KR100995120B1 - System and Method for measuring indoor sound - Google Patents

Abstract

The present invention relates to a system and method for measuring indoor acoustics, comprising: an acoustic characteristic data generator configured to obtain an impulse response by convolving an audio signal input from a microphone with a reference signal, and an impulse response generated by the acoustic characteristic data generator for each band A filtering unit for filtering, a non-diffusing sound field analyzer for obtaining the attenuation rate of each section using regression analysis on the first to third sections of the band-specific impulse response generated by the filtering unit, and outputting the results from the non-diffusing sound field analysis unit It is possible to measure and display the sound decay rate similar to the reverberation time in the non-diffusion space where the measurement of the reverberation time is impossible.

Acoustic, Audio, Impulse Response, Diffusion Sound Field, Non-Diffuse Sound Field, Attenuation Rate, Regression Analysis

Description

System and Method for measuring indoor sound

 The present invention relates to an indoor acoustic measurement system and method, and more particularly, a first section in which a sound level falls by 5 dB to 15 dB using an impulse response in a non-proliferative space in which reverberation time cannot be measured. The present invention relates to a room acoustic measurement system and method capable of measuring and displaying attenuation rates similar to reverberation time by obtaining attenuation rates for two sections and a third section falling from 25 dB to 35 dB.

In general, the sound generated in a certain place may be perceived differently by the listener depending on the size of the space, the sound absorption rate of the material constituting the wall, floor, and ceiling, the sound source, and the variable position of the listener. Can be.

If you can't hear the clear sound in an indoor space such as a lecture room or a conference room, you are not satisfied with the function of the room. An important acoustic factor that allows you to hear clear sound in an indoor space is the 'damping rate'.

Attenuation rate is defined as the time it takes for a sound to disappear after it is generated in the room, whether it is a voice or a musical instrument. In a very ringing space, such as a cathedral, the tail of the sound lasts long and the attenuation rate is very low. In recording studios, there is almost no sound, and the attenuation rate is very high. In spaces with long tails, that is, low attenuation rates, the front sound of a word or sentence interferes with the correct hearing of subsequent back sounds, making it impossible to hear clearly.

Reverberation time is a standard specified by the international standard (ISO 3382 / ISO 3382-2) and the Korean standard (KS F 2864) to quantitatively indicate the degree of sound attenuation. Reverberation time is defined as the time taken for the sound energy of sound generated in an indoor space to fall to the first millionth level. The decibel scale used in acoustic technology is the time it takes for the sound level to drop by 60 dB. In other words, if the sound first generated was 100 dB, the time until the sound dropped to 40 dB was measured and displayed as the reverberation time of the room. The reverberation time is longer when the room is larger, and the lower the sound absorption rate (absorption rate of sound energy: depending on the material / process) of finishing materials such as walls and ceilings.

The most important assumption of the principle of calculating and measuring this reverberation time is the diffuse sound field. Diffusion sound field assumes that when sound is generated in a room, it is heard in the same size at any place in the room. The farther the sound is from, the smaller it sounds, so it's obviously not 100% true, but there's no better way to use it.

The second assumption of reverberation time is 'continuous attenuation', which means that over time the sound energy is attenuated at an equal rate. However, sound energy is much more attenuated when it hits walls or ceilings than when it travels through space.

 In particular, when the sound absorption rate of walls and ceilings is high, 'intermittent sound attenuation' occurs, so it is applied even though it is not 100% true.

Although these two important assumptions of reverberation time are not perfect, the reverberation time is still used as an important parameter for room acoustics because the error is not large and no other means have been developed to replace it in reality. The reverberation time is multiplied by 3 by measuring the attenuation rate in the initial -5 dB to -25 dB range on the premise that the attenuation rate is linear (meaning that the sound energy decays at a constant rate with time), or the initial -5 dB to- The attenuation rate of 35dB section is measured and multiplied by 2 (T30).

