JP6081854B2 - Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug - Google Patents
Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug Download PDFInfo
- Publication number
- JP6081854B2 JP6081854B2 JP2013091828A JP2013091828A JP6081854B2 JP 6081854 B2 JP6081854 B2 JP 6081854B2 JP 2013091828 A JP2013091828 A JP 2013091828A JP 2013091828 A JP2013091828 A JP 2013091828A JP 6081854 B2 JP6081854 B2 JP 6081854B2
- Authority
- JP
- Japan
- Prior art keywords
- signal
- unit
- sound
- negative feedback
- ear canal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000009467 reduction Effects 0.000 title claims description 52
- 210000000613 ear canal Anatomy 0.000 claims description 91
- 238000012545 processing Methods 0.000 claims description 35
- 230000010355 oscillation Effects 0.000 claims description 25
- 230000005540 biological transmission Effects 0.000 claims description 16
- 238000012937 correction Methods 0.000 claims description 16
- 239000000284 extract Substances 0.000 claims description 6
- 230000001902 propagating effect Effects 0.000 claims description 4
- 238000012546 transfer Methods 0.000 description 17
- 230000006870 function Effects 0.000 description 14
- 230000003321 amplification Effects 0.000 description 13
- 238000003199 nucleic acid amplification method Methods 0.000 description 13
- 230000008859 change Effects 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- 238000000034 method Methods 0.000 description 10
- 230000002093 peripheral effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 230000018984 mastication Effects 0.000 description 3
- 238000010077 mastication Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 230000005520 electrodynamics Effects 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 210000003454 tympanic membrane Anatomy 0.000 description 2
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- MOVRNJGDXREIBM-UHFFFAOYSA-N aid-1 Chemical compound O=C1NC(=O)C(C)=CN1C1OC(COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C(NC(=O)C(C)=C2)=O)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C(NC(=O)C(C)=C2)=O)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C(NC(=O)C(C)=C2)=O)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)COP(O)(=O)OC2C(OC(C2)N2C3=C(C(NC(N)=N3)=O)N=C2)CO)C(O)C1 MOVRNJGDXREIBM-UHFFFAOYSA-N 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 210000003128 head Anatomy 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 210000000214 mouth Anatomy 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
Landscapes
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Otolaryngology (AREA)
- Headphones And Earphones (AREA)
- Signal Processing (AREA)
- General Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Psychology (AREA)
- Biophysics (AREA)
- Heart & Thoracic Surgery (AREA)
- Vascular Medicine (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Neurosurgery (AREA)
Description
本発明は、外耳道の密閉によるこもり感や圧迫感などを低減するこもり音低減装置と、このこもり音低減装置を備えた補聴器、オーディオ用イヤホン、耳せんに関する。 The present invention relates to a humming sound reduction device that reduces a feeling of squeezing or a feeling of pressure due to sealing of the ear canal, and a hearing aid, an audio earphone, and an earplug provided with the squeaking noise reduction device.
一般に、耳あな型補聴器や耳せんなどは、外耳道を密閉した状態で装着されるため、音が外耳道から外部の空間に放射されない構造となっている。そのため、補聴器等の使用者の自声の響き音や咀嚼音などにより、使用者にとって不快なこもり感や圧迫感を与えることが問題となる。ここで、上述の構造を有する補聴器等においては、こもり感や圧迫感などの要因となる外耳道内の自声の響き音や咀嚼音など（以下、「こもり音」と呼ぶ）は、主に約１ｋＨｚ以下の低域周波数成分からなる。従来から、この種のこもり音に起因するこもり感や圧迫感を解消する対策が提案されている（特許文献１〜５参照）。 In general, ear-analyzed hearing aids and earplugs are worn with the ear canal sealed, so that sound is not emitted from the ear canal to the external space. For this reason, there is a problem of giving a feeling of being uncomfortable to the user or a feeling of pressure by the sound of the user's own voice such as a hearing aid or a mastication sound. Here, in the hearing aid having the above-described structure, the sound of the voice in the ear canal, the mastication sound, and the like (hereinafter referred to as “boom sounds”), which are factors such as a feeling of being crowded and feeling of pressure, are mainly about. It consists of low frequency components of 1 kHz or less. Conventionally, measures have been proposed to eliminate the feeling of humping and the feeling of pressure caused by this kind of booming sound (see Patent Documents 1 to 5).
上記従来の対策としては、例えば、特許文献１に開示されているように、外耳道と外部を連通するベントを形成し、このベントを通して外耳道内のこもり音をベントを通して放出する手法や、例えば、特許文献２、３、４に開示されているように、外耳道内の音を電気信号に変換する外耳道用マイクロホンを設け、この外耳道用マイクロホンの出力信号に基づいて、こもり音を打ち消す手法や、例えば、特許文献５に開示されているように、上記の外耳道用マイクロホンを設け、この外耳道用マイクロホンの出力信号を用いて負帰還をかける負帰還回路を設ける手法が知られている。 As the above conventional measures, for example, as disclosed in Patent Document 1, a vent that communicates with the external auditory canal and the outside is formed, and a booming sound in the external auditory canal is released through the vent, for example, a patent. As disclosed in Documents 2, 3, and 4, there is provided a microphone for an external auditory canal that converts sound in the ear canal into an electrical signal, and a method for canceling the muffled sound based on the output signal of the microphone for the external auditory canal, for example, As disclosed in Patent Document 5, there is known a method of providing the above-described external ear canal microphone and providing a negative feedback circuit for applying negative feedback using an output signal of the external ear canal microphone.
しかしながら、ベントを設ける手法を採用する場合、ハウリングを防止するためにゲインや出力音圧を制限しなくてはならないため、使用者が聴こえやすい程度の十分な音圧を得ることが難しい場合がある。また、外耳道用マイクロホンの出力信号に基づき、こもり音を打ち消す手法を採用する場合、こもり音を打ち消す信号を生成するための高度な信号処理技術が必要となり、構成の複雑化と消費電力の増加が避けられない。さらに、外耳道用マイクロホンの出力信号に基づき、外耳道用マイクロホンと負帰還回路を設ける手法を採用する場合、構成は簡素化できるものの、負帰還ループにおいてイヤホン（本願発明のレシーバに相当）から外耳道内を伝搬する音の経路を経て外耳道用マイクロホンに至る伝達特性が介在することになり、その伝達特性（レシーバ・外耳道内の音・外耳道用マイクロホンの経路の伝達特性において、レシーバの伝達特性の影響が大きい。）を反映して負帰還信号の周波数成分（例えば、５０Ｈｚ以下及び３ｋＨｚ以上）で位相の変化が大きくなり発振するという問題がある。このように、従来の補聴器等によれば、比較的簡素な構成で、外耳道内の密閉時のこもり音を有効に低減する手法は提案されていなかった。 However, when a method of providing a vent is employed, it may be difficult to obtain sufficient sound pressure that is easy for the user to hear because the gain and output sound pressure must be limited to prevent howling. . In addition, when adopting a method that cancels the muffler sound based on the output signal of the microphone for the external auditory canal, it requires advanced signal processing technology to generate a signal that cancels the muffler sound, resulting in a complicated configuration and an increase in power consumption. Unavoidable. Furthermore, when a method of providing an external ear canal microphone and a negative feedback circuit based on the output signal of the external ear canal microphone is adopted, the configuration can be simplified, but the earphone (corresponding to the receiver of the present invention) can be passed through the ear canal in a negative feedback loop. The transfer characteristic that reaches the microphone for the ear canal via the path of the propagating sound is interposed, and the transfer characteristic (the sound in the receiver and the ear canal and the transfer characteristic of the microphone path for the ear canal has a large influence on the transfer characteristic of the receiver. .) Is reflected, there is a problem that the phase change becomes large and oscillates at the frequency component of the negative feedback signal (for example, 50 Hz or less and 3 kHz or more). Thus, according to a conventional hearing aid or the like, a method for effectively reducing the muffled sound during sealing in the ear canal with a relatively simple configuration has not been proposed.
