CN105103219B - The method for reducing noise - Google Patents
The method for reducing noise Download PDFInfo
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- CN105103219B CN105103219B CN201380075550.3A CN201380075550A CN105103219B CN 105103219 B CN105103219 B CN 105103219B CN 201380075550 A CN201380075550 A CN 201380075550A CN 105103219 B CN105103219 B CN 105103219B
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1787—General system configurations
- G10K11/17873—General system configurations using a reference signal without an error signal, e.g. pure feedforward
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17857—Geometric disposition, e.g. placement of microphones
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/10—Applications
- G10K2210/111—Directivity control or beam pattern
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/10—Applications
- G10K2210/12—Rooms, e.g. ANC inside a room, office, concert hall or automobile cabin
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/301—Computational
- G10K2210/3055—Transfer function of the acoustic system
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K2210/00—Details of active noise control [ANC] covered by G10K11/178 but not provided for in any of its subgroups
- G10K2210/30—Means
- G10K2210/321—Physical
- G10K2210/3215—Arrays, e.g. for beamforming
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- Acoustics & Sound (AREA)
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- Soundproofing, Sound Blocking, And Sound Damping (AREA)
Abstract
The invention discloses a kind of methods for reducing noise, comprising: analysis noise determines the sound source characteristics of noise；The sound-source signal for acquiring noise, is corrected processing, delay process, reverse process and conversion process to the sound-source signal of acquisition, obtains the first reconstruction sound source；The sound and noise for propagating the first reconstruction sound source are offset in the first compensation point.The present invention passes through acquisition noise sound-source signal and series of processes, manufacture one opposite with noise sound source direction of vibration when reaching at compensation point, and other features then with the identical reconstruction sound source of noise sound source, by artificially creating the path met, make noise and reconstruction sound source in the same time, it meets on same position, it eliminates because of the various errors of bring during manufacture reconstruction sound source, " time difference " for making noise and reproducing between sound source arrival compensation point is intended to zero, realize the counteracting to noise, the noise of instantaneous variation can effectively be offset, in the environment that can be adapted for the large spaces such as industrial production.
Description
Technical field
The present invention relates to a kind of methods for reducing noise.
Background technique
There are mainly two types of the methods of current reduction noise: active noise reduction and passive noise reduction.Active noise reduction is to pass through noise reduction
System generates the reversed sound wave equal with ambient noise, noise vibration is offset, to realize noise reduction.Passive noise reduction mainly passes through
It is absorbed sound using sound-absorbing material, or stop outside noise by forming enclosure space and acoustic material, to realize noise reduction.
Existing noise cancelling headphone is just combined with active noise reduction and the mode of passive noise reduction carries out noise reduction.On the one hand, it drops
Earphone of making an uproar forms enclosure space by surrounding ear, and stops outside noise using acoustic materials such as silica gel earplugs；Another party
Face is mounted with signal microphone in noise cancelling headphone, can be used for detecting low frequency noise in the environment that ear can be heard (100~
1000Hz).Noise signal is reached control circuit by signal microphone, and control circuit carries out real-time operation, sent out by Hi-Fi loudspeaker
It penetrates and carrys out offset noise with noise opposite in phase (differing 180 °), the identical sound wave of amplitude.
But it if the noise-reduction method of above-mentioned noise cancelling headphone is applied to the biggish place in the spaces such as workshop, remains
In following defect:
1, noisy environment biggish for spaces such as workshops, noise are often formed by large-scale production machine, and
People needs to work in these production machines, except ear is non-fully encased, to form an enclosure space otherwise to separate
The sound source of noise almost cannot achieve.
2, noise cancelling headphone is the masking effect using human ear mostly, and is made an uproar by double MIC identifications, filtering voice, separation
Sound and amplification voice technology, to reach noise reduction effect.Noise mainly is covered by amplifying this sound source, is not true
The mode of sound wave counteracting is passed through to realize noise reduction, and covers making an uproar for large-scale production machine generation by generating a sound
Sound only can bring serious harm to the ear of people.
3, the collection signal microphone in noise cancelling headphone is not fixed at a distance from noise, is not supported as sound phase
The datum mark to disappear, meanwhile, Hi-Fi sound horn direction and original signal are in the same direction, and counteracting cannot be constituted under conditions of the velocity of sound is equal
Condition.
4, since the speed of sound is that each frequency is consistent, must for use as the sound source of counteracting and the communication process of noise
It is poor that so there are certain times, since the space in earphone is small, just offsets it is also possible to realizing.But in the biggish environment in space
In, this time difference is amplified.In this way, the sound wave and noise that pass through Hi-Fi horn launch are all on amplitude, time, space
It is difficult to matched, same position cannot be reached simultaneously, cannot not only be cancelled out each other with the sound wave of noise, it is also possible to so that noise quilt
Reinforce.
