタを生成してもよい。 A filter corresponding to the transfer characteristics Hls to Hrs measured in this way is generated. Specifically, the transfer characteristics Hls to Hrs are cut out with a predetermined filter length and generated as a filter used for the convolution calculation of the out-of-head localization processing unit 102. A filter may be generated using a head related transfer function (HRTF).
　本実施の形態では、指向性マイク１０１がモノラルマイクであるので、頭外定位処理部１０２は、モノラル信号である収音信号に、４つの伝達特性Ｈｌｓ～Ｈｒｓに応じたフィルタをそれぞれ畳み込む。頭外定位処理部１０２は、伝達特性Ｈｌｓが畳み込まれた収音信号と伝達特性Ｈｒｏが畳み込まれた収音信号とを加算して、Ｌｃｈの収音信号とする。伝達特性Ｈｌｏが畳み込まれた収音信号と伝達特性Ｈｒｓが畳み込まれた収音信号とを加算して、Ｒｃｈの収音信号とする。このように受聴者１の後方にステレオスピーカ５を設置した状態でのインパルス応答測定によって、ユーザＵの後方に周囲音を定位させることができる。 In this embodiment, since the directional microphone 101 is a monaural microphone, the out-of-head localization processing unit 102 convolves the sound pickup signal, which is a monaural signal, with filters corresponding to the four transfer characteristics Hls to Hrs. The out-of-head localization processing unit 102 adds the sound collection signal in which the transfer characteristic Hls is convoluted and the sound collection signal in which the transfer characteristic Hro is convoluted to obtain an Lch sound collection signal. The collected sound signal with the transfer characteristic Hlo convoluted and the collected sound signal with the transfer characteristic Hrs convoluted are added to obtain an Rch sound collected signal. Thus, the ambient sound can be localized behind the user U by the impulse response measurement with the stereo speaker 5 installed behind the listener 1.
実施の形態２．
　本実施の形態にかかる再生装置について、図５は再生装置１００に用いられるイヤホン１０５の構成を模式的に示す図である。なお、本実施の形態では、イヤホン１０５に装着された指向性マイク１０１が実施の形態１と異なっている。なお、指向性マイク１０１以外の構成については、実施の形態１と同様であるため、適宜説明を省略する。 Embodiment 2. FIG.
FIG. 5 is a diagram schematically showing the configuration of the earphone 105 used in the playback apparatus 100 for the playback apparatus according to the present embodiment. In the present embodiment, directional microphone 101 attached to earphone 105 is different from that in the first embodiment. Since the configuration other than the directional microphone 101 is the same as that of the first embodiment, description thereof will be omitted as appropriate.
　本実施の形態２では、図５に示すように、ネックバンド１１０に２つの指向性マイク１０１Ｌ、１０１Ｒに取り付けられている。指向性マイク１０１Ｌは、ネックバンド１１０の中央よりも左側に設けられ、指向性マイク１０１Ｒは右側に設けられている。指向性マイク１０１Ｌ、１０１Ｒは左右対称に取り付けられることが好ましい。なお、指向性マイク１０１Ｌ、１０１Ｒで収音された収音信号はステレオ信号となる。指向性マイク１０１Ｌ、１０１Ｒは、頭外定位処理部１０２に収音信号を出力する In the second embodiment, as shown in FIG. 5, two directional microphones 101L and 101R are attached to the neckband 110. The directional microphone 101L is provided on the left side of the center of the neckband 110, and the directional microphone 101R is provided on the right side. The directional microphones 101L and 101R are preferably attached symmetrically. Note that the collected sound signals collected by the directional microphones 101L and 101R are stereo signals. The directional microphones 101L and 101R output a sound collection signal to the out-of-head localization processing unit 102.
　頭外定位処理部１０２は、指向性マイク１０１Ｌからの収音信号には、伝達特性Ｈｌｓ、Ｈｌｏをそれぞれ畳み込む。頭外定位処理部１０２は、指向性マイク１０１Ｒからの収音信号に対して、伝達特性Ｈｒｏ、Ｈｒｓをそれぞれ畳み込む。頭外定位処理部１０２は、伝達特性Ｈｌｓが畳み込まれた収音信号と伝達特性Ｈｒｏが畳み込まれた収音信号とを加算して、Ｌｃｈの収音信号とする。伝達特性Ｈｌｏが畳み込まれた収音信号と伝達特性Ｈｒｓが畳み込まれた収音信号とを加算して、Ｒｃｈの収音信号とする。本実施の形態においても実施の形態１と同様の効果を得ることができる。また、本実施の形態では、指向性マイク１０１Ｌ、１０１Ｒがステレオマイクであるため、周囲音を後方にステレオ音場で定位させることができる。 The out-of-head localization processing unit 102 convolves the transmission characteristics Hls and Hlo with the collected sound signal from the directional microphone 101L. The out-of-head localization processing unit 102 convolves the transfer characteristics Hro and Hrs with the sound pickup signal from the directional microphone 101R. The out-of-head localization processing unit 102 adds the sound collection signal in which the transfer characteristic Hls is convoluted and the sound collection signal in which the transfer characteristic Hro is convoluted to obtain an Lch sound collection signal. The collected sound signal with the transfer characteristic Hlo convoluted and the collected sound signal with the transfer characteristic Hrs convoluted are added to obtain an Rch sound collected signal. Also in the present embodiment, the same effect as in the first embodiment can be obtained. In the present embodiment, since directional microphones 101L and 101R are stereo microphones, ambient sounds can be localized backward in a stereo sound field.
実施の形態３．
　本実施の形態にかかる再生装置について、図６を用いて説明する。図６は、実施の形態３にかかる再生装置の構成を示す制御ブロック図である。本実施の形態では、非定常音検出部１０６が追加されている。なお、非定常音検出部１０６以外の構成については、実施の形態１、２と同様であるため説明を省略する。 Embodiment 3 FIG.
The playback apparatus according to this embodiment will be described with reference to FIG. FIG. 6 is a control block diagram illustrating the configuration of the playback apparatus according to the third embodiment. In the present embodiment, an unsteady sound detection unit 106 is added. Since the configuration other than the unsteady sound detection unit 106 is the same as that of the first and second embodiments, the description thereof is omitted.