本発明はこれらの問題を解決するためになされたものであり、外耳道用マイクロホンと負帰還部を用いる構成で問題となる発振を有効に防止しつつ、使用者にとって不快な外耳道内のこもり音を十分に低減し得るこもり音低減装置等を提供することを目的とする。 The present invention has been made to solve these problems, and effectively prevents oscillation that is a problem in the configuration using the ear canal microphone and the negative feedback section, while preventing the user from unpleasantly picking up the noise in the ear canal. An object of the present invention is to provide a booming noise reduction device that can be sufficiently reduced.
上記課題を解決するために、本発明のこもり音低減装置は、伝送経路を介して入力される電気信号を音に変換して外耳道内の空間に出力するレシーバ（４）と、前記外耳道内を伝搬する音を電気信号に変換して負帰還経路に出力する外耳道用マイクロホン（５）と、前記負帰還経路は電気信号のうち所定の低域周波数成分を前記伝送経路に負帰還させる負帰還部（４０、４１）と、前記レシーバの入力側から前記外耳道用マイクロホンの出力側までを電気的に接続する信号バイパス部（４２）とを備えて構成され、前記信号バイパス部は、前記伝送経路の電気信号のうち、少なくとも所定の周波数成分を所定のゲインで増幅し、前記負帰還経路に伝送することを特徴とする。 In order to solve the above-mentioned problems, a noise reduction apparatus according to the present invention includes a receiver (4) that converts an electric signal input via a transmission path into sound and outputs the sound to a space in the ear canal, and the inside of the ear canal. An ear canal microphone (5) that converts a propagating sound into an electrical signal and outputs it to a negative feedback path, and the negative feedback path is a negative feedback section that negatively feeds back a predetermined low frequency component of the electrical signal to the transmission path. (40, 41) and a signal bypass unit (42) for electrically connecting the input side of the receiver to the output side of the ear canal microphone, and the signal bypass unit is connected to the transmission path. Of the electrical signal, at least a predetermined frequency component is amplified with a predetermined gain and transmitted to the negative feedback path.
本発明のこもり音低減装置によれば、外耳道内の密閉時に伝搬するこもり音への対策のため、外耳道用マイクロホンから、負帰還経路、伝送経路、レシーバを経由して外耳道内に至る負帰還ループが構成されるとともに、この負帰還ループに対し、レシーバの入力側から外耳道用マイクロホンの出力側に至る信号バイパス部が構成される。従って、こもり音の低域周波数成分を負帰還によって減衰させるとともに、外耳道内を音が伝搬する経路の伝達特性に起因する位相の変化の影響を、電気的な経路である信号バイパス部によって抑制することができる。よって、発振を生じやすい所定の周波数成分を、信号バイパス部を介してバイパスさせることで、その周波数成分の発振を防止し、十分な負帰還量を確保して、こもり音を確実に低減することができる。 According to the present invention, the negative feedback loop from the ear canal microphone through the negative feedback path, the transmission path, and the receiver into the external ear canal in order to prevent the noise from propagating when sealed in the ear canal. In addition, a signal bypass unit extending from the input side of the receiver to the output side of the ear canal microphone is configured for the negative feedback loop. Therefore, the low frequency component of the muffled sound is attenuated by negative feedback, and the influence of the phase change caused by the transfer characteristic of the path through which the sound propagates in the ear canal is suppressed by the signal bypass unit which is an electrical path. be able to. Therefore, by bypassing the predetermined frequency component that is likely to cause oscillation through the signal bypass unit, oscillation of the frequency component is prevented, and a sufficient amount of negative feedback is ensured to reliably reduce the noise. Can do.
本発明の負帰還部として、例えば、負帰還経路の電気信号を増幅するとともに、負帰還経路の電気信号から低域周波数成分（例、１ｋＨｚ以下）を抽出し、得られた信号の極性を反転させる低域反転増幅部を含む構成を採用することができる。 For example, the negative feedback section of the present invention amplifies the electrical signal in the negative feedback path, extracts a low frequency component (eg, 1 kHz or less) from the electrical signal in the negative feedback path, and inverts the polarity of the obtained signal. It is possible to employ a configuration including a low-frequency inversion amplification unit.
本発明の信号バイパス部は、多様な構成で実現することができる。例えば、信号バイパス部には、低域周波数の発振を抑制する第１のバイパス部を含めることができる。また例えば、信号バイパス部には、高域周波数の発振を抑制する第２のバイパス部を更に含め、第１のバイパス部と第２のバイパス部を並列に接続することができる。この場合、第１のバイパス部を、伝送経路の電気信号を増幅する第１のアンプにより構成するとともに、第２のバイパス部を、伝送経路の電気信号を増幅する第２のアンプと、伝送経路の電気信号から所定の高域周波数成分を抽出するハイパスフィルタとにより構成することができる。この構成により、負帰還ループにおいては、こもり音を含む周波数成分の負帰還量を増加し、こもり音を十分に低減させることができる。 The signal bypass unit of the present invention can be realized in various configurations. For example, the signal bypass unit can include a first bypass unit that suppresses low-frequency oscillation. In addition, for example, the signal bypass unit may further include a second bypass unit that suppresses high-frequency oscillation, and the first bypass unit and the second bypass unit can be connected in parallel. In this case, the first bypass unit is configured by a first amplifier that amplifies the electrical signal of the transmission path, and the second bypass unit is configured by a second amplifier that amplifies the electrical signal of the transmission path, and the transmission path. And a high-pass filter that extracts a predetermined high-frequency component from the electrical signal. With this configuration, in the negative feedback loop, the negative feedback amount of the frequency component including the booming noise can be increased, and the booming noise can be sufficiently reduced.
また、上記課題を解決するために、本発明の補聴器は、上述のこもり音低減装置と、外部音を電気信号に変換する外部マイクロホンと、前記外部マイクロホンの出力信号に対し補聴処理を施す補聴処理部と、前記補聴処理部の出力信号に対し、前記負帰還部による前記低域周波数成分の減衰分を予め補正する低域補正部とを備えて構成される。また、本発明のオーディオ用イヤホンは、上述のこもり音低減装置と、外部からの入力信号に対し、前記負帰還部による前記低域周波数成分の減衰分を予め補正する低域補正部とを備えて構成される。また、本発明の耳せんは、上述のこもり音低減装置を備えて構成される。これらの補聴器、オーディオ用イヤホン、耳せんのいずれに関しても、上記こもり音低減装置により得られる作用、効果を実現することができる。 In order to solve the above-described problems, the hearing aid of the present invention includes the above-described booming sound reduction device, an external microphone that converts external sound into an electrical signal, and a hearing aid process that performs hearing aid processing on the output signal of the external microphone. And a low-frequency correction unit that corrects in advance the attenuation of the low-frequency component by the negative feedback unit with respect to the output signal of the hearing aid processing unit. An audio earphone according to the present invention includes the above-described booming noise reduction device, and a low-frequency correction unit that corrects in advance the attenuation of the low-frequency component by the negative feedback unit with respect to an input signal from the outside. Configured. Moreover, the earplug of the present invention is configured to include the above-described booming sound reduction device. With respect to any of these hearing aids, audio earphones, and earplugs, it is possible to achieve the actions and effects obtained by the above-described muffled sound reduction device.