Summary of the invention
At least one of the object of the present invention is to provide a kind of methods for reducing noise, to solve the above technical problems.
According to an aspect of the invention, there is provided a kind of method for reducing noise, comprising the following steps:
(1) analyze noise, determine the sound source characteristics of noise, sound source characteristics refer to the direction of propagation of sound, frequency, wavelength,
The transient state characteristic of the direction of propagation, frequency, wavelength, the amplitude of the moment of the inherent features such as amplitude and sound etc.；
(2) noise sound-source signal is acquired (generally to carry out close to noise sounding point and in the side of the direction of propagation of noise
Acquisition), according to the sound source characteristics of noise being handled as follows to the sound-source signal of acquisition: correction process, delay process and anti-
To processing and conversion process, the first reconstruction sound source is obtained；
(3) sound and noise for propagating the first reconstruction sound source are offset in the first compensation point, obtain level-one noise-reducing.
The present invention manufactures a reconstruction sound source, the reconstruction sound source by acquisition noise sound-source signal and a series of processing
It is opposite with noise sound source direction of vibration and in addition to direction of vibration with noise sound source other sound source characteristics having the same.Pass through people
For one noise of setting and the path met of reconstruction sound source, so that two sound waves is met on the same time, same position, eliminate
Noise and reconstruction sound source reach " time difference " (" time difference " is allowed to tend to zero) between compensation point, realize supporting for noise
Disappear.Correction process of the invention can effectively offset the noise of instantaneous variation, and noise-reduction method of the invention is applicable in
In the environment of the large spaces such as industrial production, the harm of noise bring is reduced.
In some embodiments, noise sound-source signal can be acquired by heart-shaped directional microphone, pass through sound transducing
Device (such as: loudspeaker, speaker, plate acoustical generator, Haier's acoustical generator, piezo-electric acoustic generator) propagates the first reconstruction sound source.
High performance heart directional microphone and sonic transducer can be more effectively completed the reduction work of sound, it is possible to reduce the howl of loop
It cries, prevents audio distortions.
In some embodiments, the first compensation point can be close to the sounding point of the first reconstruction sound source, it is, first supports
Disappear and is a little less than the first compensation point at a distance from the sounding point of noise at a distance from the sounding point of the first reconstruction sound source.Wherein,
1/2 effect of the high-frequency wavelength (λ) that one compensation point is less than noise at a distance from the sounding point of the first reconstruction sound source is preferable, and first
1/4 effect of the high-frequency wavelength that compensation point is less than noise at a distance from the sounding point of the first reconstruction sound source is best.Acquire noise sound
Source signal is carried out in close noise sounding point and on the direction of propagation of noise, and the sounding point of the close reconstruction sound source of compensation point,
So that thering is time enough to carry out relevant correction and processing to the sound source of acquisition, so that noise and reconstruction sound source can be realized
Compensation point is reached simultaneously, is reduced " time difference ", realization is completely counterbalanced by.
In some embodiments, above-mentioned steps (2) may include:
A/D conversion is carried out to the sound-source signal of acquisition；
Sound-source signal bring error is given in correction in collection process；
Delay process is carried out to the sound-source signal of acquisition, by load time delayed signal enable sound-source signal be converted into sound into
Row propagates Shi Nengyu noise and reaches the first compensation point simultaneously；
Conversion process is to carry out that (the distance between heart-shaped directional microphone and sonic transducer are fixed using sonic transducer
), before conversion process, processing is corrected to sonic transducer；
Reverse process is carried out to sound-source signal, so that the direction of vibration of sound-source signal is opposite with the direction of vibration of noise；
It corrects in delay process, reverse process and conversion process to sound-source signal bring error；
D/A conversion is carried out to sound-source signal, sound energy is converted into, to can be carried out propagation.
Due to used in the process of acquisition, broadcasting, transmission etc. hardware device (such as: heart-shaped directional microphone, sonic transducer,
ADC, DAC, DSP handle chip, register, memory, power amplifier, connector, transmission link etc.) it all can be more or less
Make the sound-source signal of acquisition generate variation (namely " be distorted ", be primarily referred to as causing due to equipment defect itself or equipment between
Convert that the factors such as inertial characteristics, various reflections, diffraction, hardware and software of transmittance process and sound movement generate add or
Lack sound wave), meanwhile, system after working after a period of time, in fact it could happen that the minor change of the electric property of element.For sound
For wave is offset, these subtle differences not only will be prevent two sound sources from offsetting, or even be also possible to lead to two sound source phases
Mutually superposition, causes undesirable consequence.Therefore, only just sound-source signal can be made tight by a series of this accurately correction and adjustment
Lattice meet the transient state feature of noise vibration, also just can ensure that reconstruction sound source and noise while reaching compensation point and supporting in compensation point
Disappear.