　非定常音検出部１０６はユーザＵの周囲で非定常音が発生しているか否かを検出する。非定常音としては、自動車、バイク、自転車等の乗り物の走行音が挙げられる。非定常音が発生した場合、非定常音検出部１０６は制御信号を合成部１０４に出力する。合成部１０４は、制御信号に応じて、周囲音と音楽の音量レベルを制御する。具体的には、合成部１０４は、非定常音の検出時に、周囲音の音量レベルを高くする。 The unsteady sound detection unit 106 detects whether or not unsteady sound is generated around the user U. Examples of the unsteady sound include running sounds of vehicles such as automobiles, motorcycles, and bicycles. When an unsteady sound is generated, the unsteady sound detection unit 106 outputs a control signal to the synthesis unit 104. The synthesizing unit 104 controls the volume levels of ambient sounds and music according to the control signal. Specifically, the synthesizing unit 104 increases the volume level of the ambient sound when detecting the unsteady sound.
　このようにすることで、非定常音の検出時のみ、高い音量レベルで周囲音を出力することができる。すなわち、非定常音が検出されていないときは、低い音量レベルで周囲音を出力することができる。イヤホン１０５は、通常、周囲音を低めに出力しているが、後方の非定常音を検出した場合に、周囲音の音量を上げて出力する。こうすることで、再生装置１００が、非定常音を強調することができる。よって、後方への注意喚起を適切に行うことができる。 In this way, ambient sounds can be output at a high volume level only when unsteady sounds are detected. That is, when an unsteady sound is not detected, an ambient sound can be output at a low volume level. The earphone 105 normally outputs the ambient sound at a low level. However, when the rear unsteady sound is detected, the earphone 105 increases the volume of the ambient sound and outputs it. By doing so, the playback device 100 can emphasize the non-stationary sound. Therefore, it is possible to appropriately alert the rear.
　本実施の形態にかかる再生方法について、図７を用いて説明する。図７は非定常音検出部１０６における処理を示すフローチャートである。 The reproduction method according to this embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing processing in the unsteady sound detection unit 106.
　まず、指向性マイク１０１が後方音を検出する（Ｓ１１）。なお、指向性マイク１０１は実施の形態１のようにモノラルマイクであってもよいし、実施の形態２のようにステレオマイクであってもよい。次に、指向性マイク１０１からの収音信号を周波数領域に変換する（Ｓ１２）。たとえば、収音信号を離散フーリエ変換することで、周波数領域に変換することができる。なお、収音信号は、頭外定位処理部１０２によって頭外定位処理する前の収音信号を用いることができる。 First, the directional microphone 101 detects a rear sound (S11). The directional microphone 101 may be a monaural microphone as in the first embodiment, or may be a stereo microphone as in the second embodiment. Next, the collected sound signal from the directional microphone 101 is converted into the frequency domain (S12). For example, the collected sound signal can be converted into the frequency domain by performing a discrete Fourier transform. As the sound pickup signal, a sound pickup signal before being subjected to the out-of-head localization processing by the out-of-head localization processing unit 102 can be used.
　非定常音検出部１０６は、周波数スペクトルの時間変化を監視する（Ｓ１３）。そして、スペクトルが急激に変化したか否かを判定する（Ｓ１４）。非定常音検出部１０６は、周波数スペクトルを連続して取得して、その変化を算出する。 The unsteady sound detection unit 106 monitors the time change of the frequency spectrum (S13). Then, it is determined whether or not the spectrum has changed abruptly (S14). The unsteady sound detection unit 106 obtains the frequency spectrum continuously and calculates the change.
　スペクトルが急激に変化した場合（Ｓ１４のＹＥＳ）、非定常音検出部１０６は、後方に非定常音が発生していると判断する（Ｓ１５）。例えば、非定常音検出部１０６は、後方から車や自転車等の車両が接近していると判断する。すると、非定常音検出部１０６が制御信号を合成部１０４に出力して、合成部１０４が周囲の音量を上げる（Ｓ１６）。 When the spectrum changes abruptly (YES in S14), the unsteady sound detection unit 106 determines that an unsteady sound is generated behind (S15). For example, the unsteady sound detection unit 106 determines that a vehicle such as a car or a bicycle is approaching from behind. Then, the unsteady sound detection unit 106 outputs a control signal to the synthesis unit 104, and the synthesis unit 104 increases the surrounding volume (S16).
　例えば、ユーザＵに車両が接近している場合、スペクトルが大きく変化する。非定常音検出部１０６は、連続して取得された周波数スペクトルのピーク値を求める。そして、ピーク値に大きな変動があった場合、非定常音検出部１０６は、スペクトルが急激に変化したと判定する。連続する２つのスペクトルのピーク値の差分をしきい値と比較することで、急激に変動したか否かを判定する。 For example, when the vehicle approaches the user U, the spectrum changes greatly. The unsteady sound detection unit 106 obtains the peak value of the frequency spectrum acquired continuously. And when there is a big fluctuation | variation in a peak value, the unsteady sound detection part 106 determines with the spectrum having changed rapidly. By comparing the difference between the peak values of two consecutive spectra with a threshold value, it is determined whether or not there is a sudden change.
　スペクトルが急激に変化していない場合（Ｓ１４のＮＯ）、非定常音が発生していなので、ステップＳ１２に戻る。非定常音検出部１０６は、周波数スペクトルを継続的に監視して、スペクトルに大きな変動があったか否かを判定する。このようにすることで、非定常音検出部１０６は非定常音の有無を検出することができる。そして、後方に非定常音が発生している場合に、周囲音の音量レベルを高くすることができる。よって、後方への注意喚起を適切に行うことができる。 If the spectrum does not change abruptly (NO in S14), the process returns to step S12 because an unsteady sound has occurred. The unsteady sound detection unit 106 continuously monitors the frequency spectrum and determines whether or not there is a large fluctuation in the spectrum. By doing in this way, the unsteady sound detection part 106 can detect the presence or absence of unsteady sound. And when the unsteady sound has generate | occur | produced back, the volume level of ambient sound can be made high. Therefore, it is possible to appropriately alert the rear.
実施の形態４．
　本実施の形態では、ステレオマイクを用いて非定常音の音源方向を特定している。そのため、図５に示すような、指向性マイク１０１Ｌ、１０１Ｒをネックバンド１１０に設けている。左右の指向性マイク１０１Ｌ、１０１Ｒからの収音信号に基づいて、非定常音検出部１０６が非定常音の方向を検出している。例えば、非定常音検出部１０６が、２つの収音信号の音量差や到達時間差を用いて、非定常音の音源方向を特定する。なお、再生装置１００の基本的な構成、及び処理については、上記した実施の形態と同様であるため、説明を省略する。 Embodiment 4 FIG.
