[summary of the invention]
It is good and can reduce the circumscribed de-noising assembly in position of de-noising effect that the technical problem that the present invention need solve provides a kind of de-noising performance.
According to above-mentioned technical problem, designed a kind of de-noising assembly, its objective is such realization: a kind of de-noising assembly, it comprise the band noise voice signal that receives microphone, loud speaker, described reception microphone is received carry out denoising Processing and export de-noising after voice signal signal processing unit and voice signal after the described de-noising is amplified and export the signal amplification unit of amplification voice signal, it is characterized in that: described de-noising assembly also is provided with:
Preceding microphone is used to receive detectable signal and feedback signal is surveyed in output;
Development board comprises the processing unit able to programme and the signal generating unit that sends detectable signal that the detection feedback signal of microphone output before described are carried out analyzing and processing and output dc voltage;
Adder unit is used for described amplification voice signal and detectable signal are carried out the signal stack, and the back voice signal that will superpose is input to described loud speaker.
The present invention also provides a kind of noise-eliminating method of de-noising assembly as claimed in claim 1, and this method comprises the steps:
Step 001, establish some test points, utilize described reception microphone to receive extraneous Noisy Speech Signal at test point place arbitrarily, described Noisy Speech Signal obtains voice signal after the de-noising through the processing of described signal processing unit; Voice signal obtains amplifying voice signal through behind the described signal amplification unit after the de-noising, the multiplication factor that direct voltage by the described processing unit able to programme output of manual adjustments changes described signal amplification unit makes described amplification voice signal reach perfect condition, obtains the dc voltage value of the multiplication factor correspondence of described signal amplification unit this moment;
Signal generating unit by described development board sends the detectable signal of fixed frequency and exports to described loud speaker, and described loud speaker sends sync response after receiving described detectable signal; Utilize described preceding microphone to receive described sync response and export corresponding the detection and feed back signal to described processing unit able to programme; Utilize described processing unit able to programme that described detection feedback signal is done the fft analysis processing and obtain the FFT value;
Step 002, at different test point repeating steps 001, obtain some groups of FFT values and dc voltage value;
Step 003, be abscissa with the FFT value, dc voltage value is that ordinate is set up coordinate system, and some groups of FFT values are drawn in coordinate system with corresponding dc voltage value, draws the modulation relational expression of FFT value and direct voltage by described coordinate system;
Step 004, provide a program read write line, utilize described program read write line described modulation relational expression to be write the processing unit able to programme of described development board;
Step 005, the signal generating unit by described development board send the detectable signal of fixed frequency and export to described loud speaker, and described loud speaker sends sync response after receiving described detectable signal;
Step 006, utilize described before microphone receive described sync response and corresponding detection of output that described loud speaker sends and feed back signal to described processing unit able to programme;
Step 007, utilize described processing unit able to programme that described detection feedback signal is made the direct voltage that fft analysis is handled and output is corresponding;
Step 008, utilize described reception microphone to receive extraneous Noisy Speech Signal and be input to described signal processing unit, voice signal after the output de-noising after described signal processing unit is handled Noisy Speech Signal, by signal amplification unit to described de-noising after voice signal amplify and export and amplify voice signal, input to described loud speaker after utilizing described adder unit with described amplification language signal and detectable signal stack.
Preferably, described detectable signal is a 250Hz pure-tone pulse signal.
Preferably, the time interval that described preceding microphone receives described detectable signal equated with the time interval that described signal generating unit sends described detectable signal, and the duration that described preceding microphone receives described detectable signal is the twice that described signal generating unit sends the duration of described detectable signal.
Preferably, the time interval that described signal generating unit sends described detectable signal is 1s, and the duration of at every turn sending described detectable signal is 10ms; The time interval that described preceding microphone receives described detectable signal is 1s, and the duration that at every turn receives described detectable signal is 20ms.
Preferably, described test point is provided with 7, each described test point test 7 times.
Compare with correlation technique, noise-canceling system de-noising effect of the present invention is better, has reduced the limitation of counterpart's ear applying degree of tightness when noise-canceling system uses.
[embodiment]
The invention will be further described below in conjunction with drawings and embodiments.