In some embodiments, in the method for above-mentioned reduction noise, level-one noise-reducing can also be carried out following
Processing:
Level-one noise-reducing sound-source signal is acquired, to measure the neutralization effect of the first reconstruction sound source and noise, and according to this survey
Amount result is corrected the length or tune of processing, adjustment time delayed signal load delay to the sound-source signal processing in step (2)
The position of whole first compensation point.Whether the noise signal of acquisition and treated sound-source signal are distorted, and can pass through this
Step obtains.Meanwhile by this step, the matching degree learnt compensation point position noise and reproduce sound source can also be tested.
By above-mentioned measurement, offset result can be not only monitored, the feature of reconstruction sound source can also be adjusted in time, offset
The elements such as the position of point, it is ensured that noise and reconstruction sound source can reach compensation point simultaneously and realize and be completely counterbalanced by.
In some embodiments, level-one noise-reducing can also be carried out the following processing:
Level-one noise-reducing is analyzed, determines the sound source characteristics of level-one noise-reducing；
The sound-source signal for acquiring level-one noise-reducing, according to the sound source characteristics of level-one noise-reducing to the level-one noise-reducing of acquisition
Sound-source signal is handled as follows: correction process, delay process, reverse process and conversion process, obtains the second reconstruction sound source；
The sound for propagating the second reconstruction sound source is offset with level-one noise-reducing in the second compensation point, and second level noise reduction is obtained
Sound.
Above-mentioned treatment process can further circulate operation, for example, it is also possible to be located as follows again to second level noise-reducing again
Reason:
Second level noise-reducing is analyzed, determines the sound source characteristics of second level noise-reducing；
The sound-source signal for acquiring second level noise-reducing, according to the sound source characteristics of second level noise-reducing to the second level noise-reducing of acquisition
Sound-source signal is handled as follows: correction process, delay process, reverse process and conversion process, obtains third reconstruction sound source；
The sound for propagating third reconstruction sound source is offset with second level noise-reducing in third compensation point.
It is more difficult to pass through noise reduction requirement required for a noise reduction process just reaches for the noise of some complexity, therefore,
The fractionation that frequency range and covering can be carried out to noise carries out gradually noise reduction to the noise of fractionation, realizes noise reduction by multistep treatment
Purpose.
Detailed description of the invention
Fig. 1 is the schematic illustration for the method that one embodiment of the present invention reduces noise.
Fig. 2 is to obtain the process flow diagram of level-one noise-reducing in Fig. 1.
Fig. 3 is the response diagram of amplitude size on each Frequency point of sonic transducer before correcting.
Fig. 4 is the response diagram of amplitude size on each Frequency point of sonic transducer after correcting.
Fig. 5 is the impulse response figure of sonic transducer before correcting.
Fig. 6 is the impulse response figure of sonic transducer after correction.
Fig. 7 is the variation diagram by noise before and after the flow processing in Fig. 2.
Specific embodiment
Present invention will be explained in further detail with reference to the accompanying drawing.
Fig. 1 schematically shows the schematic illustration of the method for the reduction noise of one embodiment of the present invention.
As shown in Figure 1, a kind of method for reducing noise, comprising the following steps:
Noise 101 is analyzed, determines the sound source characteristics of noise 101.
It is made an uproar at 101 sounding point of noise and in the side of the direction of propagation of noise by heart-shaped directional microphone acquisition
The sound-source signal of sound 101.
The sound-source signal of acquisition is corrected according to the sound source characteristics of noise 101 selection suitable hardware and software,
A series of processing such as delay, reversed.
Sound energy will be converted by treated signal by sonic transducer, obtain the first reconstruction sound source 103, first
Reconstruction sound source 103 is propagated, and is carried out in the first compensation point 102 (close to the sounding point of the first reconstruction sound source 103) with noise 101
It offsets, obtains level-one noise-reducing 104.
The sound-source signal of level-one noise-reducing 104 is acquired, to measure the neutralization effect of the first reconstruction sound source 103 and noise 101,
And software and hardware (the even replacement software of the sound-source signal of the noise of suitable processing acquisition is selected according to this measurement result
And hardware), to sound-source signal processing be corrected processing, adjustment time delayed signal load delay length or adjustment first offset
The position of point.