以上説明したように、本発明によれば、外耳道用マイクロホンを用いて負帰還をかける手法を前提としつつ、外耳道内を経路とする伝達特性による位相の変化の影響を信号バイパス部によって抑制することで、所定の周波数成分で生じる発振を防止することができる。よって、複雑な構成と消費電力の増加を回避しつつ、負帰還部の負帰還量を増加させて確実にこもり音を低減させ、外耳道を密閉しても使用者にとって不快なこもり感や圧迫感の少ないこもり音低減装置を実現することができる。また、このこもり音低減装置を、補聴器、オーディオ用イヤホン、耳せんに組み込むことにより、これらの機器の使用時において、こもり音を確実に低減して、こもり感などの不快感を低減することができる。 As described above, according to the present invention, the signal bypass unit suppresses the influence of the phase change due to the transfer characteristic in the ear canal while assuming the method of applying negative feedback using the ear canal microphone. Thus, oscillation that occurs at a predetermined frequency component can be prevented. Therefore, while avoiding a complicated configuration and an increase in power consumption, the amount of negative feedback in the negative feedback section is increased to reliably reduce the muffled noise, and the user feels uncomfortable when the ear canal is sealed. Therefore, it is possible to realize a device for reducing the volume of noise. In addition, by incorporating this noise reduction device into hearing aids, audio earphones, and earplugs, it is possible to reliably reduce the volume of noise when using these devices, thereby reducing discomfort such as a feeling of noise. it can.
以下、本発明の実施形態について添付図面を参照しながら説明する。以下の実施形態は、使用者の外耳道内に装着可能な補聴器、耳せん、オーディオ用イヤホンと、これらの機器の主要部であるこもり音低減装置のそれぞれに対し、本発明を適用した例である。
［補聴器］
以下、本発明を適用した補聴器の実施形態を説明する。図１は、本実施形態の補聴器の概略の構成を示すブロック図である。図１に示す補聴器は、使用者の耳に挿入可能な形状を有する筐体としてのケースＣ内に、外部マイクロホン２と、信号処理部３と、レシーバ４と、外耳道用マイクロホン５と、電池ホルダ６及びその内部のボタン電池７とをそれぞれ収容して構成される。ケースＣは、耳の外部空間に面するフェースプレートＣ１と、外耳道１０に沿って配置されるシェルＣ２からなる。フェースプレートＣ１には、外部マイクロホン２が音口などを介して取り付けられ、シェルＣ２のうち外耳道１０の奥の鼓膜１１との間の空間Ｓに面した部分には、レシーバ４と外耳道用マイクロホン５がそれぞれ音口などを介して取り付けられている。
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiments are examples in which the present invention is applied to each of a hearing aid, earplugs, audio earphones that can be mounted in a user's ear canal, and a booming sound reduction device that is a main part of these devices. .
[hearing aid]
Hereinafter, embodiments of a hearing aid to which the present invention is applied will be described. FIG. 1 is a block diagram showing a schematic configuration of a hearing aid according to the present embodiment. The hearing aid shown in FIG. 1 includes an external microphone 2, a signal processing unit 3, a receiver 4, an external ear canal microphone 5, and a battery holder in a case C as a housing having a shape that can be inserted into a user's ear. 6 and the button battery 7 inside thereof are accommodated. The case C includes a face plate C1 facing the external space of the ear and a shell C2 disposed along the ear canal 10. An external microphone 2 is attached to the face plate C1 through a sound outlet, and the receiver 4 and the ear canal microphone 5 are disposed in a portion of the shell C2 facing the space S between the eardrum 11 and the ear canal 10. Are attached via sound openings.
図１の構成において、外部マイクロホン２は、外部空間から伝わる音を収集し、電気信号に変換する。これに対し、外耳道用マイクロホン５は、外耳道１０内の空間Ｓから伝わる音を収集し、電気信号に変換する。外部マイクロホン２及び外耳道マイクロホン５としては、ＭＥＭＳ（Micro Electro Mechanical Systems）、動電型、コンデンサ型、圧電型などの多様なマイクロホンを用いることができる。また、外耳道用マイクロホン５の近傍のレシーバ４は、電気信号を音に変換し、上記の空間Ｓに出力する。レシーバ４としては、動電型や電磁型などのレシーバを用いることができる。信号処理部３は、外部マイクロホン２及び外耳道用マイクロホン５からそれぞれ入力される電気信号と、レシーバ４に出力される電気信号とに対して信号処理を施す。信号処理部３としては、ディジタル信号処理を実行可能なＤＳＰ(Digital Signal Processor)を用いて構成してもよいが、アナログ信号処理を実行可能なアナログ回路を用いて構成してもよい。電池ホルダ６の内部に保持されるボタン電池７は、補聴器の各構成部材に対して電源を供給する。なお、必要に応じて電池ホルダ６の開口部を開閉してボタン電池７の交換が可能に構成されている。 In the configuration of FIG. 1, the external microphone 2 collects sound transmitted from the external space and converts it into an electrical signal. In contrast, the ear canal microphone 5 collects sound transmitted from the space S in the ear canal 10 and converts it into an electrical signal. As the external microphone 2 and the external auditory canal microphone 5, various microphones such as MEMS (Micro Electro Mechanical Systems), electrodynamic type, condenser type, and piezoelectric type can be used. The receiver 4 in the vicinity of the ear canal microphone 5 converts the electrical signal into sound and outputs the sound to the space S. As the receiver 4, an electrodynamic type or electromagnetic type receiver can be used. The signal processing unit 3 performs signal processing on the electrical signal input from the external microphone 2 and the ear canal microphone 5 and the electrical signal output to the receiver 4. The signal processing unit 3 may be configured using a DSP (Digital Signal Processor) capable of executing digital signal processing, but may be configured using an analog circuit capable of executing analog signal processing. A button battery 7 held inside the battery holder 6 supplies power to each component of the hearing aid. The button battery 7 can be replaced by opening and closing the opening of the battery holder 6 as necessary.
上記の構成のうち、外耳道１０内の空間Ｓ側に位置するレシーバ４及び外耳道用マイクロホン５は、信号処理部３の機能に基づいて、外耳道１０内のこもり音を低減するために必要な部品である。すなわち、ケースＣによって外耳道１０の開口が塞がれていると、補聴器の使用者の自声や咀嚼音などが外耳道１０に伝わったときに、その音が大きく聞こえる（こもり音）ため、使用者に不快感（こもり感）を与える恐れがある。そのための対策として、信号処理部３の機能に基づき、こもり音の低減処理を実行するものであるが、詳細については後述する。 Among the above configurations, the receiver 4 and the microphone 5 for the external auditory canal that are located on the space S side in the external auditory canal 10 are components necessary for reducing the loud sound in the external auditory canal 10 based on the function of the signal processing unit 3. is there. That is, if the opening of the external auditory canal 10 is blocked by the case C, when the hearing aid user's own voice or mastication sound is transmitted to the external auditory canal 10, the sound can be heard loudly (humid sound). May cause discomfort (feeling of being full). As a countermeasure for this, the process of reducing the booming noise is executed based on the function of the signal processing unit 3, and details will be described later.
次に図２は、本実施形態の補聴器において、信号処理部３及びその周辺部を含む主要部の構成を示すブロック図である。図２に示すように、信号処理部３の機能要素には、補聴処理部２０と、低域補正部２１と、こもり音低減部２２が含まれる。補聴処理部２０は、外部マイクロホン２の出力信号を入力し、使用者の聴力特性や使用環境に応じて個別に設定された所定の補聴処理を施す手段である。補聴処理部２０によって施される補聴処理としては、例えば、外部マイクロホン２の出力信号に対するマルチバンドコンプレッション、ノイズリダクション、トーンコントロール、ボリュームコントロール、出力制限処理などの多様な処理を適用可能である。 Next, FIG. 2 is a block diagram showing a configuration of a main part including the signal processing unit 3 and its peripheral part in the hearing aid of the present embodiment. As shown in FIG. 2, the functional elements of the signal processing unit 3 include a hearing aid processing unit 20, a low frequency correction unit 21, and a booming sound reduction unit 22. The hearing aid processing unit 20 is a unit that inputs an output signal of the external microphone 2 and performs predetermined hearing aid processing that is individually set in accordance with the hearing characteristics of the user and the usage environment. As the hearing aid processing performed by the hearing aid processing unit 20, various processes such as multiband compression, noise reduction, tone control, volume control, and output restriction processing on the output signal of the external microphone 2 can be applied.