In this embodiment, the sound source direction of the unsteady sound is specified using a stereo microphone. For this reason, directional microphones 101L and 101R as shown in FIG. Based on the collected sound signals from the left and right directional microphones 101L and 101R, the unsteady sound detection unit 106 detects the direction of the unsteady sound. For example, the unsteady sound detection unit 106 specifies the sound source direction of the unsteady sound by using the volume difference or arrival time difference between the two collected sound signals. Note that the basic configuration and processing of the playback apparatus 100 are the same as those in the above-described embodiment, and thus description thereof is omitted.
　図８に、ユーザＵを基準とする方向を示す。図８では、ユーザＵを原点として、ユーザＵの前方を０°、右方向を９０°、後方を１８０°、左方向を２７０°としている。９０°～１２０°をＲ３方向、１２０°～１５０°をＲ２方向、１５０°～１８０°をＲ１方向、１８０°～２１０°をＬ１方向、２１０°～２４０°をＬ２方向、２４０°～２７０°をＬ３方向とする。 FIG. 8 shows a direction based on the user U. In FIG. 8, the user U is the origin, the front of the user U is 0 °, the right direction is 90 °, the rear is 180 °, and the left direction is 270 °. 90 ° -120 ° in R3 direction, 120 ° -150 ° in R2 direction, 150 ° -180 ° in R1 direction, 180 ° -210 ° in L1 direction, 210 ° -240 ° in L2 direction, 240 ° -270 ° Is the L3 direction.
　非定常音検出部１０６は、方向別に音圧の変化を監視する。図９では、Ｒ２方向において、非定常音が大きく変化している。この場合、非定常音検出部１０６は、非定常音の音源方向をＲ２方向と特定する。そして、図１０に示すように、収音信号の音源方向Ｒ２の音圧を上げて、強調する。このようにすることで、より周囲音を適切に聴くことができる。例えば、車両が接近している方向から車両の走行音が聴こえる。よって、より効果的にユーザが車両の接近を察知することができる。 The unsteady sound detector 106 monitors the change in sound pressure for each direction. In FIG. 9, the unsteady sound changes greatly in the R2 direction. In this case, the unsteady sound detection unit 106 specifies the sound source direction of the unsteady sound as the R2 direction. Then, as shown in FIG. 10, the sound pressure in the sound source direction R2 of the collected sound signal is increased and emphasized. By doing so, it is possible to listen to the ambient sound more appropriately. For example, the running sound of the vehicle can be heard from the direction in which the vehicle is approaching. Therefore, the user can perceive the approach of the vehicle more effectively.
　具体的には、非定常音検出部１０６が、音源方向に応じて、フィルタを切り替える。すなわち、頭外定位処理部１０２は、Ｒ３～Ｌ３の方向毎にフィルタを格納している。そして、頭外定位処理部１０２が強調する音源方向のフィルタを収音信号に畳み込めばよい。このようにすることで、音源方向に周囲音を定位させることができるため、音源方向を強調することができる。 Specifically, the unsteady sound detection unit 106 switches the filter according to the sound source direction. That is, the out-of-head localization processing unit 102 stores a filter for each direction of R3 to L3. A sound source direction filter emphasized by the out-of-head localization processing unit 102 may be convoluted with the collected sound signal. By doing so, the ambient sound can be localized in the sound source direction, so that the sound source direction can be emphasized.
　具体的には、音源がＬ３方向である場合、Ｌ３方向を強調するフィルタＨｌｓ＿Ｌ３、Ｈｌｏ＿Ｌ３、Ｈｒｏ＿Ｌ３、Ｈｒｓ＿Ｌ３を収音信号に畳み込む。同様に、音源がＬ２方向である場合、Ｌ２方向を強調するフィルタＨｌｓ＿Ｌ２、Ｈｌｏ＿Ｌ２、Ｈｒｏ＿Ｌ２、Ｈｒｓ＿Ｌ２を収音信号に畳み込む。音源がＬ１方向である場合、Ｌ１方向を強調するフィルタＨｌｓ＿Ｌ１、Ｈｌｏ＿Ｌ１、Ｈｒｏ＿Ｌ１、Ｈｒｓ＿Ｌ１を収音信号に畳み込む。音源がＲ１方向である場合、Ｒ１方向を強調するフィルタＨｌｓ＿Ｒ１、Ｈｌｏ＿Ｒ１、Ｈｒｏ＿Ｒ１、Ｈｒｓ＿Ｒ１を収音信号に畳み込む。音源がＲ２方向である場合、Ｒ２方向を強調するフィルタＨｌｓ＿Ｒ２、Ｈｌｏ＿Ｒ２、Ｈｒｏ＿Ｒ２、Ｈｒｓ＿Ｒ２を収音信号に畳み込む。音源がＲ３方向である場合、Ｒ３方向を強調するフィルタＨｌｓ＿Ｒ３、Ｈｌｏ＿Ｒ３、Ｈｒｏ＿Ｒ３、Ｈｒｓ＿Ｒ３とする。 Specifically, when the sound source is in the L3 direction, filters Hls_L3, Hlo_L3, Hro_L3, and Hrs_L3 that emphasize the L3 direction are convoluted with the collected sound signal. Similarly, when the sound source is in the L2 direction, filters Hls_L2, Hlo_L2, Hro_L2, and Hrs_L2 that emphasize the L2 direction are convoluted with the collected sound signal. When the sound source is in the L1 direction, filters Hls_L1, Hlo_L1, Hro_L1, and Hrs_L1 that emphasize the L1 direction are convolved with the collected sound signal. When the sound source is in the R1 direction, filters Hls_R1, Hlo_R1, Hro_R1, and Hrs_R1 that emphasize the R1 direction are convoluted with the collected sound signal. When the sound source is in the R2 direction, filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 that emphasize the R2 direction are convoluted with the collected sound signal. When the sound source is in the R3 direction, the filters Hls_R3, Hlo_R3, Hro_R3, and Hrs_R3 are used to emphasize the R3 direction.