Level-one noise-reducing 104 is analyzed, determines the sound source characteristics of level-one noise-reducing 104.
Passing through heart at 104 sounding point of level-one noise-reducing and in the side of the direction of propagation of level-one noise-reducing 104
Directional microphone is acquired the sound-source signal of level-one noise-reducing 104.
According to the suitable hardware and software of the sound source characteristics of level-one noise-reducing 104 selection come the level-one noise-reducing to acquisition
104 sound-source signal is corrected, is delayed, a series of processing such as reversed.
Sound energy will be converted by treated signal by sonic transducer, obtain the second reconstruction sound source 106, second
Reconstruction sound source 106 is propagated, in the second compensation point 105 (close to the sounding point of the second reconstruction sound source 106) and level-one noise-reducing
104 are offset, and second level noise-reducing 107 is obtained.
The sound-source signal of second level noise-reducing 107 is acquired, to measure supporting for the second reconstruction sound source 106 and level-one noise-reducing 104
Disappear effect, and according to the software of the sound-source signal of the level-one noise-reducing 104 of the suitable processing acquisition of this measurement result selection and firmly
Part (even replacement software and hardware), and the various parameters in adjustment treatment process.
Second level noise-reducing 107 is analyzed, determines the sound source characteristics of second level noise-reducing 107.
Passing through heart at 107 sounding point of second level noise-reducing and in the side of the direction of propagation of second level noise-reducing 107
Directional microphone is acquired the sound-source signal of second level noise-reducing 107.
According to the suitable hardware and software of the sound source characteristics of second level noise-reducing 107 selection come the second level noise-reducing to acquisition
107 sound-source signal carries out a series of processing,.
It will be converted into sound energy by treated signal by sonic transducer, and obtain third reconstruction sound source 109, third
Reconstruction sound source 109 is propagated, in third compensation point 108 (close to the sounding point of third reconstruction sound source 109) and second level noise-reducing
10 are offset, and a squelch up to standard, i.e. noise elimination sound field 110 are obtained.
The sound-source signal of noise elimination sound field 110 is acquired, is imitated with measuring the counteracting of third reconstruction sound source 109 and second level noise-reducing 10
Fruit, and the software and hardware of the sound-source signal of the suitable second level noise-reducing 10 for handling acquisition is selected (very according to this measurement result
To be replacement software and hardware), and adjustment treatment process in various parameters.
In the present embodiment, the noise reduction process of three-level is carried out to noise 101.It but in other embodiments, can be according to need
It wants, the noise reduction process of multistage (such as: second level, level Four, Pyatyi) is carried out to noise 101, until noise reduction requirement required for reaching.
Fig. 2 shows to obtain the process flow diagram of level-one noise-reducing 104.
As shown in Fig. 2, in the position close to 101 sounding point of noise and the side in the direction of propagation of noise 101, with heart
The sound-source signal (step S201) of the acquisition noise 101 of directional microphone 201.
The sound-source signal of acquisition is converted by A/D, is converted into digital signal (step S202).It makes an uproar at this point, can read
The some inherent features and transient state characteristic of sound 101, such as: frequency, amplitude, phase.According to these features, can choose suitable
Voice processing software and hardware, such as: the sound source of a bass cannot respond to, sometimes very certainly with the sonic transducer of high pitch
It is handled to the sound-source signal for needing multi-transducer to combine.
Due to using heart-shaped directional microphone to be acquired sound-source signal, obtained signal all can more or less have one
A little errors.Generally before using heart-shaped directional microphone, it will be measured by audio analysis system, obtain the heart
The offset and corrected value that the inherent characteristic of shape directional microphone carries out.It is handled using this offset and corrected value by DSP
The sound-source signal of acquisition is corrected, to correct heart-shaped directional microphone 201 to sound-source signal bring error (step
S203).The information of correction includes: the number of phases between the sound pressure correction data of each Frequency point of band internal, each Frequency point
According to consistent with former noise signal by correcting the signal that heart-shaped directional microphone can be made to capture.
Since sonic transducer (sonic transducer used in the present embodiment is dynamic speaker) is mainly accomplished that telecommunications
The function of number being converted to acoustical signal, needs to complete the frequency conversion of a frequency range.And each Frequency point is in the sounding of sonic transducer
Position and starting time is not identical, thus causes the amplitude of each frequency, the difference of frequency relative phase.Therefore, it removes
Heart-shaped directional microphone 201 is corrected to outside sound-source signal bring error, it is also desirable to correct sonic transducer and give sound-source signal band
The error (step S204) come, to realize that the loyalty for original signal restores.
