CN103389155B - Digital image generation method of three-dimensional spatial distribution of sound quality objective parameters - Google Patents

Abstract

A digital image generation method of three-dimensional spatial distribution of sound quality objective parameters is performed according to the following steps of step1, recording holographic sound pressure data on the holographic measurement surface through a microphone array; step 2, performing acoustic amount reconstruction on a three-dimensional sound field; step 3, calculating the three-dimensional spatial distribution of the sound quality objective parameters such as loudness, sharpness and roughness of every point according to a sound pressure and sound quality objective parameter mapping model and obtained acoustic amount information in a three-dimensional space and providing in the form of a three-dimensional digital image to achieve three-dimensional spatial visualization of the sound quality objective parameters.

Description

Sound quality objective parameter three-dimensional spatial distribution digital image generation method

Technical field:

The present invention relates to Nearfield acoustic holography, identification of sound source location technology, sound field visualization technique, the measurement assessment technique of the objective parameter of sound quality and noise control technique.

Background technology:

Traditional Noise measarement is all to reduce the sound pressure level of sound field response for main target, and result of study shows that the reduction of sound pressure level can not substantially improve the subjective auditory perception of people to sound.Noise is not only relevant with sound pressure level for the impact of people, also form with the frequency of sound, the physical characteristics of human auditory system and psychological characteristic relevant.The difference that two kinds of sound of same sound pressure level forms due to respective frequency, the greatest differences of people's loudness on mental impression can be caused, therefore the evaluation for noise needs introducing can reflect quantizating index-sound quality that people experiences sound subjectivity and objectivity, as the reference to noise rating.

The present invention is applied to the space orientation of visual and the closest with the people's auditory perception sound source of sound quality objective parameter distribution in three-dimensional sound field.When existing sound attributional analysis and measuring method carry out sound quality evaluation to the sound in specified three-dimensional space, the objective parameter information of sound quality of a certain measuring position of specifying in three dimensions can only be obtained, distribution and the visual image of sound quality information in whole three dimensions can not be obtained, thus not only can not evaluate the sound quality quality of whole Enclosed Sound Field, more can not provide the locus with the sound source of sound correlation of attributes.

Summary of the invention:

The present invention will overcome its own shortcomings of prior art: 1. overcome and be used alone the objective parameter measurement of existing sound quality, computational analysis and evaluation method and technology, sound quality profile in whole three dimensions and visual image can not be provided by one-shot measurement, the defect of the sound source position information relevant to the objective parameter of sound quality can not be provided.2. overcome the subjective auditory perception factor not considering people when adopting separately the distribution of near field acoustic holography methods analyst Enclosed Sound Field, the defect with the closely-related sound source position of the subjective auditory perception of people in sound field can not be provided.The invention provides the sound quality objective parameter three-dimensional digital image generation method that near field acoustic holography method combines with sound quality objective parametric analysis method.

The sound quality objective parameter three-dimensional digital image generation method that the present invention proposes, its result of calculation is while providing sound-filed simulation, also can provide and affect the maximum sound source spatial positional information of the subjective auditory perception of people, and the image of the objective parameter of sound quality in whole three dimensions distribution is provided, thus provides visual, the most directly instruct for noise reduction harmony quality improving.

The present invention carries out as follows:

1. utilize the holographic acoustic pressure data in microphone array (microphone array can be the spherical microphone array of rigid surface, hollow ball array, the microphone array conformal with sound source structure or planar array) recording holographic measuring surface.

Arrange spherical microphone array at Enclosed sound field, measure and record sound field sound pressure information.Holographic acoustic pressure data is obtained at open and semi-open sound field feasible planes microphone array and the conformal microphone array of other arbitrary shape.

2. three-dimensional sound field acoustics amount reconstruct

According to the holographic acoustic pressure data measured, obtained the distributed intelligence (acoustic pressure, normal direction particle rapidity and the normal direction sound intensity etc.) of Enclosed Sound Field acoustics amount by near field acoustic holography method, and provide with the form of 3-D view.