When the product of utilization de-noising assembly correlation technique in use, it can produce coupling effect when fitting with people's ear, pressure is big more, fits tightly more, the sound that people's ear receives is just big more; Pressure is more little, fits loosely more, and the sound that people's ear receives is just more little.Yet the various parameters of correlation technique de-noising assembly are fixed, and therefore, the de-noising assembly of correlation technique only just can have de-noising effect preferably in certain location.The present invention has promptly designed a kind of de-noising assembly at the problems referred to above, its can be by test utilization the technology of the present invention product and people's ear between the elasticity of fitting adjust the output gain of loud speaker, promptly control the multiplication factor of voice signal output, can de-noising effect be adjusted to perfect condition according to the diverse location of product and people's ear when making the product use of correlation technique.Specific as follows:
As shown in Figure 1, a kind of de-noising assembly 10, it comprise receive microphone 1, loud speaker 5, will receive Noisy Speech Signal that microphone 1 receives and carry out denoising Processing and export de-noising after voice signal signal processing unit 3 and voice signal after the de-noising is amplified and exports the signal amplification unit 4 of amplification voice signal.Wherein, de-noising assembly 10 also is provided with:
Preceding microphone 2 is used to receive detectable signal and feedback signal is surveyed in output;
Development board 6 comprises the processing unit able to programme 62 and the signal generating unit 61 that sends detectable signal that the detection feedback signal of preceding microphone 2 outputs are carried out analyzing and processing and output dc voltage;
Adder unit 7 is used for described amplification voice signal and detectable signal are carried out the signal stack, and output stack back voice signal is input to loud speaker 5.
The present invention also provides a kind of noise-eliminating method of the assembly of de-noising as described in the present invention 10, and this method comprises the steps:
Step 001, establish some test points, utilize to receive microphone 1 and receive extraneous Noisy Speech Signal at test point place arbitrarily, described Noisy Speech Signal obtains voice signal after the de-noising through the processing of signal processing unit 4; Voice signal obtains amplifying voice signal through behind the signal amplification unit 4 after the de-noising, the multiplication factor that direct voltage by 62 outputs of manual adjustments processing unit able to programme changes signal amplification unit 4 makes described amplification voice signal reach perfect condition, obtains the dc voltage value of the multiplication factor correspondence of signal amplification unit 4 this moment.
Signal generating unit 61 by development board 6 sends the detectable signal of fixed frequency and exports to loud speaker 5, and loud speaker 5 sends sync response after receiving described detectable signal; Microphone 2 receives described sync response and exports corresponding the detection and feeds back signal to processing unit 62 able to programme before utilizing; Utilize 62 pairs of described detection feedback signals of processing unit able to programme to do the fft analysis processing and obtain the FFT value.Wherein, FFT is a fast fourier transform.
So-called perfect condition, be meant that in the present embodiment the frequency response curve that amplifies voice signal reaches minimum, promptly amplify the frequency response curve of voice letter with the tester monitoring, change the multiplication factor of signal amplification unit 4 by the direct voltage that does not stop to regulate processing unit 62 outputs able to programme, make the frequency response curve that is presented on the tester be transferred to extreme lower position, refer to promptly that described amplification voice signal has reached perfect condition this moment.
Step 002, at different test point repeating steps 001, obtain some groups of FFT values and dc voltage value.Different test points is to establish according to the variable in distance principle that receives microphone 1 and sound source to get, and it is all different with the distance of sound source that promptly each test point place receives microphone 1.
Step 003, be abscissa with the FFT value, dc voltage value is that ordinate is set up coordinate system, and some groups of FFT values are drawn in coordinate system with corresponding dc voltage value, draws the modulation relational expression of FFT value and direct voltage by described coordinate system.
In the present embodiment, concrete, the FFT value is made as x, described dc voltage value is made as y, with described FFT value is abscissa, dc voltage value is that ordinate is set up coordinate system, some groups of FFT values are drawn in coordinate system with corresponding dc voltage value and is joined end to end successively, draws the corresponding FFT value and the universal relation formula of direct voltage according to the line graph that obtains in the coordinate system.
Get 7 test points in the present embodiment and do analysis, be respectively A1-A7.7 test points are all in the normal range of operation of de-noising assembly 10.In order to improve accuracy, present embodiment is done 7 tests to each test point, averages data that described test point records such as following table again:
Table one
FFT mean value is in 7 test datas of each test point in the last table, averages after removing minimum and maximum value again.
As shown in Figure 2, from figure, get line graph.Line graph described in the present embodiment can be approximately two sections straight lines, A1, A2 and A3 connect into article one straight line, A4, A5, A6 and A7 are linked to be the second straight line, and every section all available linear equation of straight line is represented, the universal relation formula that promptly draws FFT value and direct voltage is as follows:
y=a*x+b (1)
Wherein, a is that amplification coefficient is established, and b is a modifying factor.
Certainly, the coordinate system difference of foundation, the test point of getting not simultaneously, the universal relation formula that it obtains is not to be orthoscopic yet, may be other expression formula, but its principle is the same yet.
FFT value and the described universal relation formula of corresponding dc voltage value substitution (1) that any two test points are obtained, obtain amplification coefficient a and modifying factor b, described amplification coefficient a and the described universal relation formula of obtaining of modifying factor b substitution (1) drawn the modulation relational expression.
When being adjacent to people's ear because of the normal use of considering de-noising assembly 10 of the present invention, the people is 3-15N to the pressure limit of de-noising assembly 10, the scope of the FFT value of voice signal is 50-300 after its corresponding de-noising, all carries out in de-noising assembly normal range of operation when therefore testing.
On the straight line of different sections, get the value that two described universal relation formulas of test point substitution (1) draw a, b in the present embodiment respectively:
With a, the value of b described universal relation formula of generation (1) draws modulation relational expression (2), and is as follows:
In fact, because human error and systematic error, test point is selected not simultaneously, and the data of testing have change, but this all is the error that allows, and can't influence the service behaviour of noise-canceling system, and its principle all is the same.
Step 004, provide a program read write line (figure does not look), utilize described program read write line described modulation relational expression to be write the processing unit able to programme 62 of development board 6.Wherein, the program read write line can be the device of computer or other read-write program of programming.
Step 005, the signal generating unit 61 by described development board 6 send the detectable signal of fixed frequency and export to loud speaker 5, and loud speaker 5 sends sync response after receiving described detectable signal.
Step 006, the described sync response and the corresponding detection of output that utilize preceding microphone 2 reception loud speakers 5 to send feed back signal to processing unit 62 able to programme;
Step 007, utilize 62 pairs of described detection feedback signals of processing unit able to programme to make the direct voltage that fft analysis is handled and output is corresponding.Concrete, processing unit 62 bases able to programme are exported the direct voltage of the multiplication factor of corresponding control signal amplifying unit 4 after writing and wherein modulating relational expression (2) computing, and then adjust the multiplication factor of signal amplification unit 4.In fact, in the de-noising assembly 10 of the present invention, the adjustment of the multiplication factor of 6 pairs of signal amplification units 4 of development board is instant dynamic processes, when promptly surveying the variation that feedback signal do not stop, development board 4 is handled the direct voltage of back output also in the variation that does not stop, and then makes multiplication factor not stop to change.
Step 008, utilization receive microphone 1 and receive extraneous Noisy Speech Signal and be input to signal processing unit 3, the 3 pairs of Noisy Speech Signals of signal processing unit are handled voice signal after the output de-noisings of back, amplify and exports the amplification voice signal by voice signal after 4 pairs of described de-noisings of signal amplification unit.The amplification voice signal of this moment promptly amplifies after adjusting multiplication factor.Input to loud speaker 5 after utilizing adder unit 7 with described amplification language signal and detectable signal stack.
In the present embodiment, the detectable signal that signal generating unit 61 sends is a 250Hz pure-tone pulse signal.Because use low frequency signal to do detectable signal de-noising effect is more optimized, be the more important thing is that people's ear is insensitive to the low frequency signal as 250Hz, the people is not easy to discover, and has avoided the audiovisual illusion.Certainly, the frequency of detectable signal is not limited to 250Hz, also can be other frequency values, but best be to use low-frequency range.
Multiplication factor for voice signal after 4 pairs of de-noisings of control signal amplifying unit accurately, the time interval that microphone 2 receives described detectable signal before in the present embodiment equated with the time interval that signal generating unit 61 sends described detectable signal, and the duration that preceding microphone 2 receives described detectable signal is the twice that signal generating unit 61 sends the duration of described detectable signal.More excellent, the time interval that signal generating unit 61 sends described detectable signal is 1s, the duration of at every turn sending described detectable signal is 10ms; The time interval that preceding microphone 2 receives described detectable signal is 1s, and the duration that at every turn receives described detectable signal is 20ms.The time interval that receives and send described detectable signal in fact is not to be 1s, can be worth for other, and as 2s, in order to ensure de-noising accuracy really, optimal value all can between 1-10s.The duration that preceding microphone 2 receives described detectable signal also can be for other be worth, and optimal value all can between 10-20ms.
Compare with correlation technique, the amplifying parameters of signal amplification unit is set to adjustable in the de-noising assembly of the present invention, increase and be provided with the development board that is used for control signal amplifying unit multiplication factor, send the direct voltage of the multiplication factor of control signal amplifying unit when the product of measuring correlation technique by development board uses with after the elasticity of people's ear applying, thereby adjust multiplication factor immediately, make that the de-noising effect of relative technological products is better.
Above-described only is embodiments of the present invention, should be pointed out that for the person of ordinary skill of the art at this, under the prerequisite that does not break away from the invention design, can also make improvement, but these all belongs to protection scope of the present invention.