Other than heart-shaped directional microphone and sonic transducer, processor, ADC, DAC in entire processing system, storage
Device, register, power amplifier, transmission link etc. are likely to cause declining for the delay of signal, the variation of frequency or amplitude
Subtract, requires to be corrected (step S205).
The processing for correcting heart-shaped directional microphone, sonic transducer, the various hardware of system and transmission link can pass through number
The hardware and software of word processing is realized, the hardware cooperation such as processor or the dsp chip of profession software algorithm can be selected to unite
One processing.
The present embodiment carries out test and the school of energy converter and system by way of audio analysis system and audio DSP processing
Just.Audio-frequency test is divided into steady state test and transient test, and the present embodiment selects SMAARTLIVE7 software to be tested.Stable state
Test method are as follows: system itself issues continuous test signal, this test signal is the noise signal of a broadband, with this
As the benchmark of test, this benchmark is indicated with a channel data.This benchmark is into a loop, on a tester
It reflects, is loop due to outputting and inputting, display is become straight line by system.Same reference signal, which is emitted to, to be needed to measure
System, measuring system response after, pass through the acquisition devices such as heart-shaped directional microphone (can be electric signal and acoustical signal) FFT
(fast Fourier) is converted, and is shown in other channel, and obtained result is compared i.e. two or more with original signal
A channel is compared, and can intuitively see the problem of comparing place.Steady state test is measured with continuous signal, wink
State test is tested with pulse signal.Carrying out relative phase test is also same principle, using fixed frequency as phase initial point,
Other frequencies as a comparison, available different phase response i.e. time response difference.
And the process of signal processing is that general processor or professional DSP processing chip are carried out in conjunction with corresponding software.
This example uses the hardware system of the SHARC ADSP-21448 processing chip composition of ADI company and corresponding software is combined to carry out
Signal processing.Signal processing are as follows: (1) according to the heart-shaped directional microphone calibration data tested in advance, converted to by A/D
Sound-source signal carry out input offset processing (including its amplitude-frequency response and phase response feature), with amendment because measurement Mike with
The error (step S203) entered；(2) according to above-mentioned audio-frequency test to correct the error that sonic transducer is brought into, including amplitude-frequency is rung
It answers, the compensation of phase response, transient response and amendment (step S204)；(3) according to above-mentioned audio-frequency test in whole system
The error brought into, including amplitude-frequency response, phase response, the compensation of transient response and amendment (step S205).
In addition to this, the present embodiment additionally use the integration algorithms such as FIR filter and ALLPASS filter carry out amplitude-frequency and
The correction of phase, and carry out by the way of applying reverse signal the correction of the response to transient state.
Fig. 3 is the response diagram of amplitude size on each Frequency point of sonic transducer before correcting, and Fig. 4 is that sonic transducer is each after correcting
The response diagram of amplitude size on a Frequency point.By Fig. 3 and Fig. 4 as it can be seen that after corrected, each frequency of original transducer is had modified
The response of amplitude size on point, phase response is also very straight, is consistent the signal output and input.
Fig. 5 is the impulse response figure of sonic transducer before correcting, and Fig. 6 is the impulse response figure of sonic transducer after correction.By Fig. 5
With Fig. 6 as it can be seen that not optimizing before, attached the very big extra-pulse of several amplitudes below main pulse and on the subsequent time
Big remained shock pulse；Main clutter is modified by the mode of inverse direction filter, main clutter becomes smaller, and adds clutter and becomes
It is few, original waveform is closer in terms of transient state angle.
The revised correction result of above step S203~S205 is all superimposed upon the letter of former heart-shaped directional microphone input
In number, material is thus formed the signals of a comprehensive modification.
Using above-mentioned hardware and software, to one time delayed signal (step S206) of modified signal loading, then carry out anti-
To processing (step S207).Then, D/A processing is carried out to signal, be converted into analog signal (step S208), analog signal is defeated
Power amplifier (step S209) is arrived out, finally, propagating by loudspeaker 206 it, obtains the first reconstruction sound source in this way
103 (step S210).
It is propagated in the path that first reconstruction sound source 103 is set in air, the first compensation point 102 is close to loudspeaker
206, the first reconstruction sound source 103 is offset with noise 101 in the first compensation point 102, obtains level-one noise-reducing 104.This implementation
In example, the first compensation point 102 is less than the 1/2 of noise wavelength at a distance from the sounding point of the first reconstruction sound source 103, in other implementations
In example, the first compensation point 102 is less than the 1/4 of noise wavelength at a distance from the sounding point of the first reconstruction sound source 103.