The holographic acoustic pressure adopting spherical microphone array to measure carrys out the acoustics amount distribution in Reconstruction of three-dimensional space, and sound field transformation for mula is as follows:

$p_t(r,\mathrm{\θ},\mathrm{\φ},\mathrm{\ω})\≈\underset{n=0}{\overset{N}{\mathrm{\Σ}}}(j_n\left(\mathrm{kr}\right)-\frac{j_n^{\′}\left(\mathrm{ka}\right)}{h_n^{\′}\left(\mathrm{ka}\right)}{j}_n\left(\mathrm{kr}\right))\underset{m=-n}{\overset{n}{\mathrm{\Σ}}}{A}_{\mathrm{mn}}{Y}_n^m(\mathrm{\θ},\mathrm{\φ})---\left(1\right)$

A in formula _mndetermine by there being following formula:

$A_{\mathrm{mn}}=\frac{{\∫}_0^{2\mathrm{\π}}{\∫}_0^{\mathrm{\π}}{p}_t(a,\mathrm{\θ},\mathrm{\φ})Y_n^m{(\mathrm{\θ},\φ)}^{*}\sin \mathrm{\θd\θd\φ}}{(j_n\left(\mathrm{ka}\right)-\frac{j_n^{\′}\left(\mathrm{ka}\right)}{h_n^{\′}\left(\mathrm{ka}\right)}{h}_n\left(\mathrm{ka}\right))}---\left(2\right)$

In above formula: (r, θ, φ) is the spherical coordinates of three dimensions any point in sound field; A is the radius of spherical microphone array, and k is wave number, and k=ω/c, ω are angular frequency, and c is the velocity of sound, and ω=2 π f, f are frequency.P _t(a, θ, φ) holographic acoustic pressure data for microphone array gathers; p _t(r, θ, φ, ω) is the reconstruct acoustic pressure at three dimensions assigned address (r, θ, φ) place; for spheric harmonic function, j _n(kr) be ball Bessel function, h _n(kr) be ball Hunk function; " * " represents conjugation, " ' " represent derivative, N is spheric harmonic function expansion item number.When specifying the position of Reconstruction of Sound Field point in whole three dimensions, then obtain the acoustic pressure distribution of whole sound field.

3., according to the sound field information in the three dimensions obtained in 2, calculate the distribution of the three dimensions objective parameter of each point sound quality (as loudness, sharpness, roughness etc.), and provide with the form of 3-D view, realize the three-dimensional visualization of the objective parameter of sound quality.

In sound field, single-point sound quality loudness computation model is as follows:

$N_i^{\&prime;}=\left\{\begin{array}{cc}C[{(G{E}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_{\mathrm{THRQ}}<E_i<{10}^{10}\\ C\left(\frac{2E_i}{E_i+E_{\mathrm{THRQ}}}\right)[{(G{E}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_i<E_{\mathrm{THRQ}}\\ C{\left(\frac{E_i}{1.0707}\right)}^{0.2}& E_i>{10}^{10}\end{array}\right.---\left(3\right)$

N ' in above formula _ibe the characteristic loudness of i-th wave filter, E _tHRQfor valve energy level can be listened, E _ifor the energy level of signal, unit is dB, and C is definite value 0.046871, works as f _iduring >500Hz, E _tHRQfor definite value 2.3067, cochlea low-frequency gain G is 1, α is 0.2, and works as f _iduring <500Hz, E _tHRQ, the discrete attributes that α all can provide according to ANSI calculates and obtains.G is cochlea low-frequency gain.Therefore total loudness formula is:

$N=0.2\underset{i=1}{\overset{372}{\mathrm{\&Sigma;}}}{N}_i^{\&prime;}---\left(4\right)$

According to the three-dimensional spatial distribution result of acoustic pressure in the sound field calculated in 2, and in conjunction with the computation model of the objective parameter of single-point sound quality in space, set up the three-dimensional matrice mapping model that is coupled of sonic pressure field and loudness field in space, that is:

${[p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_1)\&CenterDot;\&CenterDot;p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_m)]}_{1\&times;m}{\left[\begin{array}{ccc}{w}_1& \&CenterDot;\&CenterDot;& w_{372}\\ w_1& \&CenterDot;\&CenterDot;& w_{372}\\ \&CenterDot;& \&CenterDot;\&CenterDot;& \&CenterDot;\\ w_1& \&CenterDot;\&CenterDot;& w_{372}\end{array}\right]}_{m\&times;372}={[N_1^{\&prime;}(r,\mathrm{\&theta;},\mathrm{\&phi;})\&CenterDot;\&CenterDot;N_{372}^{\&prime;}(r,\mathrm{\&theta;},\mathrm{\&phi;})]}_{1\&times;372}---\left(5\right)$

Or be abbreviated as:

P _iW=N′ (6)

In formula: (r, θ, φ) is the spherical coordinates of three dimensions i-th, ω _mfor angular frequency, ω _m=2 π f _m, f _mfor frequency, m=1,2 ... M, M be different sound source corresponding frequency composition number.P _ifor the acoustic pressure under i-th arbitrary frequency in place in sound field, P _ifor the vector that the acoustic pressure reconstruction value under i-th each frequency in place in sound field forms, W is the auditory filter matrix be made up of 372 wave filter w, and represent that people's ear is to the response of frequencies all in audio-band, N ' is characteristic loudness vector.Just can be obtained the loudness of sound field specified point by formula (4) to the every summation in characteristic loudness vector N ', and this computation process is repeated to sound field three dimensions node just can obtain sound field loudness distributed in three dimensions result.Other sound quality objective amount distributed in three dimensions result also can adopt and calculate similar analysis process with loudness and obtain, and sees accompanying drawing 1.

Can be provided the objective value of consult volume of sound quality of each position in detected space by said method, and provide its space distribution with the form of 3-D view, and then identifiable design goes out the sound source position had the greatest impact to the subjective sense of hearing of people.

Accompanying drawing illustrates:

Fig. 1. the calculation flow chart of the objective parameter distributed in three dimensions of sound quality of the present invention

Fig. 2. spherical microphone array schematic diagram

Fig. 3. spherical microphone array and double sound source sound-filed simulation schematic diagram

The loudness of Fig. 4 (a) .3.5kHz (69dB) and 1kHz (75dB) two point sound source sound field and the contrast of acoustic pressure result of calculation

The sharpness of Fig. 4 (b) .3.5kHz (69dB) and 1kHz (75dB) two point sound source sound field and the contrast of acoustic pressure result of calculation

The loudness of Fig. 4 (c) .3.5kHz (70dB) and 7kHz (76dB) two point sound source sound field and the contrast of acoustic pressure result of calculation

The sharpness of Fig. 4 (d) .3.5kHz (70dB) and 7kHz (76dB) two point sound source sound field and the contrast of acoustic pressure result of calculation

Specific embodiments:

Below by specific embodiment, the invention will be further described.With reference to accompanying drawing:

The sound quality objective parameter three-dimensional digital image generation method that the present invention proposes, its result of calculation is while providing sound-filed simulation, also can provide and affect the maximum sound source spatial positional information of the subjective auditory perception of people, and the image of the objective parameter of sound quality in whole three dimensions distribution is provided, thus provides visual, the most directly instruct for noise reduction harmony quality improving.

The present invention carries out as follows:

1. utilize the holographic acoustic pressure data in microphone array (microphone array can be the spherical microphone array of rigid surface, hollow ball array, the microphone array conformal with sound source structure or planar array) recording holographic measuring surface.

Arrange spherical microphone array at Enclosed sound field, measure and record sound field sound pressure information.Holographic acoustic pressure data is obtained at open and semi-open sound field feasible planes microphone array and the conformal microphone array of other arbitrary shape.