That is, in theory, the attenuation time of 60 dB should be measured, but the attenuation rate of the entire initial -5 dB to -65 dB range cannot be measured because of the background noise present in any measurement situation. Partial measurement is to use the method.

However, if the space to be measured is a clear non-diffusion sound field, then the assumption of diffuse sound field and continuous attenuation will never be established.

In addition, it is not possible to assume that the loudness of all positions are the same in a large space of 200 meters, and in some cases, no sound can be heard far from the sound source.

In addition, in the case of a non-diffusion sound field in which a part of the room is bent outward, the magnitude of sound energy does not attenuate continuously or linearly, and thus the attenuation rate in the non-diffusion sound field cannot be expressed as the concept of reverberation time.

In addition, the sound attenuation rate cannot be linear in the non-diffusion sound field measurement method. Therefore, the time until the attenuation is proportionately 60 dB by measuring only an initial part such as T20 or T30 should not be calculated.

The present invention has been made to solve the above-described problems, and to provide a room acoustic measurement system and method for measuring the sound reflecting the characteristics of non-diffusion and the status of intermittent attenuation.

Another object of the present invention is to separate the three sections having different attenuation ratios of the initial -5dB to -15dB section (T1), -15dB to -25dB section (T2), -25dB to -35dB section (T3) after the sound is generated. An indoor acoustic measurement system and method for indexing are provided.

According to an aspect of the present invention to achieve the above object, an acoustic characteristic data generation unit for obtaining an impulse response by convolving an audio signal input from a microphone with a reference signal, the band of the impulse response generated by the acoustic characteristic data generation unit A filtering unit for filtering by a non-diffusion sound field analysis unit for obtaining the attenuation rate of each section using regression analysis for the first to third sections of the band-specific impulse response generated by the filtering unit. An indoor acoustic measurement system including an output unit for outputting is provided.

 The indoor acoustic measurement system includes a microphone for generating an audio signal generated by an audio signal generator and receiving an audio signal output through a speaker, a microphone amplifier for amplifying an audio signal input from the microphone, and an analog signal amplified by the microphone amplifier. The apparatus may further include an analog / digital converter which converts the signal into a signal and provides the acoustic characteristic data generator.

The reference signal may be an original audio signal generated by an audio signal generator.

The filtering unit is an octave bandpass filter, and performs filtering on 63Hz, 125Hz, 250Hz, 500Hz, 1KHz, 2KHz, 4KHz, and full bands of the impulse response generated by the acoustic characteristic data generator to perform impulse response for each band. Create

The non-diffusion sound field analyzer calculates sound attenuation rates for the first section in which the sound level falls by 5 dB to 15 dB, the second section in which 15 dB to 25 dB falls, and the third section in which 25 dB to 35 dB falls after the sound is generated for the impulse response for each band.

The attenuation rate is calculated using the slope in each section through the regression analysis.

According to another aspect of the present invention, an acoustic characteristic data generator for convolving an audio signal input from a microphone with a reference signal to obtain an impulse response, a filtering unit for filtering the impulse response generated by the acoustic characteristic data generator for each band; An impulse response analyzer for determining whether or not a non-diffused sound field is analyzed by analyzing the impulse response for each band generated by the filtering unit; and if the non-diffusion sound field is determined as the result of the determination of the impulse response analyzer, In the case of the non-diffusion sound field analyzer which calculates the attenuation rate of each section by using regression analysis for the first to third sections, and the diffusion resulted by the impulse response analyzer, the initial predetermined section is performed for the band-specific impulse response generated by the filtering unit. Diffused sound field analysis unit, the non-diffused sound field analyzer, Is provided with a room acoustic measurement system comprises an output unit for outputting the result of the diffuse sound field analysis unit.

The impulse response analysis unit determines that the impulse response for each band is a non-diffusion sound field when the nonlinear characteristic, and a diffusion sound field when the linear characteristic is a linear characteristic.