First measurement microphone 301 can be set in the first compensation point 102, and in (the noise elimination sound of level-one noise-reducing 104
) at setting second measurement microphone 303, by test macro 302 to first measurement microphone 301 acquire sound-source signal with
Noise signal is compared, is compared to the sound-source signal and noise signal of the second measurement acquisition of microphone 303, to judge to drop
The effect made an uproar.At the same time, according to this effect, processing system can further be corrected.
In conclusion the present invention is to carry out system call interception and matched by three circuits and step.
First adjustment circuit are as follows: first pass around audio analysis system for by heart-shaped directional microphone 201, signal processing
The reconstruction sound system of the compositions such as hardware, power amplifier, sonic transducer, link and plug-in unit carries out integration test.Issue one
A signal gives heart-shaped directional microphone 201, and reconstruction sound system available in this way is measured by the first measurement microphone 301
As a result, this result is determined into the consistent degree of two signals compared with original test signal, it is adjustable to entire with this
The correction parameter of system.
To the debugging process of the parameter of whole system are as follows:
1, heart-shaped directional microphone 201 is individually adjusted, mainly by being corrected with same standard source method.I.e. with one
The sound source (responding good loudspeaker) of standard is made as measurement sound source with the measurement microphone for having obtained and having had corrected that
For standard of comparison, by audio analysis system it can be concluded that difference between two microphones, this difference have generally comprised frequency
Rate response and two item data of phase response, this data obtain after be exactly heart directional microphone 201 correction parameter.This ginseng
Number is directly inputted in the offset data of dsp software program, completes the adjustment to heart-shaped 201 parameter of directional microphone.
2, sonic transducer is individually adjusted, the measurement of sonic transducer, including stable state and wink are mainly carried out with audio analysis system
The two major classes of state.Carry out the correction of amplitude-frequency, phase, transient state by DSP and its software, the software of the data storage of correction in DSP
In program.
3, the matching degree of reconstruction sound source is adjusted with isolation method.It (can be sent out by loudspeaker with the sound source of a determining frequency range
Out), the position that this sound source is isolated to one is first separated, this position is isolated with sonic transducer.This letter is captured with measurement microphone
Number benchmark is formed, while in the identical position of measurement microphone while capturing acoustical signal with heart-shaped directional microphone, this is believed
It number send to reconstruction sound system, capture with another microphone the acoustic signals of reconstruction sound source, this measurement result and base
Standard is compared, and is formed the difference in the reconstruction entire circuit of sound source, correction data is written again the program of DSP.
Second debugging circuit are as follows: the delay of reconstruction sound source and original noise fits through the first measurement microphone 301 warp
Test macro 302 is crossed to obtain.With this, the time delayed signal of load can be corrected.Mainly use short-time pulse as debugging sound source, adjustment
Delay.It uses other loudspeaker to issue short-time pulse as debugging sound source, measures its time for arriving compensation point.Debug sound source position
Fixation is set, measures the time that this sound source reaches compensation point after reproducing sound source sounding again.Compensation point is apart from loudspeaker
Position as close as possible.The position of compensation point is also the position for measuring microphone.Two above data are surveyed by measurement microphone
?.Adjust position of the heart-shaped directional microphone apart from compensation point, make this distance generate reconstruction sound source reach compensation point when
Between be slightly less than debugging sound source reach compensation point time.It can make the two by the way that accurate delay time is added to reconstruction sound source
The time that sound wave reaches compensation point is equal.
Third debug circuit are as follows: can by test macro 302 second measurement microphone 303 obtain reconstruction sound source and
The difference of former noise, at this point it is possible to pass through the comparison consistency of the two sound sources and reversed neutralization effect of reconstruction sound source is repeatedly right
The parameter of whole system is corrected adjustment, can also carry out the optimization of multiple counteracting and scheme.
Because the time that noise 101 reaches the first compensation point 102 is fixed, and can pass through the first measurement Mike
Wind 301 measures.Therefore it may only be necessary to which adjusting distance of the heart-shaped directional microphone 201 apart from compensation point can realize and reconstruction sound
The matching of source system delay, the i.e. delay of reconstruction sound system are big, and distance of the heart-shaped directional microphone 201 apart from compensation point is remote, mesh
Mark is to guarantee that former noise and reconstruction sound source are respectively in compensation point two sides, and propagate in air contrary.At this moment reconstruction sound
The time that source reaches compensation point should be slightly shorter than former noise.Pass through the delay of adjustment reconstruction sound source after measurement, so that it may realize first
The time that reconstruction sound source 103 reaches the first compensation point 102 reaches simultaneously with noise 101.