低域補正部２１は、補聴処理後の信号に対し、こもり音低減部２２の後述の動作による低域周波数成分の減衰分を予め補正する手段である。図２の例では、補聴処理部２０の出力信号のうち補正が必要な周波数成分（主に低域周波数）を抽出するフィルタ３０と、フィルタ３０の出力信号を増幅する増幅器３１と、補聴処理部２０の出力信号と増幅器３１の出力信号を加算する加算部３２とにより構成される。なお、低域補正部２１は、図２の構成には限られず、所望の補正を実現し得る多様な構成を適用することができる。 The low-frequency correction unit 21 is a unit that corrects in advance the attenuation of the low-frequency component due to the operation described later of the booming sound reduction unit 22 with respect to the signal after hearing aid processing. In the example of FIG. 2, a filter 30 that extracts a frequency component (mainly a low frequency) that needs correction from the output signal of the hearing aid processor 20, an amplifier 31 that amplifies the output signal of the filter 30, and a hearing aid processor The adder 32 adds the 20 output signals and the output signal of the amplifier 31. Note that the low-frequency correction unit 21 is not limited to the configuration in FIG. 2, and various configurations that can realize a desired correction can be applied.
こもり音低減部２２は、上述したように、外耳道１０内のこもり音を低減する役割があり、低域反転増幅部４０と、加算部４１と、信号バイパス部４２と、加算部４３を備えて構成される。以上の構成において、低域反転増幅部４０は、外耳道用マイクロホン５の出力信号に含まれる低域周波数成分を抽出して所定のゲインで増幅し、その極性を反転して信号−Ｓ１を出力する。加算部４１は、低域補正部２１から出力される入力信号Ｓｉｎと、低域反転増幅部４０から出力される信号−Ｓ１を加算し、出力信号Ｓｏｕｔを生成する。つまり、出力信号Ｓｏｕｔは、次式で表すことができる。 As described above, the muffled sound reduction unit 22 has a role of reducing the muffled sound in the ear canal 10, and includes a low frequency inversion amplification unit 40, an addition unit 41, a signal bypass unit 42, and an addition unit 43. Composed. In the above configuration, the low-frequency inverting amplification unit 40 extracts the low-frequency component contained in the output signal of the ear canal microphone 5, amplifies it with a predetermined gain, inverts its polarity, and outputs the signal -S1. . The adder 41 adds the input signal Sin output from the low-frequency correction unit 21 and the signal −S1 output from the low-frequency inverting amplifier 40 to generate an output signal Sout. That is, the output signal Sout can be expressed by the following equation.
Ｓｏｕｔ＝Ｓｉｎ−Ｓ１
なお、低域反転増幅部４０及び加算部４１は、外耳道用マイクロホン５の出力信号と同じ極性の信号Ｓ１を出力する低域増幅部と、入力信号Ｓｉｎから信号Ｓ１を減算する減算部とで置き換えて考えても同様の機能を実現できる。
Sout = Sin−S1
Note that the low-frequency inverting amplifier 40 and the adder 41 are replaced with a low-frequency amplifier that outputs a signal S1 having the same polarity as the output signal of the ear canal microphone 5, and a subtractor that subtracts the signal S1 from the input signal Sin. The same function can be realized.
上記出力信号Ｓｏｕｔは、加算部４１からレシーバ４の入力側に至る伝送経路を介して伝送され、レシーバ４により音に変換される。この音は、外耳道１０内の空間Ｓを経由して外耳道用マイクロホン５に入力された後、再び電気信号に変換される。そして、この電気信号は外耳道用マイクロホン５の出力側から低域反転増幅部４０に向かう負帰還経路に沿って伝送される。以上のように、低域反転増幅部４０と、加算部４１と、レシーバ４と、外耳道用マイクロホン５は負帰還ループを構成する。このうち、低域反転増幅部４０及び加算部４１は、本発明の負帰還部として機能する。 The output signal Sout is transmitted through a transmission path from the adder 41 to the input side of the receiver 4, and is converted into sound by the receiver 4. This sound is input to the ear canal microphone 5 via the space S in the ear canal 10 and then converted into an electric signal again. The electrical signal is transmitted along a negative feedback path from the output side of the ear canal microphone 5 toward the low-frequency inverting amplifier 40. As described above, the low-frequency inverting amplifier 40, the adder 41, the receiver 4, and the ear canal microphone 5 constitute a negative feedback loop. Among these, the low frequency inverting amplification unit 40 and the addition unit 41 function as a negative feedback unit of the present invention.
一方、信号バイパス部４２は、レシーバ４の入力側（伝送経路）から外耳道用マイクロホン５の出力側（負帰還経路）までを電気的に接続するバイパス回路として機能する。すなわち、上述の出力信号Ｓｏｕｔのうちの所定の周波数成分は、所定のゲインで信号バイパス部４２及び加算部４３を経由して負帰還経路に伝送される。信号バイパス部４２は、レシーバ４から外耳道用マイクロホン５までの伝達特性に応じて、上述の負帰還ループを通る信号の振幅と位相を調整する役割があり、後述するように多様な構成で実現することができる。 On the other hand, the signal bypass unit 42 functions as a bypass circuit that electrically connects the input side (transmission path) of the receiver 4 to the output side (negative feedback path) of the ear canal microphone 5. That is, a predetermined frequency component of the output signal Sout is transmitted to the negative feedback path via the signal bypass unit 42 and the addition unit 43 with a predetermined gain. The signal bypass unit 42 has a role of adjusting the amplitude and phase of the signal passing through the negative feedback loop according to the transfer characteristics from the receiver 4 to the ear canal microphone 5, and can be realized in various configurations as will be described later. be able to.
ここで、図３は、本実施形態におけるこもり音低減部２２の動作との対比のために、図２の信号バイパス部４２を除去したこもり音低減部２２ａの構成を比較例として示している。上述したように、こもり音は主に約１ｋＨｚ以下の周波数成分からなるが、その中でも特に１００〜４００Ｈｚの低域の周波数成分に集中している。よって、低域反転増幅部４０により、こもり音を含む低域の周波数成分を低域反転増幅部４０で抽出して反転増幅すれば、こもり音を含む周波数領域で負帰還ループが構成され、こもり音を低減することができる。しかし、図３の比較例において、負帰還ループに含まれる空間Ｓを経路とする伝達特性により、こもり音より低い周波数成分(５０Ｈｚ以下）及び３ｋＨｚより高い周波数成分の両方で振幅と位相が大きく変化する傾向があることを考慮していない。よって、図３の比較例を採用する場合には、負帰還ループで発振が生じない程度に負帰還量を抑えなければならず、こもり音を十分に低減できないという問題がある。 Here, FIG. 3 shows, as a comparative example, the configuration of the booming noise reduction unit 22a from which the signal bypass unit 42 of FIG. 2 is removed for comparison with the operation of the booming noise reduction unit 22 in the present embodiment. As described above, the muffled sound mainly consists of frequency components of about 1 kHz or less, and among these, it is concentrated particularly in the low frequency components of 100 to 400 Hz. Therefore, if the low frequency inversion amplification unit 40 extracts and inverts the low frequency components including the muffled sound by the low frequency inversion amplification unit 40, a negative feedback loop is formed in the frequency region including the muffled sound. Sound can be reduced. However, in the comparative example of FIG. 3, the amplitude and phase change greatly both in the frequency component lower than the muffled sound (50 Hz or less) and the frequency component higher than 3 kHz due to the transfer characteristic through the space S included in the negative feedback loop. Does not consider that there is a tendency to. Therefore, when the comparative example of FIG. 3 is employed, there is a problem that the amount of negative feedback must be suppressed to such an extent that oscillation does not occur in the negative feedback loop, and the muffled noise cannot be reduced sufficiently.