　次に、図１１を用いて、音源方向を特定するための処理について説明する。図１１は、音源方向を特定するための処理を示すフローチャートである。非定常音検出部１０６が、一定時間毎に、指向性マイク１０１が収音信号を周波数領域に変換する（Ｓ２１）。なお、非定常音検出部１０６は、複数の指向性マイク１０１が取得した収音信号をそれぞれ周波数領域に変換している。ここでは、頭外定位処理部１０２でフィルタが畳み込まれる前の収音信号が周波数領域に変換されている。 Next, processing for specifying the sound source direction will be described with reference to FIG. FIG. 11 is a flowchart showing a process for specifying the sound source direction. The non-stationary sound detection unit 106 converts the collected sound signal into the frequency domain at regular time intervals (S21). Note that the unsteady sound detection unit 106 converts the collected sound signals acquired by the plurality of directional microphones 101 into the frequency domain. Here, the collected sound signal before the filter is convoluted by the out-of-head localization processing unit 102 is converted into the frequency domain.
　次に、非定常音検出部１０６は、スペクトルの一部が大きく変化したか否かを判定する（Ｓ２２）。スペクトルの一部が大きく変化していない場合（Ｓ２２のＮＯ）、ステップＳ２１に戻る。スペクトルの一部が大きく変化した場合（Ｓ２２のＹＥＳ）、非定常音と判定する（Ｓ２３）。 Next, the unsteady sound detection unit 106 determines whether or not a part of the spectrum has changed significantly (S22). If a part of the spectrum has not changed significantly (NO in S22), the process returns to step S21. When a part of the spectrum changes greatly (YES in S22), it is determined as an unsteady sound (S23).
　次に、非定常音検出部１０６は、左の指向性マイク１０１Ｌの音量と右の指向性マイク１０１Ｒの音量の差分Ｍを求める（Ｓ２４）。非定常音検出部１０６は、指向性マイク１０１Ｌの収音信号のスペクトルと、指向性マイク１０１Ｒの収音信号のスペクトルの差分Ｍを求める。ここで、差分を求める周波数帯は特に限定されるものではない。例えば、スペクトルが大きく変化したピーク周波数のみの差分を算出してもよく、スペクトル全体の差分を算出してもよい。あるいは、非定常音検出部１０６は時間領域における左右の収音信号の差分を求めてもよい。 Next, the unsteady sound detection unit 106 obtains a difference M between the volume of the left directional microphone 101L and the volume of the right directional microphone 101R (S24). The unsteady sound detection unit 106 obtains a difference M between the spectrum of the collected sound signal of the directional microphone 101L and the spectrum of the collected sound signal of the directional microphone 101R. Here, the frequency band for obtaining the difference is not particularly limited. For example, the difference of only the peak frequency at which the spectrum has changed greatly may be calculated, or the difference of the entire spectrum may be calculated. Alternatively, the unsteady sound detection unit 106 may obtain the difference between the left and right collected sound signals in the time domain.
　そして、非定常音検出部１０６は、差分Ｍの値に応じて音源方向を特定する。例えば、差分Ｍが＋６ｄＢ以上である場合、非定常音検出部１０６はＬ３方向に音源があると判定する（Ｓ２５）。すなわち、指向性マイク１０１Ｌの音量が指向性マイク１０１Ｒの音量に比べてかなり大きい場合、非定常音検出部１０６は、非定常音の音源がＬ３方向にあると判定する。 And the unsteady sound detection unit 106 specifies the sound source direction according to the value of the difference M. For example, when the difference M is +6 dB or more, the unsteady sound detection unit 106 determines that there is a sound source in the L3 direction (S25). That is, when the volume of the directional microphone 101L is considerably larger than the volume of the directional microphone 101R, the unsteady sound detection unit 106 determines that the unsteady sound source is in the L3 direction.
　差分Ｍが＋３ｄＢ以上、＋６ｄＢ未満である場合、非定常音検出部１０６はＬ２方向に音源があると判定する（Ｓ２６）。差分Ｍが０ｄＢ以上、＋３ｄＢ未満である場合、非定常音検出部１０６はＬ１方向に音源があると判定する（Ｓ２７）。差分Ｍが－３ｄＢ以上、０ｄＢ未満である場合、非定常音検出部１０６はＲ１方向に音源があると判定する（Ｓ２８）。差分Ｍが－６ｄＢ以上、－３ｄＢ未満である場合、非定常音検出部１０６はＲ２方向に音源があると判定する（Ｓ２９）。差分Ｍが－６ｄＢ未満である場合、非定常音検出部１０６はＲ３方向に音源があると判定する（Ｓ３０）。 If the difference M is +3 dB or more and less than +6 dB, the unsteady sound detection unit 106 determines that there is a sound source in the L2 direction (S26). When the difference M is 0 dB or more and less than +3 dB, the unsteady sound detection unit 106 determines that there is a sound source in the L1 direction (S27). When the difference M is not less than −3 dB and less than 0 dB, the unsteady sound detection unit 106 determines that there is a sound source in the R1 direction (S28). When the difference M is not less than −6 dB and less than −3 dB, the unsteady sound detection unit 106 determines that there is a sound source in the R2 direction (S29). When the difference M is less than −6 dB, the unsteady sound detection unit 106 determines that there is a sound source in the R3 direction (S30).
　このように、非定常音検出部１０６はマイク音量の差分Ｍに応じて音源方向を特定している。具体的には、差分Ｍが大きいほど、非定常音検出部１０６は、左方向（２７０°）に音源があると判定する。なお、音量差に限らず、左右のマイクで収音した信号の位相差を用いて音源方向を特定してもよい。音量差（または音量比）と位相差とを組み合わせて音源方向を特定してもよい。 In this way, the unsteady sound detection unit 106 specifies the sound source direction according to the difference M in the microphone volume. Specifically, as the difference M is larger, the unsteady sound detection unit 106 determines that there is a sound source in the left direction (270 °). Note that the direction of the sound source may be specified using the phase difference between signals collected by the left and right microphones, not limited to the volume difference. The sound source direction may be specified by combining the volume difference (or volume ratio) and the phase difference.
　次に、音源方向に応じてフィルタを切り替える処理について、図１２を用いて説明する。図１２は、フィルタを切り替える処理を示すフローチャートである。 Next, the process of switching the filter according to the sound source direction will be described with reference to FIG. FIG. 12 is a flowchart illustrating processing for switching filters.