2. three-dimensional sound field acoustics amount reconstruct

According to the holographic acoustic pressure data measured, obtained the distributed intelligence (acoustic pressure, normal direction particle rapidity and the normal direction sound intensity etc.) of Enclosed Sound Field acoustics amount by near field acoustic holography method, and provide with the form of 3-D view.

The holographic acoustic pressure adopting spherical microphone array to measure carrys out the acoustics amount distribution in Reconstruction of three-dimensional space, and sound field transformation for mula is as follows:

$p_t(r,\mathrm{\&theta;},\mathrm{\&phi;},\mathrm{\&omega;})\&ap;\underset{n=0}{\overset{N}{\mathrm{\&Sigma;}}}(j_n\left(\mathrm{kr}\right)-\frac{j_n^{\&prime;}\left(\mathrm{ka}\right)}{h_n^{\&prime;}\left(\mathrm{ka}\right)}{j}_n\left(\mathrm{kr}\right))\underset{m=-n}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{\mathrm{mn}}{Y}_n^m(\mathrm{\&theta;},\mathrm{\&phi;})---\left(1\right)$

A in formula _mndetermine by there being following formula:

$A_{\mathrm{mn}}=\frac{{\&Integral;}_0^{2\mathrm{\&pi;}}{\&Integral;}_0^{\mathrm{\&pi;}}{p}_t(a,\mathrm{\&theta;},\mathrm{\&phi;})Y_n^m{(\mathrm{\&theta;},\&phi;)}^{*}\sin \mathrm{\&theta;d\&theta;d\&phi;}}{(j_n\left(\mathrm{ka}\right)-\frac{j_n^{\&prime;}\left(\mathrm{ka}\right)}{h_n^{\&prime;}\left(\mathrm{ka}\right)}{h}_n\left(\mathrm{ka}\right))}---\left(2\right)$

In above formula: (r, θ, φ) is the spherical coordinates of three dimensions any point in sound field; A is the radius of spherical microphone array, and k is wave number, and k=ω/c, ω are angular frequency, and c is the velocity of sound, and ω=2 π f, f are frequency.P _t(a, θ, φ) holographic acoustic pressure data for microphone array gathers; p _t(r, θ, φ, ω) is the reconstruct acoustic pressure at three dimensions assigned address (r, θ, φ) place; for spheric harmonic function, j _n(kr) be ball Bessel function, h _n(kr) be ball Hunk function; " * " represents conjugation, " ' " represent derivative, N is spheric harmonic function expansion item number.When specifying the position of Reconstruction of Sound Field point in whole three dimensions, then obtain the acoustic pressure distribution of whole sound field.

3., according to the sound field information in the three dimensions obtained in 2, calculate the distribution of the three dimensions objective parameter of each point sound quality (as loudness, sharpness, roughness etc.), and provide with the form of 3-D view, realize the three-dimensional visualization of the objective parameter of sound quality.

In sound field, single-point sound quality loudness computation model is as follows:

$N_i^{\&prime;}=\left\{\begin{array}{cc}C[{(G{E}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_{\mathrm{THRQ}}<E_i<{10}^{10}\\ C\left(\frac{2E_i}{E_i+E_{\mathrm{THRQ}}}\right)[{(G{E}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_i<E_{\mathrm{THRQ}}\\ C{\left(\frac{E_i}{1.0707}\right)}^{0.2}& E_i>{10}^{10}\end{array}\right.---\left(3\right)$

N ' in above formula _ibe the characteristic loudness of i-th wave filter, E _tHRQfor valve energy level can be listened, E _ifor the energy level of signal, unit is dB, and C is definite value 0.046871, works as f _iduring >500Hz, E _tHRQfor definite value 2.3067, cochlea low-frequency gain G is 1, α is 0.2, and works as f _iduring <500Hz, E _tHRQ, the discrete attributes that α all can provide according to ANSI calculates and obtains.G is cochlea low-frequency gain.Therefore total loudness formula is:

$N=0.2\underset{i=1}{\overset{372}{\mathrm{\&Sigma;}}}{N}_i^{\&prime;}---\left(4\right)$