The diffusion sound field analysis unit obtains the reverberation time by multiplying the attenuation rate of the section in which the sound level falls by 5 dB to 25 dB after the sound is generated and multiplying it by three or the number 2 by the section in which the sound level falls by 5 dB to 35 dB. .

The acoustic measurement system further includes a microphone amplifier for amplifying an audio signal input from the microphone, and an analog / digital converter for converting an analog signal amplified by the microphone amplifier into a digital signal and providing the digital signal to the acoustic characteristic data generator. do.

According to another aspect of the invention, (a) convoluting the audio signal input from the microphone with a reference signal to obtain an impulse response, (b) filtering the obtained impulse response band by band to generate a band-specific impulse response Step (c) Analyzing the generated band-specific impulse response to determine whether or not the non-diffusion sound field, (d) If the determination result of the step (c) is a non-diffusion sound field, the first to A room acoustic measurement method is provided, the method including calculating attenuation rate using a regression analysis for a third section.

The audio signal input from the microphone includes an original audio signal generated through a speaker, direct sound due to spatial characteristics, initial reflection sound, and reverberation sound.

The present invention can provide a room acoustic measurement system and method that can measure and display the sound attenuation rate of a concept similar to the reverberation time even in a non-diffusion space in which the reverberation time cannot be measured.

In addition, TN (T1, T2, T3) can be used to quantify the degree of acoustic non-diffusion in any space, and if the attenuation rates of the three sections are similar, the indoor acoustic measurement can be interpreted as showing the behavior close to the diffused sound field. Systems and methods can be provided.

In addition, since T1, which shows the initial decay rate, has a greater effect on masking of subsequent sounds such as sentences and words, T1, T2, and T3, in order to increase the speech intelligibility of the non-diffusion sound field. It is possible to provide a room acoustic measurement system and method that can suggest new acoustic indicators to display.

In addition, it is possible to provide an indoor acoustic measurement system and method capable of presenting an index for predicting the situation of indoor acoustics based on the trend of T1, T2, and T3.

Details of the above-described objects and technical configurations of the present invention and the effects thereof according to the present invention will be more clearly understood by the following detailed description based on the accompanying drawings.

1 is a block diagram schematically showing the configuration of an acoustic measurement system of an indoor space according to the present invention.

Referring to FIG. 1, the acoustic measurement system of an indoor space includes a microphone 100 for receiving an audio signal, a microphone amplifier 110 for amplifying an audio signal input from the microphone 100, and the microphone amplifier 110. The analog / digital converter (ADC) 120 converting the analog signal amplified by the digital signal into a digital signal, and the digital signal converted from the analog / digital converter 120 are convolved with a reference signal to generate an impulse response. Obtaining the acoustic characteristic data generation unit 130, the filtering unit 140 for filtering the impulse response generated by the acoustic characteristic data generation unit 130 for each band, the band of the impulse response generated for each band generated by the filtering unit 140 A non-diffusing sound field analysis unit 150 for obtaining a non-diffusion sound field attenuation rate for the first to third sections, and an output unit 160 for outputting a result from the non-diffusion sound field analysis unit 150. do.

The microphone 100 receives an audio signal output through a speaker (not shown) of an audio signal generator (not shown). The audio signal generated by the audio signal generator may be a reference signal used by the acoustic characteristic data generator 130. The audio signal input from the microphone 100 includes an original signal generated by the audio signal generator and direct sound, initial reflection sound, reverberation sound, and the like due to spatial characteristics.

The acoustic characteristic data generator 130 convolves the digital audio signal with the original audio signal generated by the audio signal generator to obtain an impulse response. That is, since the original audio signal generated by the audio signal generator is stored in the acoustic characteristic data generator 130, an impulse response may be obtained by convolving with the digital signal.

An impulse response refers to the ringing of a sound generated in a space. When an impulse is recorded using an impulse, the impulse response is recorded. This impulse response produces less sound in a room such as a recording studio with walls made of high sound absorption. On the other hand, in the auditorium or opera space made of materials with low sound absorption and high reflectivity, the sound is very loud.