If noise 101, for quantifiable datum mark, reaches the first compensation point 102 with heart-shaped directional microphone 201
Time be T1, energy converter spatial sound wave reach the first compensation point 102 time T2, entirely from heart-shaped directional microphone
201 capture that the propagation of 101 signal of noise and digital process and correction course delay and all simulations, digital device fixes
It is T3 that delay, which is collectively referred to as the comprehensive delay time of whole system,.It, can be with since sound propagation velocity is slow compared with the spread speed of electric signal
It is adjusted by the distance of heart-shaped directional microphone 201 to compensation point, guarantees T1 > T2+T3, by the sound for giving acquisition in step 204
Source loads a delay T4 and is finely adjusted, so that T1=T2+T3+T4, to make the first reconstruction sound source 103 and noise 101 simultaneously
Reach the first compensation point 102.
Fig. 7 is the variation diagram by noise before and after the flow processing in Fig. 2.As shown in fig. 7, line A is environmental noise curve,
Line B is continuously to obtain one by the processing of step S202~S210 in Fig. 2 from the noise sound source of 30Hz~2KHz frequency range
A reconstruction sound source carries out noise reduction process in Fig. 2, completes to obtain line C after offsetting.As seen from Figure 7, by noise reduction of the invention
After method processing, noise has been substantially reduced.
Above-described is only one embodiment of the present invention.For those of ordinary skill in the art, not
Under the premise of being detached from the invention design, various modifications and improvements can be made, these belong to protection model of the invention
It encloses.
Claims (7)
1. the method for reducing noise, comprising the following steps:
(1) noise is analyzed, determines the sound source characteristics of noise；First compensation point is set；
(2) noise sound-source signal is acquired by cardioid, according to the sound source characteristics of noise and the first compensation point
Position the sound-source signal of acquisition is handled as follows: correction process, delay process, reverse process and conversion process obtain
First reconstruction sound source；Specifically includes the following steps:
A/D conversion is carried out to the sound-source signal of acquisition；
Sound-source signal bring error is given in correction in collection process；The information of correction includes: each Frequency point of band internal
Phase data between sound pressure correction data and each Frequency point；
By the hardware and software of digital processing to the place of heart-shaped directional microphone, sonic transducer, system hardware and transmission link
Reason is corrected；
The test and correction of sonic transducer are carried out by way of audio analysis system and audio DSP processing；Audio testing method
Are as follows: test macro itself issues continuous test signal, and test signal is the noise signal of a broadband, in this, as test
Benchmark, after test macro response, fast Fourier transform, obtained result and original signal are carried out by heart-shaped directional microphone
It is compared, to correct the error that sonic transducer is brought into, compensation including amplitude-frequency response, phase response and transient response and repairs
Just；
Delay process is carried out to the sound-source signal of acquisition, so that sound-source signal is can be carried out biography being converted into sound by loading time delayed signal
Sowing time can reach simultaneously the first compensation point with noise；The method of delay process are as follows: obtain noise using heart-shaped directional microphone as base
On schedule, the time T1 of the first compensation point is reached, and obtains sound wave and reaches the time T2 of the first compensation point from sonic transducer, and obtain
The comprehensive delay time T3 of the system of obtaining is finely adjusted to the sound-source signal load time delayed signal T4 of acquisition, makes T1=T2+T3+T4, with
So that the first reconstruction sound source and noise reach the first compensation point simultaneously；
The delay of first reconstruction sound source and noise fits through the first measurement microphone and obtains by test macro, to correct load
Time delayed signal；Method particularly includes: it uses other loudspeaker to issue short-time pulse as debugging sound source, measures it and offset to first
The time of point；Debugging sound source position is fixed, and measurement debugging sound source reaches first after the first reconstruction sound source sounding and offsets again
The time of point；The position of heart-shaped directional microphone is adjusted to adjust it at a distance from the first compensation point, so that the first reconstruction sound source
The time for reaching the first compensation point is less than the time that debugging sound source reaches the first compensation point, by prolonging to the first reconstruction sound source addition
When the time make the first reconstruction sound source with debugging sound source reach the time of the first compensation point it is equal；
The conversion process is carried out using sonic transducer, before conversion process, is corrected processing to sonic transducer, packet
Include the compensation and amendment of amplitude-frequency response, phase response and transient response；
Reverse process is carried out to sound-source signal, so that the direction of vibration of sound-source signal is opposite with the direction of vibration of noise；
It corrects in the delay process, reverse process and conversion process to sound-source signal bring error, including amplitude-frequency response, phase
Position response and the compensation and amendment of transient response；
D/A conversion is carried out to sound-source signal, sound energy is converted into, to can be carried out propagation；
(3) the first reconstruction sound source is propagated by sonic transducer, the sound and the noise for propagating the first reconstruction sound source
It is offset in the first compensation point, obtains level-one noise-reducing.