ここで、負帰還ループでの発振について説明する。例えば、特定の周波数成分に十分な負帰還をかけるとき、位相の変化が９０°を超えると、その周波数成分で発振しやすくなり、さらに位相の変化が１８０°になると負帰還が実質的に正帰還になるので、一層発振の恐れが強くなる。この発振についてナイキスト線図の極座標平面（実部Ｒｅ、虚部Ｉｍ）では、Ｉｍ＝０、Ｒｅの軸上とベクトル軌跡が交差する点において、Ｒｅ＞−１にある場合は発振せずに増幅できるが、Ｒｅ≦−１となる場合は発振することになる。 Here, the oscillation in the negative feedback loop will be described. For example, when sufficient negative feedback is applied to a specific frequency component, if the phase change exceeds 90 °, oscillation tends to occur at that frequency component, and if the phase change reaches 180 °, the negative feedback is substantially positive. Since it becomes a feedback, the risk of oscillation becomes even stronger. In the polar coordinate plane (real part Re, imaginary part Im) of the Nyquist diagram, this oscillation is amplified without oscillation if Im = 0 and the point where the axis of Re intersects the vector locus is Re> -1. However, when Re ≦ −1, oscillation occurs.
これに対し、本実施形態の図２の構成によれば、信号バイパス部４２を設けたため、負帰還ループに対して空間Ｓを経路とする伝達特性の影響を受けない信号を付加することができる。すなわち、図２の出力信号Ｓｏｕｔに対し、信号バイパス部４２により、その回路構成に依存するゲインと位相が与えられた信号が生成され、それが外耳道用マイクロホン５の出力信号に付加される。この場合、信号バイパス部４２は電気的なバイパス経路を構成するので、空間Ｓを経路とする伝達特性に比べて位相変化を十分に抑制することができ、負帰還量を高めても負帰還ループにおける発振を有効に防止しつつ、こもり音を低減することができる。この場合、信号バイパス部４２は比較的簡単な構成で実現できるので、複雑な信号処理や消費電力の増加を回避しつつ、補聴器の性能向上を図ることができる。 On the other hand, according to the configuration of FIG. 2 of the present embodiment, since the signal bypass unit 42 is provided, it is possible to add a signal that is not affected by the transfer characteristic having the space S as a path to the negative feedback loop. . That is, for the output signal Sout in FIG. 2, the signal bypass unit 42 generates a signal to which a gain and a phase depending on the circuit configuration are given, and adds the signal to the output signal of the ear canal microphone 5. In this case, since the signal bypass unit 42 constitutes an electrical bypass path, the phase change can be sufficiently suppressed as compared with the transfer characteristic using the space S as a path, and the negative feedback loop can be increased even if the negative feedback amount is increased. It is possible to reduce the muffled noise while effectively preventing the oscillation at. In this case, since the signal bypass unit 42 can be realized with a relatively simple configuration, the performance of the hearing aid can be improved while avoiding complicated signal processing and an increase in power consumption.
以下、図４及び図５を参照して、信号バイパス部４２の回路構成を含めて、こもり音低減部２２の具体的な構成例について説明する。図４及び図５においては、信号バイパス部４２の構成例に加えて、低域反転増幅部４０の構成例を付加するとともに、レシーバ４の伝達関数Ｒ（ｚ）と、外耳道用マイクロホン５の伝達関数Ｍ（ｚ）と、外耳道１０内の空間Ｓにおけるレシーバ４の出力側から外耳道用マイクロホン５の入力側に至る経路の伝達関数Ｆ（ｚ）をそれぞれ付加している。また、こもり音は、自声が口腔内の音響インピーダンスＺの経路を介して外耳道用マイクロホン５に入力されるものとして表される。 Hereinafter, a specific configuration example of the booming noise reduction unit 22 including the circuit configuration of the signal bypass unit 42 will be described with reference to FIGS. 4 and 5. 4 and 5, in addition to the configuration example of the signal bypass unit 42, the configuration example of the low frequency inversion amplification unit 40 is added, and the transfer function R (z) of the receiver 4 and the transmission of the microphone 5 for the external ear canal A function M (z) and a transfer function F (z) of a path from the output side of the receiver 4 to the input side of the ear canal microphone 5 in the space S in the ear canal 10 are respectively added. Also, the muffled sound is expressed as that the voice is input to the ear canal microphone 5 through the path of the acoustic impedance Z in the oral cavity.
図４は、こもり音低減部２２の第１の構成例を示している。第１の構成例の低域反転増幅部４０は、外耳道用マイクロホン５の出力信号を増幅するアンプＡ０と、アンプＡ０により増幅された信号の高域周波数成分を除去するローパスフィルタＦ０とにより構成される。また、第１の構成例の信号バイパス部４２は、アンプＡ１からなる第１のバイパス部と、アンプＡ２及びハイパスフィルタＦ１からなる第２のバイパス部とを含み、第１及び第２のバイパス部が並列に接続されている。第１のバイパス部は、所定のゲインに設定されたアンプＡ１を介して、出力信号Ｓｏｕｔを低域反転増幅部４０の入力側に導く。第２のバイパス部は、所定のゲインに設定されたアンプＡ２及び低域周波数成分を除去するハイパスフィルタＦ１を介して、出力信号Ｓｏｕｔの低域周波数成分を低域反転増幅部４０の入力側に導く。 FIG. 4 shows a first configuration example of the booming noise reduction unit 22. The low-frequency inverting amplification unit 40 of the first configuration example includes an amplifier A0 that amplifies the output signal of the ear canal microphone 5, and a low-pass filter F0 that removes a high-frequency component of the signal amplified by the amplifier A0. The The signal bypass unit 42 of the first configuration example includes a first bypass unit including the amplifier A1 and a second bypass unit including the amplifier A2 and the high-pass filter F1, and includes the first and second bypass units. Are connected in parallel. The first bypass unit guides the output signal Sout to the input side of the low-frequency inverting amplification unit 40 via the amplifier A1 set to a predetermined gain. The second bypass unit passes the low-frequency component of the output signal Sout to the input side of the low-frequency inverting amplifier 40 via the amplifier A2 set to a predetermined gain and the high-pass filter F1 that removes the low-frequency component. Lead.
図４に示すこもり音低減部２２の動作について説明する。まず、こもり音低減部２２の出力信号Ｓｏｕｔは、レシーバ４により音に変換されて出力され、その音が外耳道１０内の空間Ｓを伝搬して外耳道用マイクロホン５に入力され、外耳道用マイクロホン５により電気信号に変換される。このとき、外耳道用マイクロホン５には、レシーバ４から伝搬する音に加えて、周波数１００〜４００Ｈｚ程度のこもり音も入力される。外耳道用マイクロホン５から出力される信号は、信号バイパス部４２から出力される信号と合成された後、低域反転増幅部４０に入力される。低域反転増幅部４０では、入力信号がアンプＡ０により増幅されるとともに、ローパスフィルタＦ０により低域周波数成分が抽出された後、加算部４１を介して入力信号Ｓｉｎに負帰還される。よって、低域反転増幅部４０は、こもり音に相当する周波数成分の負帰還量が十分に大きくなるような周波数特性が付与される。 The operation of the booming noise reduction unit 22 shown in FIG. 4 will be described. First, the output signal Sout of the muffled sound reduction unit 22 is converted into a sound by the receiver 4 and output. The sound propagates through the space S in the ear canal 10 and is input to the ear canal microphone 5, and is output by the ear canal microphone 5. It is converted into an electrical signal. At this time, in addition to the sound propagated from the receiver 4, a muffled sound having a frequency of about 100 to 400 Hz is also input to the ear canal microphone 5. The signal output from the ear canal microphone 5 is combined with the signal output from the signal bypass unit 42 and then input to the low frequency inversion amplification unit 40. In the low-frequency inverting amplifier 40, the input signal is amplified by the amplifier A0, and a low-frequency component is extracted by the low-pass filter F0, and then negatively fed back to the input signal Sin via the adder 41. Therefore, the low frequency inversion amplifying unit 40 is provided with a frequency characteristic such that the negative feedback amount of the frequency component corresponding to the booming noise is sufficiently large.