　非定常音を検出していない平常時は、頭外定位処理部１０２が後方正面のフィルタ（Ｈｌｓ、Ｈｌｏ、Ｈｒｏ、Ｈｒｓ）を収音信号に畳み込む（Ｓ４１）。なお、後方正面のフィルタ（Ｈｌｓ、Ｈｌｏ、Ｈｒｏ、Ｈｒｓ）は、図４に示す測定により取得することができる。そして、上記したように、非定常音検出部１０６が非定常音を検出したか否かを判定する（Ｓ４２）。非定常音を検出していない場合（Ｓ４２のＮＯ）、ステップＳ４１に戻る。すなわち、頭外定位処理部１０２が引き続き、後方正面のフィルタ（Ｈｌｓ、Ｈｌｏ、Ｈｒｏ、Ｈｒｓ）を収音信号に畳み込む。 During normal times when no unsteady sound is detected, the out-of-head localization processing unit 102 convolves the rear front filters (Hls, Hlo, Hro, Hrs) with the collected sound signal (S41). In addition, the filter (Hls, Hlo, Hro, Hrs) of the front front can be acquired by the measurement shown in FIG. Then, as described above, it is determined whether or not the unsteady sound detection unit 106 has detected unsteady sound (S42). If an unsteady sound is not detected (NO in S42), the process returns to step S41. That is, the out-of-head localization processing unit 102 continues to convolve the rear front filters (Hls, Hlo, Hro, Hrs) into the collected sound signal.
　非定常音を検出した場合（Ｓ４２のＹＥＳ）、非定常音検出部１０６は、音源方向を判定する（Ｓ４３）。すなわち、図１１に示した処理により音源方向がＬ３～Ｒ３のいずれにあるかを非定常音検出部１０６が判定する。ステップＳ４３は、図１１に示す処理に対応している。 When an unsteady sound is detected (YES in S42), the unsteady sound detection unit 106 determines the sound source direction (S43). That is, the unsteady sound detection unit 106 determines which of the sound source directions is L3 to R3 by the process shown in FIG. Step S43 corresponds to the process shown in FIG.
　音源方向がＬ３方向である場合（Ｓ４３のＬ３方向）、頭外定位処理部１０２は、Ｌ３方向のフィルタＨｌｓ＿Ｌ３、Ｈｌｏ＿Ｌ３、Ｈｒｏ＿Ｌ３、Ｈｒｓ＿Ｌ３を畳み込む（Ｓ４４）。音源方向がＬ２方向である場合（Ｓ４３のＬ２方向）、頭外定位処理部１０２は、Ｌ２方向のフィルタＨｌｓ＿Ｌ２、Ｈｌｏ＿Ｌ２、Ｈｒｏ＿Ｌ２、Ｈｒｓ＿Ｌ２を畳み込む（Ｓ４５）。音源方向がＬ１方向である場合（Ｓ４３のＬ１方向）、頭外定位処理部１０２は、Ｌ１方向のフィルタＨｌｓ＿Ｌ１、Ｈｌｏ＿Ｌ１、Ｈｒｏ＿Ｌ１、Ｈｒｓ＿Ｌ１を畳み込む（Ｓ４６）。 When the sound source direction is the L3 direction (L3 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_L3, Hlo_L3, Hro_L3, and Hrs_L3 in the L3 direction (S44). When the sound source direction is the L2 direction (L2 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_L2, Hlo_L2, Hro_L2, and Hrs_L2 in the L2 direction (S45). When the sound source direction is the L1 direction (L1 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_L1, Hlo_L1, Hro_L1, and Hrs_L1 in the L1 direction (S46).
　音源方向がＲ１方向である場合（Ｓ４３のＲ１方向）、頭外定位処理部１０２は、Ｒ１方向のフィルタＨｌｓ＿Ｒ１、Ｈｌｏ＿Ｒ１、Ｈｒｏ＿Ｒ１、Ｈｒｓ＿Ｒ１を畳み込む（Ｓ４７）。音源方向がＲ２方向である場合（Ｓ４３のＲ２方向）、頭外定位処理部１０２は、Ｒ２方向のフィルタＨｌｓ＿Ｒ２、Ｈｌｏ＿Ｒ２、Ｈｒｏ＿Ｒ２、Ｈｒｓ＿Ｒ２を畳み込む（Ｓ４８）。音源方向がＲ３方向である場合（Ｓ４３のＲ３方向）、頭外定位処理部１０２は、Ｒ３方向のフィルタＨｌｓ＿Ｒ３、Ｈｌｏ＿Ｒ３、Ｈｒｏ＿Ｒ３、Ｈｒｓ＿Ｒ３を畳み込む（Ｓ４９）。 When the sound source direction is the R1 direction (R1 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_R1, Hlo_R1, Hro_R1, and Hrs_R1 in the R1 direction (S47). When the sound source direction is the R2 direction (R2 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction (S48). When the sound source direction is the R3 direction (R3 direction in S43), the out-of-head localization processing unit 102 convolves the filters Hls_R3, Hlo_R3, Hro_R3, and Hrs_R3 in the R3 direction (S49).
　このように、非定常音検出部１０６が非定常音の音源方向を特定する。そして、頭外定位処理部１０２は、方向毎に設定されたフィルタを畳み込む。このようにすることで、収音信号が音源方向に定位されるため、音源方向の非定常音を強調することができる。 Thus, the unsteady sound detection unit 106 identifies the sound source direction of the unsteady sound. Then, the out-of-head localization processing unit 102 convolves the filter set for each direction. By doing so, since the collected sound signal is localized in the sound source direction, it is possible to emphasize the unsteady sound in the sound source direction.
　なお、方向毎にフィルタを生成する方法について、図１３を用いて説明する。図１３は、フィルタを生成するための測定構成を模式的に示す図である。図１３では、後方正面のフィルタＨｌｓ、Ｈｌｏ、Ｈｒｏ、Ｈｒｓと、Ｒ２方向のフィルタＨｌｓ＿Ｒ２、Ｈｌｏ＿Ｒ２、Ｈｒｏ＿Ｒ２、Ｈｒｓ＿Ｒ２と、を生成するための測定構成が示されている。 A method for generating a filter for each direction will be described with reference to FIG. FIG. 13 is a diagram schematically illustrating a measurement configuration for generating a filter. FIG. 13 shows a measurement configuration for generating the filters Hls, Hlo, Hro, and Hrs in the rear front and the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction.