2. the method according to claim 1 for reducing noise, which is characterized in that the acquisition noise sound-source signal is leaning on
The sounding point of nearly noise simultaneously carries out on the direction of propagation of noise, sounding of first compensation point close to the first reconstruction sound source
Point.
3. the method according to claim 1 for reducing noise, which is characterized in that first compensation point and the first reconstruction
The distance of the sounding point of sound source is less than the 1/2 of noise high-frequency wavelength.
4. the method according to claim 1 for reducing noise, which is characterized in that first compensation point and the first reconstruction
The distance of the sounding point of sound source is less than the 1/4 of noise high-frequency wavelength.
5. the method according to claim 1 for reducing noise, which is characterized in that further include below being carried out to level-one noise-reducing
Processing:
Level-one noise-reducing sound-source signal is acquired, the neutralization effect of sound source and noise is reproduced in measurement first, and according to this measurement result
Processing, the length of adjustment time delayed signal load delay or adjustment first is corrected to the sound-source signal in step (2) to offset
The position of point.
6. the method according to claim 5 for reducing noise, which is characterized in that further include below being carried out to level-one noise-reducing
Processing:
Level-one noise-reducing is analyzed, determines the sound source characteristics of level-one noise-reducing；
The sound-source signal for acquiring level-one noise-reducing, according to the sound source characteristics of level-one noise-reducing to the sound source of the level-one noise-reducing of acquisition
Signal is handled as follows: correction process, delay process, reverse process and conversion process, obtains the second reconstruction sound source；
The sound for propagating the second reconstruction sound source is offset with the level-one noise-reducing in the second compensation point, and second level noise reduction is obtained
Sound.
7. the method according to claim 6 for reducing noise, which is characterized in that further include below being carried out to second level noise-reducing
Processing:
Second level noise-reducing is analyzed, determines the sound source characteristics of second level noise-reducing；
The sound-source signal for acquiring second level noise-reducing, according to the sound source characteristics of second level noise-reducing to the sound source of the second level noise-reducing of acquisition
Signal is handled as follows: correction process, delay process, reverse process and conversion process, obtains third reconstruction sound source；
The sound for propagating third reconstruction sound source is offset with the second level noise-reducing in third compensation point.
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| CN105679300A (en) * | 2015-12-29 | 2016-06-15 | 努比亚技术有限公司 | Mobile terminal and noise reduction method |
| CN106161780A (en) * | 2016-06-22 | 2016-11-23 | 深圳市金悦通机器人技术有限公司 | There is communicator and the noise-reduction method thereof of speaker decrease of noise functions |
| CN107230481A (en) * | 2017-05-31 | 2017-10-03 | 宇龙计算机通信科技(深圳)有限公司 | Noise processing method and terminal |
| US10096313B1 (en) * | 2017-09-20 | 2018-10-09 | Bose Corporation | Parallel active noise reduction (ANR) and hear-through signal flow paths in acoustic devices |
| CN107749295A (en) * | 2017-10-17 | 2018-03-02 | 张博强 | Wind power generating set Noise Active noise control method and active noise control system |
| CN109545217B (en) * | 2018-12-29 | 2022-01-04 | 深圳Tcl新技术有限公司 | Voice signal receiving method and device, intelligent terminal and readable storage medium |
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| JPH07168582A (en) * | 1993-12-15 | 1995-07-04 | Fuji Heavy Ind Ltd | Noise reduction device in vehicle |
| US6208739B1 (en) * | 1998-05-20 | 2001-03-27 | The Regents Of The University Of Michigan | Noise and vibration suppression method and system |
| KR100423399B1 (en) * | 2001-11-05 | 2004-03-18 | 삼성전기주식회사 | Array type noise reduction filter |
| JP4114583B2 (en) * | 2003-09-25 | 2008-07-09 | ヤマハ株式会社 | Characteristic correction system |
| CN100535992C (en) * | 2005-11-14 | 2009-09-02 | 北京大学科技开发部 | Small scale microphone array speech enhancement system and method |
| CN100524465C (en) * | 2006-11-24 | 2009-08-05 | 北京中星微电子有限公司 | A method and device for noise elimination |
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| US20110091047A1 (en) * | 2009-10-20 | 2011-04-21 | Alon Konchitsky | Active Noise Control in Mobile Devices |
| CN101930731B (en) * | 2010-07-01 | 2011-12-21 | 中国矿业大学(北京) | Mining multi-wave self-adaptive active noise control system |
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