The filtering unit 140 is an octave bandpass filter that passes only components of a predetermined band among frequency components of an impulse response generated by the acoustic characteristic data generator 130.

That is, the filtering unit 140 performs impulse response for each band by performing filtering on the 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 KHz, 2 KHz, 4 KHz, and full bands, respectively.

The filtering unit 140 measures levels of individual frequencies to identify sound components.

The non-diffusion sound field analysis unit 150 generates a first period of -5 dB to -15 dB, a second period of -15 dB to -25 dB after sound generation for each band-specific impulse response generated by the filtering unit 140,- For each third section of 25dB to -35dB, find the attenuation rate. The attenuation rate is calculated using the slope in each section through the regression analysis. The first section refers to a section in which the sound level falls by 5 dB to 15 dB after the sound is generated, the second section refers to a section in which the sound level falls by 15 dB to 25 dB, and the third section refers to a section in which the sound level falls by 25 dB to 35 dB.

The decay rate in a non-diffused sound field should not be proportionally extended by measuring only part of the initial attenuation, such as T20 or T30. In the non-diffusion sound field, since nonlinearity occurs from the beginning of the attenuation, the attenuation itself of 20 dB (-5 dB to 25 dB) or 30 dB (-5 dB to -35 dB) cannot be expressed as a linear trend. Even if we calculate by equation, the result can't be extended to 60dB (-5dB ~ -65dB). Therefore, the attenuation rate of the indoor space of the non-diffusion sound field is measured by displaying the initial -5dB to -15dB section (T1), -15dB to -25dB section (T2), and -25dB to -35dB section (T3) separately after the sound is generated.

The acoustic measurement system may quantify the degree of acoustic non-diffusion of a space by utilizing the TNs (T 1, T 2, T 3) obtained as described above. Similar sound attenuation rates in these three sections can be interpreted as showing close to the diffusion sound field, and when T1, T2, and T3 are significantly different, the acoustic non-diffusion of the space is very large. In other words, the degree of non-diffusion of the space can be displayed according to the difference between the three attenuation rates.

2 is a block diagram schematically illustrating a configuration of an acoustic measurement system of an indoor space according to another embodiment of the present invention.

Referring to FIG. 2, a system for measuring attenuation of indoor spaces includes a microphone 200 for receiving an audio signal and a microphone amplifier 210 for amplifying an audio signal input from the microphone 200. ), An analog / digital converter (ADC) 220 for converting the analog signal amplified by the microphone amplifier 210 into a digital signal, the digital audio signal converted by the analog / digital converter 220 Acoustic characteristic data generation unit 230 convoluting with a reference signal to obtain an impulse response, a filtering unit 240 for filtering the impulse response generated by the acoustic characteristic data generation unit 230, and the filtering unit 240. Determination of the impulse response analysis unit 250 and the impulse response analysis unit 250 to determine whether or not the non-diffusion sound field by analyzing the impulse response for each band generated in And the non-diffusion sound field analysis unit 260 and the impulse response analysis unit 250 which obtain a non-diffusion sound field attenuation rate for the first to third sections of the band-specific impulse response generated by the filtering 240 in the case of a non-diffusion sound field. As a result of the diffused sound field, the diffused sound field analyzer 270, the non-diffused sound field analyzer 260, or the diffused sound field analyzer obtains an attenuation rate of an initial predetermined interval with respect to the band-specific impulse response generated by the filtering unit 240. And an output unit 280 for outputting the result at 270.

The impulse response analyzer 250 determines the non-diffusion sound field when the impulse response for each band is nonlinear, and determines the diffuse sound field when the linear characteristic is used.

The non-diffusion sound field analysis unit 260 is a first section of -5 dB to -15 dB, a second section of -15 dB to -25 dB after sound generation for each band-specific impulse response generated by the filtering unit 240,- For the third section of 25dB to -35dB, the slope of each section is calculated using the slope of each section through regression analysis.