　図１３に示すように、生成するフィルタに応じて、ステレオスピーカ５の設置位置を変えている。例えば、非定常音を検出していない平常時のフィルタＨｌｓ、Ｈｌｏ、Ｈｒｏ、Ｈｒｓを生成する場合、左スピーカ５Ｌと右スピーカ５Ｒとの中間点が１８０°の方向になっている。Ｒ２方向のフィルタＨｌｓ＿Ｒ２、Ｈｌｏ＿Ｒ２、Ｈｒｏ＿Ｒ２、Ｈｒｓ＿Ｒ２を生成する場合、左スピーカ５Ｌと右スピーカ５Ｒとの中間点が１３５°の方向になっている。なお、ここでの角度は、図８で示した角度に対応している。 As shown in FIG. 13, the installation position of the stereo speaker 5 is changed according to the filter to be generated. For example, when generating normal filters Hls, Hlo, Hro, and Hrs that do not detect unsteady sound, the midpoint between the left speaker 5L and the right speaker 5R is in the direction of 180 °. When the filters Hls_R2, Hlo_R2, Hro_R2, and Hrs_R2 in the R2 direction are generated, the midpoint between the left speaker 5L and the right speaker 5R is in the direction of 135 °. Here, the angle corresponds to the angle shown in FIG.
　ステレオスピーカ５の位置を変えて測定を行うことで、方向別のフィルタを生成することができる。すなわち、受聴者１を回転中心として、左スピーカ５Ｌと右スピーカ５ＲをＬ３～Ｒ３方向に対応する角度だけ回転させる。これにより、方向別のフィルタを簡便に生成することができる。 By changing the position of the stereo speaker 5 and performing measurement, a filter for each direction can be generated. That is, the left speaker 5L and the right speaker 5R are rotated by an angle corresponding to the directions L3 to R3 with the listener 1 as the rotation center. Thereby, the filter according to direction can be easily generated.
　なお、上記の説明では、特定する音源方向をＬ３方向～Ｒ３方向の６つに分割したが、分割数は６個に限定されるものではない。音源方向の特定精度に応じて、音源方向を２以上に分割していればよい。例えば、音源方向の特定精度が低い場合、左斜め後方と右斜め後方の２方向にのみ音源方向を特定できればよい。もちろん、音源の特定方向は６以上であってもよく、６未満であってもよい。 In the above description, the specified sound source direction is divided into six directions from the L3 direction to the R3 direction, but the number of divisions is not limited to six. The sound source direction only needs to be divided into two or more according to the accuracy of the sound source direction. For example, when the accuracy of the sound source direction is low, it is sufficient that the sound source direction can be specified only in the two directions of the left diagonal rear and the right diagonal rear. Of course, the specific direction of the sound source may be 6 or more, or may be less than 6.
定位位置の実施例
　なお、上記の説明では収音信号（周囲音）を後方に定位し、再生信号（音楽）を耳元で鳴らす（頭内に定位させる）例について説明したが、定位位置は特に限定されるものではない。以下、定位位置Ａ、Ｂの実施例について、図１４～図１６を用いて説明する。図１４～図１６はそれぞれ実施例１～３にかかる定位位置を示す図である。 Examples of localization positions In the above description, the example in which the sound pickup signal (ambient sound) is localized backward and the reproduction signal (music) is played at the ear (localization in the head) has been described. It is not limited. Examples of the localization positions A and B will be described below with reference to FIGS. 14 to 16 are diagrams showing localization positions according to Examples 1 to 3, respectively.
　図１４に示す実施例１では、再生信号の定位位置ＡがユーザＵの前方となっており、収音信号の定位位置ＢがユーザＵの耳元になっている（頭内に定位している）。この場合、頭外定位処理部１０２が再生信号に対してのみ頭外定位処理を行う。すなわち、頭外定位処理部１０２が再生信号にのみフィルタを畳み込み、収音信号にはフィルタを畳み込まない。このようにすることで、図１４に示すような定位位置Ａ、Ｂを実現することができる。 In Example 1 shown in FIG. 14, the localization position A of the reproduction signal is in front of the user U, and the localization position B of the sound pickup signal is in the ear of the user U (localized in the head). . In this case, the out-of-head localization processing unit 102 performs out-of-head localization processing only on the reproduction signal. That is, the out-of-head localization processing unit 102 convolves the filter only with the reproduction signal and does not convolve the filter with the collected sound signal. By doing so, localization positions A and B as shown in FIG. 14 can be realized.
　図１５に示す実施例２では、再生信号の定位位置ＡがユーザＵの前方となっており、収音信号の定位位置ＢがユーザＵの後方になっている。この場合、頭外定位処理部１０２が再生信号、及び収音信号の両方に対して頭外定位処理を行う。すなわち、頭外定位処理部１０２が再生信号に前方定位用のフィルタを畳み込み、収音信号には後方定位用のフィルタを畳み込む。このようにすることで、図１５に示すような定位位置Ａ、Ｂを実現することができる。なお、前方定位用のフィルタは、ステレオスピーカ５を受聴者１の前方に設置した測定に基づいて生成される。 15, the localization position A of the reproduction signal is in front of the user U, and the localization position B of the collected sound signal is in the rear of the user U. In this case, the out-of-head localization processing unit 102 performs out-of-head localization processing on both the reproduction signal and the collected sound signal. That is, the out-of-head localization processing unit 102 convolves a reproduced signal with a front localization filter, and convolves a sound localization signal with a rear localization filter. By doing so, localization positions A and B as shown in FIG. 15 can be realized. The front localization filter is generated based on a measurement in which the stereo speaker 5 is installed in front of the listener 1.
　図１６に示す実施例３では、再生信号の定位位置ＡがユーザＵの前方となっている。そして、非定常音の有無に応じて、収音信号の定位位置Ｂが変化している。非定常音が検出されていない場合、収音信号の定位位置Ｂが耳元になっている（頭内に定位している）。非定常音が検出された場合、収音信号の定位位置Ｂ’が後方になっている。すなわち、非定常音に応じて、フィルタを切り替えることで、収音信号の定位位置Ｂを変えている。このようにすることで、図１６に示すような定位位置Ａ、Ｂを実現することができる。 In Example 3 shown in FIG. 16, the localization position A of the reproduction signal is in front of the user U. Then, the localization position B of the collected sound signal changes depending on the presence or absence of the unsteady sound. When an unsteady sound is not detected, the localization position B of the collected sound signal is near the ear (localized in the head). When an unsteady sound is detected, the localization position B ′ of the collected sound signal is rearward. That is, the localization position B of the collected sound signal is changed by switching the filter according to the unsteady sound. By doing so, the localization positions A and B as shown in FIG. 16 can be realized.