上述したように、図４の負帰還ループには、レシーバ４の伝達関数Ｒ（ｚ）と、外耳道１０内の経路の伝達関数Ｆ（ｚ）と、外耳道用マイクロホン５の伝達関数Ｍ（ｚ）が存在する。このうち、特にレシーバ４の伝達関数Ｒ（ｚ）は、所定の周波数成分（例えば、５０Ｈｚ以下及び３ｋＨｚ以上）で位相の変化が増える傾向があるため（ナイキスト線図では、Ｉｍ＝０、Ｒｅの軸上とベクトル軌跡が交差する点において、Ｒｅ≦−１となる傾向にある）、上述のメカニズムにより負帰還ループの発振が生じる恐れがある。信号バイパス部４２を設けて、外耳道１０内を経由しない電気的なバイパス経路を構成し、位相変化の無い信号を外耳道用マイクロホン５からの位相変化の大きい出力信号に加算することで、ナイキスト線図におけるベクトル軌跡をＲｅ軸のプラス方向にずらすことになり、負帰還のゲインを増幅させてもベクトル軌跡がＩｍ＝０、Ｒｅの軸上と交差する点をＲｅ＞−１にすることができる。従って、上述の空間Ｓを経路とする伝達特性による急激な位相変化を十分に抑制し、所定の周波数成分（例えば、５０Ｈｚ以下及び３ｋＨｚ以上）の発振を防止することができる。なお、フィルタＦ１及びアンプＡ１、Ａ２の特性は、負帰還ループの負帰還量と周波数成分（例えば、５０Ｈｚ以下及び３ｋＨｚ以上）の位相変化量に応じて設定することになる。 As described above, the negative feedback loop of FIG. 4 includes the transfer function R (z) of the receiver 4, the transfer function F (z) of the path in the ear canal 10, and the transfer function M (z) of the microphone 5 for the ear canal. Exists. Among these, especially the transfer function R (z) of the receiver 4 tends to increase in phase change at a predetermined frequency component (for example, 50 Hz or less and 3 kHz or more) (In the Nyquist diagram, Im = 0 and Re There is a tendency that Re ≦ −1 at the point where the axis and the vector locus intersect), and the above-described mechanism may cause oscillation of the negative feedback loop. A signal bypass unit 42 is provided to form an electrical bypass path that does not pass through the ear canal 10, and a signal without phase change is added to an output signal having a large phase change from the microphone 5 for the ear canal, thereby providing a Nyquist diagram. Is shifted in the positive direction of the Re axis, and even if the gain of the negative feedback is amplified, the point where the vector locus intersects with Im = 0 and the Re axis can be set to Re> -1. Accordingly, it is possible to sufficiently suppress a sudden phase change due to the transfer characteristic through the above-described space S, and to prevent oscillation of a predetermined frequency component (for example, 50 Hz or less and 3 kHz or more). The characteristics of the filter F1 and the amplifiers A1 and A2 are set according to the negative feedback amount of the negative feedback loop and the phase change amount of the frequency component (for example, 50 Hz or less and 3 kHz or more).
信号バイパス部４２のうち、アンプＡ１からなる第１のバイパス部は、主に５０Ｈｚ以下の周波数成分の発振防止に効果があり、アンプＡ２及びハイパスフィルタＦ１からなる第２のバイパス部は、主に３ｋＨｚ以上の周波数成分の発振防止に効果がある。なお、第１のバイパス部は、アンプＡ１を適正なゲインにした場合、５０Ｈｚ以下の周波数成分に対して有効となり、それより高い音声周波数帯域では外耳道用マイクロホン５の出力信号に対してほとんど影響しない信号レベルなので、ローパスフィルタは省略されているが、アンプＡ１と直列のローパスフィルタを設けてもよい。 Of the signal bypass unit 42, the first bypass unit including the amplifier A1 is mainly effective in preventing oscillation of frequency components of 50 Hz or less, and the second bypass unit including the amplifier A2 and the high-pass filter F1 is mainly used. This is effective in preventing oscillation of frequency components of 3 kHz or higher. The first bypass unit is effective for frequency components of 50 Hz or less when the amplifier A1 is set to an appropriate gain, and hardly affects the output signal of the ear canal microphone 5 in a higher audio frequency band. Since it is a signal level, the low-pass filter is omitted, but a low-pass filter in series with the amplifier A1 may be provided.
次に図５は、こもり音低減部２２の第２の構成例を示している。第２の構成例は、図４と同様の構成の低域反転増幅部４０と、アンプＡ１からなる第１のバイパス部のみを含む信号バイパス部４２とにより構成される。すなわち、図５に示す第２の構成例は、図４に示す第２の構成例の信号バイパス部４２における第２のバイパス部（アンプＡ２及びハイパスフィルタＦ１）を除去したものである。第２の構成例は、こもり音低減部２２において、３ｋＨｚ以上の周波数成分の発振はそれほど問題にならないが、５０Ｈｚ以下の周波数成分の発振対策が必要となる場合、第１の構成例に比べて回路構成を簡素化できるメリットがある。 Next, FIG. 5 shows a second configuration example of the booming noise reduction unit 22. The second configuration example includes a low-frequency inverting amplification unit 40 having the same configuration as that in FIG. 4 and a signal bypass unit 42 including only the first bypass unit including the amplifier A1. That is, the second configuration example shown in FIG. 5 is obtained by removing the second bypass unit (amplifier A2 and high-pass filter F1) in the signal bypass unit 42 of the second configuration example shown in FIG. In the second configuration example, the oscillation of the frequency component of 3 kHz or higher is not so problematic in the booming noise reduction unit 22, but when countermeasures for oscillation of the frequency component of 50 Hz or less are required, compared to the first configuration example. There is an advantage that the circuit configuration can be simplified.
次に、本実施形態のこもり音低減部２２の動作に基づく効果について、図６を参照して説明する。図６は、例えば、自声として「い」と発声としたときの外耳道１０内のこもり音について、こもり音低減部２２の動作の有無に応じた評価結果を比較して示している。具体的には、外耳道１０の開放状態の音圧を基準とし（０ｄＢ）、こもり音低減部２２を動作させることなく外耳道１０を密閉した状態では、音圧レベルが相対的に１０〜２０ｄＢ程度上昇していることが認められる。これに対し、同様の密閉状態でこもり音低減部２２を動作させた場合には、相対音圧レベルが０ｄＢ以下まで低下し、外耳道１０の開放状態を若干下回る程度の音圧になることが認められる。この結果から、こもり音に起因する不快なこもり感や圧迫感を受けない程度の効果が確認できた。これは、既に説明したように、こもり音低減部２２において、信号バイパス部４２の作用で低域及び高域の発振を抑制できるので、こもり音を十分に低減できる程度に負帰還量を高められるために得られる効果である。 Next, effects based on the operation of the booming noise reduction unit 22 of the present embodiment will be described with reference to FIG. FIG. 6 shows, for example, a comparison of evaluation results according to the presence or absence of the operation of the muffled sound reduction unit 22 for the muffled sound in the ear canal 10 when “i” is uttered as the own voice. Specifically, the sound pressure level is relatively increased by about 10 to 20 dB in a state where the ear canal 10 is sealed without operating the muffled sound reduction unit 22 with the sound pressure in the open state of the ear canal 10 as a reference (0 dB). It is recognized that On the other hand, when the booming sound reduction unit 22 is operated in the same sealed state, it is recognized that the relative sound pressure level is reduced to 0 dB or less, and the sound pressure is slightly lower than the open state of the ear canal 10. It is done. From this result, it was confirmed that the effect of not feeling uncomfortable bulkiness and pressure caused by the bulk sound. As described above, in the booming noise reduction unit 22, low-frequency and high-frequency oscillations can be suppressed by the action of the signal bypass unit 42, so that the amount of negative feedback can be increased to the extent that the booming noise can be sufficiently reduced. This is an effect obtained.