The diffused sound field analyzer 270 obtains an attenuation rate of an initial -5dB to -25dB interval after generating a sound for each band-specific impulse response generated by the filtering unit 240, and multiplies by 3 or an initial -5dB to -35dB interval. Calculate the reverberation time by multiplying 2 by the decay rate of.

3 is a flowchart illustrating a sound measuring method of an indoor space according to the present invention.

Referring to FIG. 3, when an audio signal generated through a speaker is input (S300), the acoustic measurement system converts an analog audio signal into a digital audio signal (S302). The digital audio signal may have a form as shown in FIG. 5.

After performing S302, the acoustic measurement system convolves the digital audio signal with a reference audio signal to obtain an impulse response as shown in FIG. 6 (S304). The impulse response has time and magnitude.

After performing the step S304, the acoustic measurement system filters the obtained impulse response for each band (S306) and generates an impulse response for each band (S308). That is, the acoustic measurement system generates an impulse response for each band by performing filtering on each of the 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 KHz, 2 KHz, 4 KHz, and full bands.

The generated impulse response is in the form as shown in FIG. 7, and a total of eight impulse responses generated by filtering may be provided.

After performing S308, the acoustic measurement system obtains a non-diffusion sound field attenuation rate using regression analysis for the first to third sections of band-specific impulse responses and outputs the results (S310 and S312).

That is, the sound measurement system has a first section T1 of -5 dB to -15 dB, a second section T2 of -15 dB to -25 dB, and -25 dB to -35 dB after the sound is generated for each band impulse response. For each third section of T3, the rate of attenuation is calculated. The first section refers to a section in which the sound level drops by 5 dB to 15 dB after sound generation, the second section refers to a section in which the sound level falls by 5 dB to 25 dB, and the third section refers to a section in which the sound level falls by 25 dB to 35 dB.

The TN (T1, T2, T3) obtained as described above may be used to quantify the degree of acoustic non-diffusion of a space. In other words, if the attenuation ratios of these three sections are similar, they can be interpreted as showing the behavior close to the diffused sound field, and if they differ significantly, the acoustic non-diffusion of the space is very large.

4 is a flowchart illustrating a sound measurement method of an indoor space according to another embodiment of the present invention.

Referring to FIG. 4, when an audio signal generated through a speaker is input (S400), the acoustic measurement system converts the analog audio signal into a digital audio signal (S402).

After performing S402, the acoustic measurement system convolves the digital audio signal with a reference audio signal to obtain an impulse response (S404).

After performing S404, the acoustic measurement system filters the obtained impulse response by band (S406) to generate an impulse response by band (S408). That is, the acoustic measurement system generates an impulse response for each band by performing filtering on each of the 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 KHz, 2 KHz, 4 KHz, and full bands.

The generated impulse response is in the form as shown in FIG. 7, and a total of eight impulse responses generated by filtering may be provided.

Then, the acoustic measurement system analyzes the characteristics of each generated impulse response to determine whether or not the non-diffusion sound field (S410). That is, the acoustic measurement system analyzes the characteristics of each impulse response to determine whether it has nonlinear characteristics. As a result of the determination, if it has a nonlinear characteristic, it is determined as a non-diffusion sound field, and if it has a linear characteristic, it is determined as a diffused sound field.

When the determination result of S410 is a non-diffusion sound field, the acoustic measurement system obtains the non-diffusion sound field attenuation rate using regression analysis for the first to third sections of the band-specific impulse response (S412, S414). That is, the sound measurement system has a first section T1 of -5 dB to -15 dB, a second section T2 of -15 dB to -25 dB, and -25 dB to -35 dB after the sound is generated for each band impulse response. For each third section of T3, the rate of attenuation is calculated.

If the result of the determination in S410 is a diffused sound field, the acoustic measurement system obtains an attenuation rate of an initial -5dB to -25dB interval after the sound is generated for each impulse response for each band, and multiplies by three or an initial -5dB to -35dB interval. The reverberation time is obtained by multiplying the attenuation rate by two (S416) and performing S414.

The attenuation rate index of the non-diffused sound field obtained as described above may be utilized in various fields of an indoor acoustic environment.

First, it is possible to measure and display a sound decay rate similar to the reverberation time even in a non-diffusion space where the reverberation time cannot be measured. By analyzing how much T1, T2, and T3 are and how they tend to change, we determine the overall rate of attenuation of the non-diffusion sound field.

Rather than obtaining a single decay rate (reverberation time) for the entire section by regression on a nonlinear decay curve, add the ⓐ TNs of the different decay rates to -5 dB to -35 dB Particular attention is given to ⓑ T3, which displays or tends to be most similar to subsequent sections (-35 dB to -65 dB), and displays the attenuation rate with [T1 + T2 + (4xT3)], and ⓒT1 → T2 → T3. It is possible to adopt a quantification method that includes a predicted amount for the subsequent period (-35dB to -65dB) after T3 by generalizing the change trend of.

Second, TN can be used to quantify the degree of acoustic non-diffusion in a space. When the attenuation rates of these three sections are similar, it can be interpreted as showing the behavior close to the diffused sound field. If the T1, T2, and T3 are significantly different, the acoustic non-diffusion of the space is very large. In other words, the degree of non-diffusion of the space can be displayed according to the difference between the three attenuation rates.

Third, T1 has a relatively early sound attenuation rate compared to T2 or T3, and thus has a great influence on the degree of masking of subsequent sounds such as sentences and words. Therefore, a new acoustic index indicating the speech intelligibility of the non-diffused sound field can be proposed by placing the weights in order of T1, T2, and T3.

Finally, the trends of T1, T2, and T3 can provide indicators for predicting indoor acoustics. For example, if a relatively long T2 or T3 is measured after a short T1, this means that there is an open surface near the sound source. If T3 is not measured or is measured abnormally long, the space is in a very noisy environment (meaning a high background noise level). If it gets longer to T1, T2, T3, the space is more likely to be acoustically coupled.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

1 and 2 is a block diagram schematically showing the configuration of the acoustic measurement system of the indoor space according to the present invention.

 3 and 4 is a flow chart showing a sound measurement method of the indoor space according to the present invention.

5 is an exemplary view showing an audio signal in a digital form converted by an analog / digital converter according to the present invention.

6 is an exemplary diagram of a frequency response generated by the acoustic characteristic data generating unit according to the present invention.

7 is an exemplary diagram of a frequency response generated by the filtering unit according to the present invention.

<Explanation of symbols for main parts of the drawings>

100, 200: microphone 110, 210: microphone amplifier

120, 220: ADC 130, 230: acoustic characteristic data generation unit

140, 240: filtering unit 150, 260: non-diffusing sound field analysis unit

160, 280: output unit 250: impulse response analysis unit

270: diffuse sound field analysis unit

Claims (16)

An acoustic characteristic data generation unit configured to obtain an impulse response by convolving an audio signal input from the microphone with a reference signal; A filtering unit generating an impulse response for each band by filtering the impulse response generated by the acoustic characteristic data generator for each band; A non-diffusing sound field analysis unit that obtains a sound attenuation rate of each section using regression analysis for the first to third sections of the band-specific impulse response generated by the filtering unit; and  An output unit for outputting a result from the non-diffusion sound field analyzer; Indoor acoustic measurement system comprising a. The method of claim 1, A microphone which is generated by an audio signal generator and receives an audio signal output through a speaker; A microphone amplifier for amplifying the audio signal input from the microphone; and And an analog / digital converting unit converting the analog signal amplified by the microphone amplifying unit into a digital signal and providing the digital signal to the acoustic characteristic data generating unit. The method of claim 1, And the reference signal is an original audio signal generated by an audio signal generator. The method of claim 1, The filtering unit is an indoor acoustic measurement system, characterized in that the octave bandpass filter. The method of claim 1, The filtering unit generates an impulse response for each band by performing filtering on the 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 KHz, 2 KHz, 4 KHz, and full bands of the impulse response generated by the acoustic characteristic data generator. Room acoustic measurement system. The method of claim 1, The non-diffusion sound field analysis unit calculates attenuation rates for the first section in which the sound level falls by 5 dB to 15 dB, the second section in which 15 dB to 25 dB falls, and the third section in which 25 dB to 35 dB falls after the sound is generated for the impulse response for each band. Room acoustic measurement system. 6. The method according to claim 1 or 5, The attenuation rate is calculated by using the slope in each section through the regression analysis. An acoustic characteristic data generation unit configured to obtain an impulse response by convolving an audio signal input from the microphone with a reference signal; A filtering unit generating an impulse response for each band by filtering the impulse response generated by the acoustic characteristic data generator for each band; An impulse response analyzer for determining whether a non-diffusion sound field is analyzed by analyzing the impulse response for each band generated by the filtering unit; A non-diffused sound field analysis unit that obtains a sound decay rate of each section by using a regression analysis on the first to third sections of the band-specific impulse response generated by the filtering unit when the determination result of the impulse response analyzer is determined; A diffused sound field analysis unit for obtaining a sound attenuation rate of an initial predetermined section with respect to the impulse response for each band generated by the filtering unit when the determination result of the impulse response analyzer is determined; and An output unit for outputting a result from the non-diffused sound field analyzer or diffused sound field analyzer; Indoor acoustic measurement system comprising a. The method of claim 8, The impulse response analyzer determines the non-diffusion sound field when the impulse response for each band is nonlinear, and determines the diffuse sound field when it is the linear characteristic. The method of claim 8, The non-diffusion sound field analysis unit calculates attenuation rates for the first section in which the sound level falls by 5 dB to 15 dB, the second section in which 15 dB to 25 dB falls, and the third section in which 25 dB to 35 dB falls after the sound is generated for the impulse response for each band. Room acoustic measurement system. The method of claim 8, The diffused sound field analysis unit obtains the attenuation rate of the section where the sound level falls 5dB ~ 25dB after the sound is generated for each band impulse response, and multiplies by 3 or the result of the decay rate of the section where the sound level falls 5dB ~ 35dB Indoor acoustic measurement system, characterized in that to obtain a. The method of claim 8, A microphone amplifier configured to amplify the audio signal input from the microphone; And an analog / digital converting unit converting the analog signal amplified by the microphone amplifying unit into a digital signal and providing the digital signal to the acoustic characteristic data generating unit. (a) convolving an audio signal input from the microphone with a reference signal to obtain an impulse response; (b) generating an impulse response for each band by filtering the obtained impulse response for each band; (c) analyzing the generated impulse response for each band to determine whether it is a non-diffused sound field; and (d) in the case of the non-diffusion sound field as a result of the determination of step (c), obtaining a decay rate using regression analysis for the first to third sections of the band-specific impulse response; Room acoustic measurement method comprising a. The method of claim 13, The audio signal input from the microphone includes an original audio signal generated through a speaker and a direct sound, an early reflection sound, and a reverberation sound due to spatial characteristics. The method of claim 13, In the case of the diffusion sound field as a result of the determination in step (c), the sound attenuation rate of the sound level drops 5dB to 25dB after the sound is generated for each impulse response for each band, and multiplied by 3 or the sound of the sound level dropped from 5dB to 35dB. Room acoustic measurement method characterized in that the reverberation time is obtained by multiplying the attenuation rate by two. The method of claim 13, In the step (d), after the sound is generated for the impulse response for each band, the sound attenuation rate is respectively set for the first section in which the sound level falls by 5 dB to 15 dB, the second section in which 15 dB to 25 dB falls, and the third section in which 25 dB to 35 dB falls, respectively. The room acoustic measurement method characterized by the above-mentioned.

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