　もちろん、再生信号の定位位置Ａと収音信号の定位位置Ｂは上記したものに限定されるものではない。適切なフィルタを用いることで、任意の位置に定位させることができる。再生信号のみフィルタ処理を行ってもよく、収音信号のみフィルタ処理を行ってもよい。あるいは、再生信号と収音信号の両方にフィルタ処理を行ってもよい。また、非定常音の有無に応じて、頭外定位処理部１０２が再生信号の定位位置Ａを切り替えてもよい。さらに、非定常音の有無に応じて、頭外定位処理部１０２が再生信号の定位位置Ａ、及び収音信号の定位位置Ｂの両方を切り替えてもよい。 Of course, the localization position A of the reproduction signal and the localization position B of the sound pickup signal are not limited to those described above. By using an appropriate filter, it can be localized at an arbitrary position. Only the reproduction signal may be filtered, or only the collected sound signal may be filtered. Alternatively, filter processing may be performed on both the reproduction signal and the collected sound signal. Further, the out-of-head localization processing unit 102 may switch the localization position A of the reproduction signal according to the presence or absence of an unsteady sound. Furthermore, the out-of-head localization processing unit 102 may switch both the localization position A of the reproduction signal and the localization position B of the collected sound signal in accordance with the presence or absence of an unsteady sound.
　なお、上記の説明では、合成信号を出力する出力部をイヤホン１０５として説明したが、出力部はヘッドホンであってもよい。また、再生信号により再生される音は音楽プレーヤ１０３から出力される音楽として説明したが、動画と共に再生される再生音であってもよい。例えば、合成部１０４で収音信号に合成される再生信号は、映画の音声などに基づく再生信号であってもよい。さらに、マイクの数は３以上であってもよい。周囲音を収音するマイクは、指向性マイクに限られるものではない。例えば、音楽プレーヤ１０３としてスマートフォンのアプリを用いた場合、スマートフォンのマイクを用いて、周囲音を収音してもよい。 In the above description, the output unit that outputs the synthesized signal is described as the earphone 105, but the output unit may be a headphone. Moreover, although the sound reproduced by the reproduction signal has been described as music output from the music player 103, it may be a reproduction sound reproduced together with a moving image. For example, the reproduction signal combined with the collected sound signal by the synthesis unit 104 may be a reproduction signal based on movie sound or the like. Further, the number of microphones may be three or more. A microphone that collects ambient sounds is not limited to a directional microphone. For example, when a smartphone application is used as the music player 103, ambient sounds may be collected using a smartphone microphone.
　さらに、上記の処理は、スマートフォンなどの携帯端末で実行されてもよく、イヤホンやヘッドホンに内蔵されたＤＳＰ(Digital Signal Processor)等で実行されてもよい。もちろん、上記の処理に一部が携帯端末で実行され、残りがイヤホンやヘッドホンに内蔵されたＤＳＰで実行させてもよい。スマートフォンなどの携帯端末が頭外定位処理を行う場合、指向性マイク１０１が携帯端末の音声入力端子に接続される。 Further, the above processing may be executed by a mobile terminal such as a smartphone, or may be executed by an earphone or a DSP (Digital Signal Processor) built in the headphones. Of course, a part of the above processing may be executed by the mobile terminal, and the rest may be executed by the DSP built in the earphone or the headphone. When a portable terminal such as a smartphone performs out-of-head localization processing, the directional microphone 101 is connected to the voice input terminal of the portable terminal.
　上記信号処理のうちの一部又は全部は、コンピュータプログラムによって実行されてもよい。上述したプログラムは、様々なタイプの非一時的なコンピュータ可読媒体（ｎｏｎ－ｔｒａｎｓｉｔｏｒｙ　ｃｏｍｐｕｔｅｒ　ｒｅａｄａｂｌｅ　ｍｅｄｉｕｍ）を用いて格納され、コンピュータに供給することができる。非一時的なコンピュータ可読媒体は、様々なタイプの実体のある記録媒体（ｔａｎｇｉｂｌｅ　ｓｔｏｒａｇｅ　ｍｅｄｉｕｍ）を含む。非一時的なコンピュータ可読媒体の例は、磁気記録媒体（例えばフレキシブルディスク、磁気テープ、ハードディスクドライブ）、光磁気記録媒体（例えば光磁気ディスク）、ＣＤ－ＲＯＭ（Ｒｅａｄ　Ｏｎｌｙ　Ｍｅｍｏｒｙ）、ＣＤ－Ｒ、ＣＤ－Ｒ／Ｗ、半導体メモリ（例えば、マスクＲＯＭ、ＰＲＯＭ（Ｐｒｏｇｒａｍｍａｂｌｅ　ＲＯＭ)、ＥＰＲＯＭ（Ｅｒａｓａｂｌｅ　ＰＲＯＭ)、フラッシュＲＯＭ、ＲＡＭ（Ｒａｎｄｏｍ　Ａｃｃｅｓｓ　Ｍｅｍｏｒｙ））を含む。また、プログラムは、様々なタイプの一時的なコンピュータ可読媒体（ｔｒａｎｓｉｔｏｒｙ　ｃｏｍｐｕｔｅｒ　ｒｅａｄａｂｌｅ　ｍｅｄｉｕｍ)によってコンピュータに供給されてもよい。一時的なコンピュータ可読媒体の例は、電気信号、光信号、及び電磁波を含む。一時的なコンピュータ可読媒体は、電線及び光ファイバ等の有線通信路、又は無線通信路を介して、プログラムをコンピュータに供給できる。 Some or all of the above signal processing may be executed by a computer program. The programs described above can be stored using various types of non-transitory computer readable media and supplied to a computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). In addition, the program may be supplied to a computer by various types of temporary computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.
　以上、本発明者によってなされた発明を実施の形態に基づき具体的に説明したが、本発明は上記実施の形態に限られたものではなく、その要旨を逸脱しない範囲で種々変更可能であることは言うまでもない。 As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.
　この出願は、２０１６年３月２４日に出願された日本出願特願２０１６－０５９７５５を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2016-059755 filed on Mar. 24, 2016, the entire disclosure of which is incorporated herein.
　本願は、頭外定位処理を行う再生装置に適用可能である。 This application is applicable to a playback device that performs out-of-head localization processing.
　Ｕ　ユーザ
　１　受聴者
　２Ｌ　左マイク
　２Ｒ　右マイク
　５Ｌ　左スピーカ
　５Ｒ　右スピーカ
　９Ｌ　左耳
　９Ｒ　右耳
　１０１　指向性マイク
　１０１Ｌ　左の指向性マイク
　１０１Ｒ　右の指向性マイク
　１０２　頭外定位処理部
　１０３　音楽プレーヤ
　１０４　合成部
　１０５　イヤホン
　１０５Ｌ　左出力ユニット
　１０５Ｒ　右出力ユニット
　１０６　非定常音検出部
　１１０　ネックバンド
　 U user 1 listener 2L left microphone 2R right microphone 5L left speaker 5R right speaker 9L left ear 9R right ear 101 directional microphone 101L left directional microphone 101R right directional microphone 102 out-of-head localization processing unit 103 music player 104 synthesis Part 105 Earphone 105L Left output unit 105R Right output unit 106 Unsteady sound detection part 110 Neckband

Claims (6)

  1. 　再生音を再生するための再生信号を出力する再生部と、
    　ユーザの左右の耳に向けて音をそれぞれ出力する左右の出力ユニットを有する出力部と、
    　周囲音を収音して、収音信号を取得する１つ以上のマイクと、
    　前記収音信号及び前記再生信号の少なくとも一方に対して頭外定位処理を行うことで、前記出力部から出力される際の前記収音信号の定位位置と前記再生信号の定位位置とを異ならせる定位処理部と、
    　前記収音信号と前記再生信号とを合成して、前記出力部に出力する合成部と、を備えた再生装置。     A playback unit that outputs a playback signal for playing back the playback sound;
    An output unit having left and right output units that respectively output sound toward the left and right ears of the user;
    One or more microphones that pick up ambient sound and obtain a picked up signal;
    By performing out-of-head localization processing on at least one of the sound pickup signal and the reproduction signal, the localization position of the sound collection signal and the localization position of the reproduction signal when output from the output unit are made different. A localization processing unit;
    A reproduction apparatus comprising: a synthesis unit that synthesizes the collected sound signal and the reproduction signal and outputs the synthesized signal to the output unit.
  2. 　前記定位処理部は、前記収音信号をユーザの後方に定位させる請求項１に記載の再生装置。 The playback apparatus according to claim 1, wherein the localization processing unit localizes the sound pickup signal to the rear of the user.
  3. 　前記マイクが前記ユーザの後方の音を収音する指向性マイクである請求項１、又は２に記載の再生装置。 The playback apparatus according to claim 1 or 2, wherein the microphone is a directional microphone that collects sound behind the user.
  4. 　前記収音信号に、非定常音が含まれるか否かを検出する非定常音検出部をさらに備え、
    　前記非定常音検出部が、前記非定常音を検出した場合に、前記再生信号に対する前記収音信号の相対的な音量レベルを変化させる請求項１～３のいずれか１項に記載の再生装置。     The sound collection signal further comprises an unsteady sound detection unit for detecting whether or not unsteady sound is included,
    The reproduction apparatus according to any one of claims 1 to 3, wherein the non-stationary sound detection unit changes a relative volume level of the collected sound signal with respect to the reproduction signal when the unsteady sound is detected. .
  5. 　前記マイクが２つ以上設けられ、
    　前記２つ以上のマイクが収音した収音信号に基づいて、前記収音信号に含まれる非定常音の音源方向を特定し、
    　前記非定常音の音源方向に基づいて、前記収音信号の定位位置を変化させる請求項１～４のいずれか１項に記載の再生装置。     Two or more microphones are provided,
    Based on the collected sound signals collected by the two or more microphones, specify the direction of the sound source of the unsteady sound included in the collected sound signal,
    The reproduction apparatus according to any one of claims 1 to 4, wherein a localization position of the collected sound signal is changed based on a sound source direction of the unsteady sound.
  6. 　再生音を再生するための再生信号を出力するステップと、
    　１つ以上のマイクを用いて周囲音を収音して、収音信号を取得するステップと、
    　前記収音信号及び前記再生信号の少なくとも一方に対して定位処理を行うステップと、
    　前記定位処理を行った後、前記収音信号と前記再生信号とを合成して、合成信号を生成するステップと、
    　左右の出力ユニットを有する出力部から、ユーザの左右の耳に向けて、前記合成信号をそれぞれ出力するステップと、を備えた再生方法。     Outputting a reproduction signal for reproducing the reproduction sound;
    Collecting ambient sounds using one or more microphones to obtain a collected signal;
    Performing localization processing on at least one of the collected sound signal and the reproduction signal;
    After performing the localization processing, synthesizing the sound pickup signal and the reproduction signal to generate a synthesized signal;
    A step of outputting the synthesized signal from an output unit having left and right output units toward the left and right ears of the user, respectively.
PCT/JP2017/001957 2016-03-24 2017-01-20 Playback apparatus and playback method WO2017163572A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022009722A1 (en) * 2020-07-09 2022-01-13 ソニーグループ株式会社 Acoustic output device and control method for acoustic output device

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* Cited by examiner, † Cited by third party
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CN111933184B (en) * 2020-09-29 2021-01-08 平安科技（深圳）有限公司 Voice signal processing method and device, electronic equipment and storage medium

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007036610A (en) * 2005-07-26 2007-02-08 Yamaha Corp Sound production device
JP2013162332A (en) * 2012-02-06 2013-08-19 Nippon Sharyo Seizo Kaisha Ltd Headphone
JP2015198297A (en) * 2014-03-31 2015-11-09 株式会社東芝 Acoustic controller, electronic apparatus and acoustic control method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007036610A (en) * 2005-07-26 2007-02-08 Yamaha Corp Sound production device
JP2013162332A (en) * 2012-02-06 2013-08-19 Nippon Sharyo Seizo Kaisha Ltd Headphone
JP2015198297A (en) * 2014-03-31 2015-11-09 株式会社東芝 Acoustic controller, electronic apparatus and acoustic control method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022009722A1 (en) * 2020-07-09 2022-01-13 ソニーグループ株式会社 Acoustic output device and control method for acoustic output device

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