［オーディオ用イヤホン］
以下、本発明を適用したオーディオ用イヤホンの実施形態を説明する。本実施形態のオーディオ用イヤホンは、多くの点で上述の補聴器と共通であるため、以下で主に異なる点について説明する。図７は、本実施形態のオーディオ用イヤホン５０において、信号処理部３及びその周辺部を含む主要部の構成を示すブロック図である。図７には、オーディオ用イヤホン本体（不図示）に内蔵される構成要素と、外部に設けたオーディオ装置５１が示される。このうち、信号処理部３の低域補正部２１及びこもり音低減部２２と、レシーバ４と、外耳道用マイクロホン５については、上述の補聴器（図２）と同様であるため、説明を省略する。一方、図７の構成のうち図２と異なるのは、外部マイクロホン２及び補聴処理部２０を設けることなく、オーディオ装置５１を低域補正部２１に接続可能に構成した点である。また、一般に、オーディオ用イヤホン５０は音楽を聴くなどに用途に用いられ、例えば、補聴器に比べても周波数帯域が広くなるので、その点を考慮して低域補正部２１、低域反転増幅部４０、信号パイパス部４２の周波数特性を設定することが望ましい。
[Audio earphones]
Hereinafter, embodiments of an audio earphone to which the present invention is applied will be described. Since the audio earphone of the present embodiment is common to the above-described hearing aid in many respects, the following mainly describes differences. FIG. 7 is a block diagram showing a configuration of main parts including the signal processing unit 3 and its peripheral part in the audio earphone 50 of the present embodiment. FIG. 7 shows components incorporated in an audio earphone main body (not shown) and an audio device 51 provided outside. Among these, the low-frequency correction unit 21 and the booming sound reduction unit 22, the receiver 4, and the ear canal microphone 5 of the signal processing unit 3 are the same as the above-described hearing aid (FIG. 2), and thus the description thereof is omitted. On the other hand, the configuration of FIG. 7 differs from that of FIG. 2 in that the audio device 51 can be connected to the low frequency correction unit 21 without providing the external microphone 2 and the hearing aid processing unit 20. In general, the audio earphone 50 is used for listening to music and the like. For example, since the frequency band is wider than that of a hearing aid, the low frequency correction unit 21, the low frequency inversion amplification unit are considered in consideration of this point. 40, it is desirable to set the frequency characteristics of the signal bypass section 42.
図７において、オーディオ装置５１から送出されるオーディオ信号は、低域補正部２１及びこもり音低減部２２を経由してレシーバ４から音として出力される。レシーバ４、外耳道用マイクロホン５及びこもり音低減部２２による負帰還ループと、信号バイパス部４２の役割については、既に説明した通りであり、負帰還ループにおける発振を有効に防止しつつ、こもり音を十分に低減できる。 In FIG. 7, the audio signal transmitted from the audio device 51 is output as a sound from the receiver 4 via the low frequency correction unit 21 and the booming sound reduction unit 22. The roles of the negative feedback loop by the receiver 4, the ear canal microphone 5, and the muffled sound reduction unit 22 and the role of the signal bypass unit 42 are as described above, and while effectively preventing oscillation in the negative feedback loop, It can be reduced sufficiently.
［耳せん］
以下、本発明を適用した耳せんの実施形態を説明する。本実施形態の耳せんは、その主要部が上述の補聴器の部分的な構成と共通であるため、以下では主に異なる点について説明する。図８は、本実施形態の耳せん６０において、信号処理部３であるこもり音低減部２２及びその周辺部を含む主要部の構成を示すブロック図である。図８には、例えば、シリコン系、ウレタン系、ＡＢＳ系などの樹脂材料により形成される耳せん本体（不図示）に内蔵される構成要素が示される。また、図８の耳せん６０は、電気回路に電力を供給する電池等の電源（不図示）を備えている。このうち、こもり音低減部２２（信号処理部３）、レシーバ４と、外耳道用マイクロホン５については、上述の補聴器（図２）と同様であるため、説明を省略する。図８の構成のうち図２と異なるのは、外部マイクロホン２、補聴処理部２０、低域補正部２１を設けない点と、こもり音低減部２２に対して入力信号Ｓｉｎを入力することなく閉じた負帰還ループを構成した点である。
[Earplugs]
Hereinafter, embodiments of the earplug to which the present invention is applied will be described. Since the main part of the earplug of this embodiment is the same as the partial configuration of the above-described hearing aid, the following mainly describes differences. FIG. 8 is a block diagram showing a configuration of main parts including the booming sound reduction unit 22 that is the signal processing unit 3 and its peripheral part in the earplug 60 of the present embodiment. FIG. 8 shows components incorporated in an earplug main body (not shown) formed of, for example, a resin material such as silicon, urethane, or ABS. The earplug 60 of FIG. 8 includes a power source (not shown) such as a battery that supplies electric power to the electric circuit. Among these, the booming sound reduction unit 22 (signal processing unit 3), the receiver 4, and the ear canal microphone 5 are the same as the above-described hearing aid (FIG. 2), and thus description thereof is omitted. 8 differs from FIG. 2 in that the external microphone 2, the hearing aid processing unit 20, and the low frequency correction unit 21 are not provided, and the input signal Sin is not input to the booming sound reduction unit 22. The negative feedback loop is constructed.
一般的な耳せんは、補聴器やオーディオ用イヤホンのように外部からの入力信号は不要であり、通常は電気回路が不要である。しかし、耳せんを使用者が装着している際に外耳道１０を密閉した状態になると、こもり音により不快感は避けられない。よって、本実施形態の耳せん６０は、こもり音低減部２２の電気回路を搭載することにより、こもり感を低減して使用者の不快感の解消を図っている。この場合、こもり音だけではなく、使用者の頭部周囲から外耳道１０に侵入する音についても有効に低減できる。レシーバ４、外耳道用マイクロホン５及びこもり音低減部２２による負帰還ループと、信号バイパス部４２の役割については、既に説明した通りであり、負帰還ループにおける発振を有効に防止しつつ、こもり音を十分に低減できる。 A typical earplug does not require an external input signal like a hearing aid or an audio earphone, and usually does not require an electric circuit. However, if the ear canal 10 is sealed when the user wears the earplug, discomfort is unavoidable due to the muffled sound. Therefore, the earplug 60 of this embodiment is equipped with the electric circuit of the booming sound reduction unit 22 to reduce the feeling of crowding and to eliminate the user's discomfort. In this case, it is possible to effectively reduce not only the humming sound but also the sound that enters the ear canal 10 from around the user's head. The roles of the negative feedback loop by the receiver 4, the ear canal microphone 5, and the muffled sound reduction unit 22 and the role of the signal bypass unit 42 are as described above, and while effectively preventing oscillation in the negative feedback loop, It can be reduced sufficiently.