According to the three-dimensional spatial distribution result of acoustic pressure in the sound field calculated in 2, and in conjunction with the computation model of the objective parameter of single-point sound quality in space, set up the three-dimensional matrice mapping model that is coupled of sonic pressure field and loudness field in space, that is:

${[p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_1)\&CenterDot;\&CenterDot;p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_m)]}_{1\&times;m}{\left[\begin{array}{ccc}{w}_1& \&CenterDot;\&CenterDot;& w_{372}\\ w_1& \&CenterDot;\&CenterDot;& w_{372}\\ \&CenterDot;& \&CenterDot;\&CenterDot;& \&CenterDot;\\ w_1& \&CenterDot;\&CenterDot;& w_{372}\end{array}\right]}_{m\&times;372}={[N_1^{\&prime;}(r,\mathrm{\&theta;},\mathrm{\&phi;})\&CenterDot;\&CenterDot;N_{372}^{\&prime;}(r,\mathrm{\&theta;},\mathrm{\&phi;})]}_{1\&times;372}---\left(5\right)$

Or be abbreviated as:

P _iW=N′ (6)

In formula: (r, θ, φ) is the spherical coordinates of three dimensions i-th, ω _mfor angular frequency, ω _m=2 π f _m, f _mfor frequency, m=1,2 ... M, M be different sound source corresponding frequency composition number.P _ifor the acoustic pressure under i-th arbitrary frequency in place in sound field, P _ifor the vector that the acoustic pressure reconstruction value under i-th each frequency in place in sound field forms, W is the auditory filter matrix be made up of 372 wave filter w, and represent that people's ear is to the response of frequencies all in audio-band, N ' is characteristic loudness vector.Just can be obtained the loudness of sound field specified point by formula (4) to the every summation in characteristic loudness vector N ', and this computation process is repeated to sound field three dimensions node just can obtain sound field loudness distributed in three dimensions result.Other sound quality objective amount distributed in three dimensions result also can adopt and calculate similar analysis process with loudness and obtain, and sees accompanying drawing 1.

In the present embodiment, all using ball array as measurement battle array, as shown in Figure 2, on sphere, non-uniform Distribution 36 microphones, and the spacing between microphone is not etc.

1. as shown in Figure 3, arrange two pulsation ball sources in space: the optimum configurations of sound source 1 is 1kHz, 75dB, 0.3m place (0.3m, 0,0) in the x positive axis being placed on rectangular coordinate system in space; The optimum configurations of sound source 2 is 3.5kHz, 69dB, and the x being placed on rectangular coordinate system in space bears 0.3m place on semiaxis (-0.3m, 0,0), and the angle theta namely between two sound sources is 180 °, and the radius a of spherical microphone array (as Fig. 2) is 0.1m.The computing method adopting the present invention to provide reconstruct the three-dimensional spatial distribution figure of acoustic pressure, loudness and the sharpness that radius is 0.2m place.Fig. 4 (a) is the comparison diagram of the three-dimensional spatial distribution result of calculation of acoustic pressure when simultaneously existing of the sound source 1 of 1kHz, 75dB and sound source 2 liang of sound sources of 3.5kHz, 69dB and loudness.Fig. 4 (b) is the comparison diagram of the three-dimensional spatial distribution result of calculation of acoustic pressure when simultaneously existing of the sound source 1 of 1kHz, 75dB and sound source 2 liang of sound sources of 3.5kHz, 69dB and sharpness.

2. adopt the double sound source sound-field model described in 1 equally, but the optimum configurations of sound source 1 is 7kHz, 70dB, 0.3m place (0.3m, 0,0) in the x positive axis being placed on rectangular coordinate system in space; The optimum configurations of sound source 2 is 3.5kHz, 76dB, and the x being placed on rectangular coordinate system in space bears 0.3m place on semiaxis (-0.3m, 0,0), and the angle theta between two sound sources is still 180 °.Fig. 4 (c) and Fig. 4 (d) are the comparison diagram of the three-dimensional spatial distribution result of calculation of the sound source 1 of 7kHz, 70B and sound source 2 liang of sound sources of 3.5kHz, 76dB adopt this method to reconstruct acoustic pressure, loudness and sharpness that radius is the sphere at 0.2m place respectively.

The result that the above-mentioned figure of comparative analysis provides, identify that the acoustical holography method of localization of sound source is different from tradition according to acoustic pressure, method provided by the invention can obtain the three-dimensional spatial distribution information of the objective parameter of sound quality of sound field, and identify and the closely-related sound source position information of the subjective sense of hearing of people, Fig. 4 gives the three-dimensional spatial distribution figure of the objective parameter of the sound such as loudness and sharpness quality, achieve the auditory localization of the subjective auditory perception according to people, comparison diagram 4 (a) and Fig. 4 (b), Fig. 4 (c) and Fig. 4 (d), can find that the locus maximum with loudness, the maximum locus of acoustic pressure is not identical, and the locus maximum with sharpness, the maximum locus of loudness is not identical yet.Therefore, to take appropriate measures really could realize the object of sound field noise reduction harmony quality improving according to the locator key sound source of the subjective auditory perception of people.

Claims (1)

1. sound quality objective parameter three-dimensional spatial distribution digital image generation method, carry out as follows:

Step 1. utilizes microphone array, and microphone array can be one of following four: the spherical microphone array of rigid surface, hollow ball array, the microphone array conformal with sound source structure or planar array, the holographic acoustic pressure data in recording holographic measuring surface;

In closing, sound field arranges spherical microphone array, measures and records the acoustics amount information such as the holographic acoustic pressure of sound field; Holographic acoustic pressure data is obtained at open and semi-open sound field feasible planes microphone array and the conformal microphone array of other arbitrary shape;

Step 2. three-dimensional sound field acoustics amount reconstructs

According to the holographic acoustic pressure data measured, obtained the distributed intelligence of Enclosed Sound Field acoustics amount by near field acoustic holography method, described distributed intelligence refers to acoustic pressure, normal direction particle rapidity and the normal direction sound intensity, and provides with the form of 3-D view;

The holographic acoustic pressure measured as adopted spherical microphone array carrys out the acoustics amount distribution in Reconstruction of three-dimensional space, and sound field transformation for mula is as follows:

$p_t(r,\mathrm{\&theta;},\mathrm{\&phi;},\mathrm{\&omega;})\&ap;\underset{n=0}{\overset{N}{\mathrm{\&Sigma;}}}(j_n\left(\mathrm{kr}\right)-\frac{j_n^{\text{'}}\left(\mathrm{ka}\right)}{h_n^{\text{'}}\left(\mathrm{ka}\right)}{j}_n\left(\mathrm{kr}\right))\underset{m=-n}{\overset{n}{\mathrm{\&Sigma;}}}{A}_{\mathrm{mn}}{Y}_n^m(\mathrm{\&theta;},\mathrm{\&phi;})---\left(1\right)$

A in formula _mndetermine by there being following formula:

$A_{\mathrm{mn}}=\frac{{\&Integral;}_0^{2\mathrm{\&pi;}}{\&Integral;}_0^{\mathrm{\&pi;}}{p}_t(a,\mathrm{\&theta;},\mathrm{\&phi;})Y_n^m{(\mathrm{\&theta;},\mathrm{\&phi;})}^{*}\sin \mathrm{\&theta;d\&theta;d\&phi;}}{(j_n\left(\mathrm{ka}\right)-\frac{j_n^{\text{'}}\left(\mathrm{ka}\right)}{h_n^{\text{'}}\left(\mathrm{ka}\right)}{h}_n\left(\mathrm{ka}\right))}---\left(2\right)$

In above formula: (r, θ, φ) is the spherical coordinates of three dimensions any point in sound field; A is the radius of spherical microphone array, and k is wave number, and k=ω/c, ω are angular frequency, and c is the velocity of sound, and ω=2 π f, f are frequency; p _t(a, θ, φ) holographic acoustic pressure data for microphone array gathers; p _t(r, θ, φ, ω) is the reconstruct acoustic pressure at three dimensions assigned address (r, θ, φ) place; for spheric harmonic function, j _n(kr) be ball Bessel function, h _n(kr) be ball Hunk function; " * " represents conjugation, " ' " represent derivative, N is spheric harmonic function expansion item number; When specifying the position of Reconstruction of Sound Field point in whole three dimensions, then obtain the acoustic pressure distribution of whole sound field;

Step 3., according to the acoustic pressure distribution in the three dimensions obtained in step 2, calculates the distribution of the objective parameter of three dimensions each point sound quality, and provides with the form of 3-D view, realize the three-dimensional visualization of the objective parameter of sound quality;

In sound field, single-point sound quality loudness computation model is as follows:

$N_i^{\text{'}}=\left\{\begin{array}{cc}C[{({\mathrm{GE}}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_{\mathrm{THRQ}}<E_i<{10}^{10}\\ C\left(\frac{2E_i}{E_i+E_{\mathrm{THRQ}}}\right)[{({\mathrm{GE}}_i+2E_{\mathrm{THRQ}})}^{\mathrm{\&alpha;}}-{\left(2E_{\mathrm{THRQ}}\right)}^{\mathrm{\&alpha;}}]& E_i<E_{\mathrm{THRQ}}\\ C{\left(\frac{E_i}{1.0707}\right)}^{0.2}& E_i>{10}^{10}\end{array}\right.---\left(3\right)$

N in above formula _i' be the characteristic loudness of i-th wave filter, E _tHRQfor valve energy level can be listened, E _ifor the energy level of signal, unit is dB, and C is definite value 0.046871, works as f _iduring >500Hz, E _tHRQfor definite value 2.3067, cochlea low-frequency gain G is 1, α is 0.2, and works as f _iduring <500Hz, E _tHRQ, the discrete attributes that α all can provide according to ANSI calculates and obtains; G is cochlea low-frequency gain; Therefore total loudness formula is:

$N=0.2\underset{i=1}{\overset{372}{\mathrm{\&Sigma;}}}{N}_i^{\text{'}}---\left(4\right)$

According to the three-dimensional spatial distribution result of acoustic pressure in the sound field calculated in step 2, and in conjunction with the computation model of the objective parameter of single-point sound quality in space, set up being coupled of sonic pressure field and loudness field in space, matrix mapping model is:

$[p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_1)..p_i(r,\mathrm{\&theta;},\mathrm{\&phi;},{\mathrm{\&omega;}}_m){]}_{1\&times;m}{\left[\begin{array}{ccc}{w}_1& ..& w_{372}\\ w_1& ..& w_{372}\\ .& ..& .\\ w_1& ..& w_{372}\end{array}\right]}_{m\&times;372}={[N_1^{\&prime;}(r,\mathrm{\&theta;},\mathrm{\&phi;})..N_{372}^{\text{'}}(r,\mathrm{\&theta;},\mathrm{\&phi;})]}_{1\&times;372}---\left(5\right)$

Or be abbreviated as:

P _iW＝N′ (6)

In formula: (r, θ, φ) is the spherical coordinates of three dimensions i-th, ω _mfor angular frequency, ω _m=2 π f _m, f _mfor frequency, m=1,2 ... M, M be different sound source corresponding frequency composition number; p _ifor the acoustic pressure under i-th place's assigned frequency in sound field, P _ifor the vector that the acoustic pressure reconstruction value under i-th each frequency in place in sound field forms, W is the auditory filter matrix be made up of 372 wave filter w, and represent that people's ear is to the response of frequencies all in audio-band, N ' is characteristic loudness vector; Just can be obtained the loudness of sound field specified point by formula (4) to the every summation in characteristic loudness vector N ', and this computation process is repeated to sound field three dimensions node just can obtain sound field loudness distributed in three dimensions result.