［こもり音低減装置］
上記各実施形態では、本発明を、補聴器１、オーディオ用イヤホン５０、耳せん６０にそれぞれ適用する場合を説明したが、本発明は、これらに限らず多様な形態のこもり音低減装置に適用することができる。すなわち、図２、図７、図８にそれぞれ示したこもり音低減部２２と、レシーバ４と、外耳道用マイクロホン５とを備えたこもり音低減装置を構成し、単独で、あるいは他の機器に組み込んで本発明を適用することができる。このようなこもり音低減装置は、使用者の外耳道１０に装着可能で、こもり音を低減する機能を有していれば、それ以外の点については多様な機能や構成を持たせることができる。
[Cloud noise reduction device]
In each of the above-described embodiments, the case where the present invention is applied to the hearing aid 1, the audio earphone 50, and the earplug 60 has been described. However, the present invention is not limited to these, and is applied to various types of booming sound reduction devices. be able to. That is, a booming noise reduction device including the booming noise reduction unit 22, the receiver 4, and the ear canal microphone 5 shown in FIG. 2, FIG. 7, and FIG. 8, respectively, is configured alone or incorporated in another device. The present invention can be applied. Such a booming noise reduction device can be mounted on the user's external auditory canal 10 and can have various functions and configurations for other points as long as it has a function of reducing the booming noise.
１…補聴器
２…外部マイクロホン
３…信号処理部
４…レシーバ
５…外耳道用マイクロホン
６…電池ホルダ
７…ボタン電池
１０…外耳道
１１…鼓膜
２０…補聴処理部
２１…低域補正部
２２…こもり音低減部
３０…フィルタ
３１…増幅器
３２…加算部
４０…低域反転増幅部
４１…加算部
４２…信号バイパス部
４３…加算部
５０…オーディオ用イヤホン
５１…オーディオ装置
６０…耳せん
DESCRIPTION OF SYMBOLS 1 ... Hearing aid 2 ... External microphone 3 ... Signal processing part 4 ... Receiver 5 ... Microphone 6 for external ear canal ... Battery holder 7 ... Button battery 10 ... External ear canal 11 ... Tympanic membrane 20 ... Hearing aid processing part 21 ... Low-frequency correction part 22 ... Reduction of booming sound Section 30 ... Filter 31 ... Amplifier 32 ... Addition section 40 ... Low frequency inversion amplification section 41 ... Addition section 42 ... Signal bypass section 43 ... Addition section 50 ... Audio earphone 51 ... Audio device 60 ... Auricle
Claims (7)
前記外耳道内を伝搬する音を電気信号に変換して負帰還経路に出力する外耳道用マイクロホンと、
前記負帰還経路の電気信号のうち所定の低域周波数成分を前記伝送経路に負帰還させる負帰還部と、
前記レシーバの入力側から前記外耳道用マイクロホンの出力側までを電気的に接続する信号バイパス部と、
を備え、
前記信号バイパス部は、前記伝送経路の電気信号のうち、少なくとも所定の周波数成分を所定のゲインで増幅し、前記負帰還経路に伝送することを特徴とするこもり音低減装置。 A receiver that converts an electrical signal input through the transmission path into sound and outputs the sound to a space in the ear canal;
A microphone for an external auditory canal that converts sound propagating in the ear canal into an electrical signal and outputs it to a negative feedback path;
A negative feedback unit that negatively feeds back a predetermined low-frequency component of the electrical signal of the negative feedback path to the transmission path;
A signal bypass unit that electrically connects the input side of the receiver to the output side of the ear canal microphone;
With
The signal bypass unit amplifies at least a predetermined frequency component of the electrical signal of the transmission path with a predetermined gain and transmits the amplified signal to the negative feedback path.
前記第２のバイパス部は、前記伝送経路の電気信号を増幅する第２のアンプと、前記伝送経路の電気信号から所定の高域周波数成分を抽出するハイパスフィルタとにより構成される、
ことを特徴とする請求項３に記載のこもり音低減装置。 The first bypass unit includes a first amplifier that amplifies an electric signal of the transmission path,
The second bypass unit includes a second amplifier that amplifies the electrical signal of the transmission path, and a high-pass filter that extracts a predetermined high-frequency component from the electrical signal of the transmission path.
The booming noise reduction device according to claim 3.
外部音を電気信号に変換する外部マイクロホンと、
前記外部マイクロホンの出力信号に対し補聴処理を施す補聴処理部と、
前記補聴処理部の出力信号に対し、前記負帰還部による前記低域周波数成分の減衰分を予め補正する低域補正部と、
を備えることを特徴とする補聴器。 A booming noise reduction device according to any one of claims 1 to 4,
An external microphone that converts external sound into an electrical signal;
A hearing aid processing unit that performs hearing aid processing on the output signal of the external microphone;
A low-frequency correction unit that corrects in advance the attenuation of the low-frequency component by the negative feedback unit, with respect to the output signal of the hearing aid processing unit;
A hearing aid characterized by comprising:
外部からの入力信号に対し、前記負帰還部による前記低域周波数成分の減衰分を予め補正する低域補正部と、
を備えることを特徴とするオーディオ用イヤホン。 A booming noise reduction device according to any one of claims 1 to 4,
A low-frequency correction unit that corrects in advance the attenuation of the low-frequency component by the negative feedback unit with respect to an external input signal;
An audio earphone characterized by comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013091828A JP6081854B2 (en) | 2013-04-24 | 2013-04-24 | Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013091828A JP6081854B2 (en) | 2013-04-24 | 2013-04-24 | Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014216799A JP2014216799A (en) | 2014-11-17 |
| JP6081854B2 true JP6081854B2 (en) | 2017-02-15 |
Family
ID=51942161
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013091828A Active JP6081854B2 (en) | 2013-04-24 | 2013-04-24 | Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6081854B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000019605A2 (en) * | 1998-09-30 | 2000-04-06 | House Ear Institute | Band-limited adaptive feedback canceller for hearing aids |
| JP4010968B2 (en) * | 2003-03-26 | 2007-11-21 | リオン株式会社 | Hearing aid with howling suppression |
| JP2011188334A (en) * | 2010-03-10 | 2011-09-22 | Panasonic Corp | Hearing aid |
-
2013
- 2013-04-24 JP JP2013091828A patent/JP6081854B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014216799A (en) | 2014-11-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9949048B2 (en) | Controlling own-voice experience of talker with occluded ear | |
| US11297443B2 (en) | Hearing assistance using active noise reduction | |
| CN107787589B (en) | noise canceling system, earphone and electronic device | |
| US9466281B2 (en) | ANC noise active control audio headset with prevention of the effects of a saturation of the feedback microphone signal | |
| US9247337B2 (en) | Headphone and headset | |
| US8948409B2 (en) | Audio headset with active noise control of the non-adaptive type for listening to an audio music source and/or for “hands-free” telephony functions | |
| JP5610945B2 (en) | Noise canceling headphones and noise canceling earmuffs | |
| JP2017163531A (en) | Head-wearable hearing device | |
| CN109565626B (en) | Acoustic open type earphone with active noise reduction function | |
| US11438711B2 (en) | Hearing assist device employing dynamic processing of voice signals | |
| JP6495448B2 (en) | Self-voice blockage reduction in headset | |
| EP2830324B1 (en) | Headphone and headset | |
| US20220014849A1 (en) | Earpiece, hearing device and system for active occlusion cancellation | |
| EP3544313B1 (en) | Sound output device and control method for sound output device | |
| JP6196070B2 (en) | Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug | |
| JP6081854B2 (en) | Muffled sound reduction device, hearing aid equipped with the same, earphone for audio, earplug | |
| WO2023283285A1 (en) | Wearable audio device with enhanced voice pick-up | |
| JP2004048207A (en) | Hearing aid | |
| JP6297950B2 (en) | Boom sound reduction device, hearing aid equipped with the same, audio earphone, earplug, and electroacoustic transducer | |
| JP2017011383A (en) | Muffled sound reduction device, hearing aid having the same, audio earphone, earplug and electric acoustic converter | |
| US20230136161A1 (en) | Apparatus and method for performing active occulsion cancellation with audio hear-through | |
| JP2014165688A (en) | Hearing aid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20160309 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20161219 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20170117 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170119 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6081854 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |