JP2008177795A - Noise output device, noise output method, and noise output program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide "a noise output device, a noise output method, and a noise output program" for obtaining a value of desired coherence characteristics. <P>SOLUTION: The noise output device has a monaural noise output part 101 for outputting monaural noise that the value of coherence characteristics becomes one, an uncorrelated noise output part 102 for outputting uncorrelated noise that the value of coherence characteristics becomes zero, and a noise mixing part 103a that mixes the monaural noise with the uncorrelated noise by combining a prescribed number of monaural noise with a prescribed number of uncorrelated noise in the prescribed order. The device is further provided with a high-pass filter 104, which passes mixed noise in a prescribed frequency band with respect to the mixed noise; an independence maintaining part 105, which cuts out and imparts several tens of seconds in the pre-stage of the passed mixed-noise to the post-stage so as to allow a Right-channel and a Left channel to maintain independence; and a low-pass filter 106 for passing monaural noise in a prescribed frequency band. The noise mixing part 103b mixes the passed mixed-noise with the passed monaural-noise. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a noise output device, and more particularly to a noise output device used when adjusting acoustic characteristics.

  For adjusting the acoustic characteristics in the stereo sound field, for example, the pink noise of the L (Left) channel and the R (Right) channel generated by the noise output device is output from the speaker, and the pink noise is collected by the microphone. It is known that the measurement is performed based on a measurement result obtained by measuring the transfer function.

In Patent Document 1, white noise is generated using a test signal generation source serving as a noise output device, and the white noise output from a speaker is collected by a microphone and measured.
JP 2003-61199 A

  By the way, in the adjustment of the stereo sound field as described above, the theoretical audibility based on the measurement result may be different from the actual audibility. This is caused by the degree of relation (hereinafter referred to as coherence characteristics) generated when the pink noise of the L channel and the pink noise of the R channel are related to each other when the pink noise or the like is measured. Therefore, in order to adjust the stereo sound field corresponding to the actual hearing, it is desirable to generate noise in consideration of the coherence characteristics.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a noise output device, a noise output method, and a noise output program that obtain a desired value of coherence characteristics.

The first aspect of the invention described in claim 1 is a first output means for outputting a first noise having a coherence characteristic value of 1, and a second output means for outputting a second noise having a coherence characteristic value of 0. And a mixing means for combining and mixing a predetermined number of the first noise and the second noise in a predetermined order.
According to this configuration, a noise output device having a desired coherence characteristic can be realized by combining a predetermined number of the first noise and the second noise in a predetermined order.

According to a second aspect of the present invention, in the first aspect of the present invention, the mixed noise of the predetermined frequency band is passed through the mixed noise obtained by mixing the first noise and the second noise. Passing means, independence holding means for cutting out the first tens of seconds of the mixed noise after passing so as to maintain independence and applying it to the subsequent stage, and second passing means for passing the first noise in a predetermined frequency band And the mixing means mixes the mixed noise after the passage and the first noise after the passage.
According to this configuration, a noise output device having coherence characteristics closer to hearing can be realized.

Further, in the invention described in claim 3, in the invention described in claim 1 or 2, the second output means separates one of the channels of the first noise and performs time reversal. The noise is generated.
According to this configuration, if there is the first output means, it is possible to realize a noise output device in which the coherence characteristic has a desired value.

According to a fourth aspect of the present invention, the first noise having a coherence characteristic value of 1 is output, the second noise having a coherence characteristic value of 0 is output, and the first noise and the second noise are output. A noise output method characterized in that a predetermined number of noises are combined and mixed in a predetermined order.
According to this configuration, a noise output device having a desired coherence characteristic can be realized by combining a predetermined number of the first noise and the second noise in a predetermined order.

According to a fifth aspect of the present invention, the computer outputs a first output means for outputting a first noise having a coherence characteristic value of 1, and a second noise having a coherence characteristic value of 0. A noise output program that functions as a second output unit and a mixing unit that combines and mixes a predetermined number of first noise and second noise in a predetermined order.
According to this configuration, a noise output device having a desired coherence characteristic can be realized by combining a predetermined number of the first noise and the second noise in a predetermined order.

  According to the present invention, a desired coherence characteristic value can be obtained, and a difference between a theoretical acoustic characteristic and an auditory acoustic characteristic in a stereo sound field is suppressed.

(First embodiment)
Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a functional block diagram showing a main configuration of a coherence characteristic measuring apparatus including the noise output apparatus 100 according to the first embodiment of the present invention, FIG. 2 is a graph showing the coherence characteristic of monaural noise, and FIG. 3 is an uncorrelated noise. FIG. 4 is a graph showing the coherence characteristics of mixed noise.

  Each functional block shown in FIG. 1 includes a processing device such as a DSP (Digital Signal Processor) and a CPU (Central Processing Unit), a DRAM (Dynamic Random Access Memory), an SRAM (Static RAM), a ROM (Read Only Memory), and the like. The function of each device is realized by the CPU or DSP reading a program stored in the ROM and performing calculations according to the program by the CPU. The same applies to functional blocks described later.

  As shown in FIG. 1, the coherence characteristic measuring apparatus includes a noise output device 100, an amplifying device 110, a measuring device 120, and the like. The noise output device 100 includes a monaural noise output unit 101, an uncorrelated noise output unit 102, a noise mixing unit 103a, and the like.

  The monaural noise output unit 101 is an example of the first output means of the present invention. As shown in FIG. 2, the monaural noise output unit 101 outputs monaural pink noise having a coherence characteristic value of 1 as a result of output from the L channel and the R channel. Output. White noise may be used instead of pink noise. Here, white noise refers to noise in which the intensity of the component included in the unit frequency band (1 kHz) is constant regardless of frequency, and pink noise refers to white noise that has been passed through a low-pass filter of −3 dB / oct. Say. Pink noise has uniform energy over the entire frequency band, and falls slightly to the right on the frequency characteristic graph. Mono pink noise is generated by, for example, a PC (Personal Computer) or the like. Hereinafter, mono pink noise is simply referred to as monaural noise.

  The uncorrelated noise output unit 102 is an example of the second output means of the present invention, and outputs pink noise with a coherence characteristic value of 0 as a result of output from the L channel and the R channel as shown in FIG. To do. The pink noise may be generated from the monaural noise described above. In that case, for example, it is generated by separating any one channel of monaural noise and performing time inversion. For example, if the R channel of monaural noise is separated and time-reversed, and the L channel is left as it is and both are output from the uncorrelated noise output unit 102, the value of the coherence characteristic becomes zero. Hereinafter, pink noise having such characteristics is simply referred to as uncorrelated noise.

  The noise mixing unit 103a is an example of the mixing unit of the present invention, and is configured by one or a plurality. The noise mixing unit 103a combines and mixes a predetermined number of monaural noise and uncorrelated noise in a predetermined order. As described above, desired coherence characteristics can be obtained with respect to monaural noise and uncorrelated noise depending on the number and order of combination. In combination, the L channel and the R channel are mixed in correspondence. Hereinafter, the mixed monaural noise and uncorrelated noise are simply referred to as mixed noise. The mixed noise is transmitted to the amplification device 110.

  The amplifying device 110 converts a digital signal into an analog signal and amplifies the analog signal. In the present embodiment, a pre-main amplifier (INTEGRATED AMPLIFIER) manufactured by LUXMAN and a product name LV-113 are used. The amplified analog signal is transmitted to the measurement device 120. Therefore, the mixed noise as the received digital signal is converted into the mixed noise of the analog signal and amplified, and then transmitted to the measuring device 120. The amplification device 110 can also be realized by other known techniques.

  The measurement apparatus 120 measures the coherence characteristic of the noise output apparatus 100 using FFT (Fast Fourier Transform) with respect to the received mixed noise. In this embodiment, an FFT analyzer manufactured by Ono Sokki Co., Ltd., product name DS-2000 series is used. The measurement is performed by, for example, collecting and measuring mixed noise six times every 20 seconds, and calculating the average value after the measurement. As a result, the value of the coherence characteristic between the L channel and the R channel of mixed noise is about 0.5 as shown in FIG.

Further, the coherence characteristics according to the number of combinations and the combination order of monaural noise and uncorrelated noise will be described with reference to FIGS.
FIG. 5 is another functional block diagram showing the main configuration of the coherence characteristic measuring apparatus, and FIG. 6 is another graph showing the coherence characteristic of the mixed noise. In addition, the same code | symbol is attached | subjected to the structure similar to each part of the coherence characteristic measuring apparatus shown by FIG. 1, and the description is abbreviate | omitted. The same applies to the coherence characteristic measuring apparatus described later.

  As illustrated in FIG. 5, the noise mixing unit 103 b further mixes the monaural noise output from the monaural noise output unit 101 with the mixed noise output from the noise mixing unit 103 a. Therefore, in this aspect, two monaural noises and one uncorrelated noise are mixed in the order of monaural noise, uncorrelated noise, and monaural noise. As a result, the measurement result finally obtained as the coherence characteristic is about 0.85 as shown in FIG.

FIG. 7 is another functional block diagram showing the main configuration of the coherence characteristic measuring apparatus, and FIG. 8 is another graph showing the coherence characteristic of mixed noise.
As illustrated in FIG. 7, the noise mixing unit 103 b further mixes the uncorrelated noise output from the uncorrelated noise output unit 102 with the mixed noise output from the noise mixing unit 103 a. Therefore, in this aspect, one monaural noise and two uncorrelated noises are mixed in the order of monaural noise, uncorrelated noise, and uncorrelated noise. As a result, the measurement result finally obtained as the coherence characteristic is about 0.15 as shown in FIG.

FIG. 9 is another functional block diagram showing the main configuration of the coherence characteristic measuring apparatus, and FIG. 10 is another graph showing the coherence characteristic of mixed noise.
As shown in FIG. 9, the noise mixing unit 103c further mixes uncorrelated noise with the mixed noise output from the noise mixing unit 103b. That is, the noise output device 100 according to this aspect is a mode in which a noise mixing unit 103c is added to the noise output device 100 illustrated in FIG. Therefore, in this aspect, two monaural noises and two uncorrelated noises are mixed in the order of monaural noise, uncorrelated noise, monaural noise, and uncorrelated noise. As a result, the measurement result finally obtained as the coherence characteristic is about 0.3 as shown in FIG.

FIG. 11 is another functional block diagram showing the main configuration of the coherence characteristic measuring apparatus, and FIG. 12 is another graph showing the coherence characteristic of mixed noise.
As illustrated in FIG. 11, the noise mixing unit 103c further mixes uncorrelated noise with the mixed noise output from the noise mixing unit 103b. That is, the noise output device 100 according to this aspect is a mode in which a noise mixing unit 103c is added to the noise output device 100 shown in FIG. Therefore, in this aspect, two monaural noises and two uncorrelated noises are mixed in the order of monaural noise, uncorrelated noise, uncorrelated noise, and monaural noise. As a result, the measurement result finally obtained as the coherence characteristic is about 0.7 as shown in FIG. In this way, noise having various coherence characteristics can be obtained by combining a predetermined number of monaural noise and uncorrelated noise in a predetermined order.

  Further, referring to the drawings, the acoustic characteristics of the stereo sound field when the mixed noise described above is output by an audio device equipped with Adaptive Surround (registered trademark) technology (hereinafter referred to simply as AST) will be referred to. I will explain. AST is a technique for generating 5.1ch surround sound from a stereo source.

  FIG. 13 is a functional block diagram schematically showing how the stereo sound field 200 is adjusted. As shown in FIG. 13, the acoustic characteristics in the stereo sound field 200 are adjusted by forming a speaker 130 in the amplification device 110 instead of the measurement device 120. Therefore, the speaker 130 outputs the amplified mixed noise to the stereo sound field 200. Note that an audio device equipped with an AST may be configured by the noise output device 100, the amplification device 110, and the like. The mixed noise is collected by the microphone 140a of the acoustic characteristic measuring device 140 installed in the stereo sound field 200. In the present embodiment, microphones 140a are provided on both ears of a dummy head (mannequin head), and measurement is performed by 1/12 octave analysis. As a result, in addition to the sound that directly enters the ear, the sound that can be heard through the human shoulder, chest, forehead, etc., the sound that wraps around from the back of the head, that is, all directions Sound and vibration can be collected. The acoustic characteristic measurement device 140 displays a measurement result based on the sound collection result of the mixed noise. Therefore, an operator who adjusts the acoustic characteristics adjusts the acoustic characteristics of the stereo sound field 200 such as the passenger compartment based on the displayed measurement result.

Here, the measurement result of the acoustic characteristic measuring apparatus 140 according to the present embodiment will be described with reference to FIGS. 14 and 15.
FIG. 14 shows the measurement of the acoustic characteristic measuring apparatus 140 that collects mixed pink noise with a coherence characteristic value of about 0.5 in a front car seat with a dummy head microphone installed in front and rear speakers. A graph showing the results, FIG. 15 is a comparative example, and as in FIG. 14, a dummy head microphone is installed in the front seat of the vehicle in an actual vehicle with front and rear speakers mounted thereon, and the value of the coherence characteristic is about 1 or so. It is a graph which shows the measurement result of the acoustic characteristic measuring apparatus 140 which collected monaural pink noise.

  The upper graph shows a graph of the sound pressure average of the left and right ears of the dummy head, and the lower graph shows the difference in sound pressure between the left and right ears of the dummy head. 14 and 15, graphs a and d show the measurement results of the entire stereo sound field 200 (shown as ALL in the figure), and graphs b and e show only the front speakers in the stereo sound field 200. The graphs c and f represent the measurement results when only the rear speaker of the stereo sound field 200 was sounded (represented as Rear in the diagram). . The same applies to graphs described later.

  As shown in the graphs a to c in FIG. 14, the acoustic characteristics according to the present embodiment can be measured sufficiently even when the entire stereo sound field 200, only the front speakers, and only the rear speakers are sounded. In addition, as shown in the graphs d to f in FIG. 14, the sound pressure difference is not greatly shaken as less than 10 dB, and it can be seen that the sense of discomfort is small. On the other hand, as shown in graphs a to c in FIG. 15, the acoustic characteristics according to the comparative example can be measured sufficiently when the entire stereo sound field 200 and only the front speaker are sounded, but only the rear speaker is used. It turns out that a sufficient measurement result cannot be obtained when it rings. As for the sound pressure difference, as shown in the graphs d to f in FIG. 15, a large shake exceeding 10 dB is measured, resulting in a sense of discomfort in the sense of hearing.

  FIG. 16 is a flowchart illustrating an example of noise output processing in the noise output device. The noise output device 100 first outputs monaural noise (step S1), and then outputs uncorrelated noise (step S2). Next, the noise output device 100 mixes monaural noise and uncorrelated noise according to the number of combinations and the combination order (step S3), and ends the noise output processing. As a result, mixed noise having desired coherence characteristics can be obtained.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIGS. 17 to 32 are graphs showing coherence characteristics obtained for 16 arbitrarily selected pieces of music. More specifically, it is a graph of coherence characteristics obtained by measuring 2 minutes from the start of the performance of each song divided into 6 times every 20 seconds and averaging the measurement results.

  As shown in FIGS. 17 to 32, the coherence characteristics have various tendencies depending on the music. Here, when a simple average is calculated for these coherence characteristics, as shown in FIG. 33, for a band of 100 Hz or less, the value of the coherence characteristics is approximately 1 and gradually decreases from 100 Hz to 250 Hz, and is 250 Hz or more. In this band, the value of the coherence characteristic is converged to about 0.5. Therefore, by providing the noise output device 100 having such a coherence characteristic as a measurement result, the difference between the theoretical audibility based on the measurement result and the actual audibility is reduced.

  FIG. 34 is a functional block diagram showing the main configuration of the coherence characteristic measuring apparatus according to the second embodiment. As shown in FIG. 34, the coherence characteristic measuring device includes a noise output device 100, an amplifying device 110, a measuring device 120, and the like. The noise output device 100 includes a monaural noise output unit 101, an uncorrelated noise output unit 102, noise mixing units 103a and 103b, a high-pass filter 104, an independence holding unit 105, a low-pass filter 106, and the like.

  The high-pass filter 104 is an example of the first passing means of the present invention, and cuts the low frequency of the input mixed noise and selectively passes the high frequency. The low-pass filter 106 is an example of the second passing means of the present invention, and cuts the high frequency of the input monaural noise and selectively passes the low frequency. These levels can be determined according to the design. In this embodiment, both use the 200 Hz band, but the present invention is not limited to this.

  The independence holding unit 105 is an example of the independence holding unit according to the present invention. The independence holding unit 105 reduces the previous stage of the mixed noise after passing through the high-pass filter 104 so that the independence of both channels is maintained (discrete). Cut out and add to the subsequent stage. The cutout is preferably about 30 seconds. As a result, the power spectrum (frequency characteristic) of the noise obtained by synthesizing the monaural noise after passing through the low-pass filter 106 and the mixed noise after passing through the high-pass filter 104 so that it substantially matches the power spectrum of the monaural noise. Become. The power spectrum matching will be described in more detail below.

Next, measurement results and the like of the coherence characteristic measuring apparatus according to the second embodiment will be described with reference to FIGS.
35 is a graph showing the coherence characteristic of the mixed noise after passing through the high-pass filter 104, FIG. 36 is a graph showing the power spectrum of the L channel of the mixed noise after passing through the high-pass filter 104, and FIG. 37 is a graph of the mixed noise after passing through the high-pass filter. 38 is a graph showing the power spectrum of the R channel, FIG. 38 is a graph showing the coherence characteristic of monaural noise after passing through the low-pass filter 106, FIG. 39 is a graph showing the power spectrum of the L channel of mixed noise after passing through the low-pass filter, and FIG. FIG. 41 is a graph showing the power spectrum of the R channel of the mixed noise after passing through the low-pass filter. FIG. 41 is a graph showing the power spectrum of the mixed noise after passing through the high-pass filter and the power spectrum of the mixed noise after passing through the low-pass filter. The graph of the coherence properties of the mixed noise output from the noise output device 100 according to the embodiment, FIG. 43 is a graph showing the power spectrum of the composite waveform, FIG. 44 is a graph showing the power spectrum of the mono noise.

  The monaural noise output from the monaural noise output unit 101 and the uncorrelated noise output from the uncorrelated noise output unit 102 are mixed by the noise mixing unit 103a and become mixed noise. The coherence characteristic of the mixed noise is about 0.5 as shown in FIG. 4 described above.

  The high pass filter 104 cuts low frequencies and selectively passes high frequencies with respect to the mixed noise. Thereby, it can be seen that the coherence characteristic of the mixed noise after passing through the high-pass filter 104 converges to about 0.5 as shown in FIG. Further, the power spectrum of the L channel of the mixed noise after passing through the high pass filter 104 is a peak-shaped graph as shown in FIG. 36, and the power spectrum of the R channel of the mixed noise after passing through the high pass filter 104 is also As shown in FIG. 37, it is a peak-shaped graph.

  On the other hand, the coherence characteristic of monaural noise output from the monaural noise output unit 101 is about 1 as shown in FIG. The low pass filter 106 cuts the high frequency and selectively passes the low frequency to the monaural noise. As a result, the coherence characteristic of monaural noise after passing through the low-pass filter 106 changes at about 1 until about 2.5 kHz as shown in FIG. 38, but the signal level decreases from 2.5 kHz to 10 kHz. It can be seen that the value of the coherence characteristic decreases and converges to about 0 after 10 kHz. Further, as shown in FIG. 39, the power spectrum of the L channel of monaural noise after passing through the low-pass filter 106 decreases from 25 Hz to 2.5 kHz, and becomes 0 after 2.5 kHz. As shown in FIG. 40, the power spectrum of the R channel of monaural noise also decreases from 25 Hz to 2.5 kHz, and is 0 after 2.5 kHz.

  Furthermore, FIG. 41 shows a graph representing a simple average for the power spectrum of both channels after passing through the high-pass filter and a graph representing a simple average for the power spectrum of both channels after passing through the low-pass filter. In FIG. 41, a graph a indicates the former, and a graph b indicates the latter.

  Here, the independence holding unit 105 performs the independence holding process on the mixed noise after passing through the high-pass filter 104 described above, and further, the noise mixing unit 106 receives the mixed noise and the monaural noise after passing through the low-pass filter 104. Mix. Then, when the coherence characteristic of noise obtained from the mixing result is measured, as shown in FIG. 42, for a band of 100 Hz or less, the value of the coherence characteristic is about 1 and gradually decreases from 100 Hz to 250 Hz. In the above band, the value of the coherence characteristic is approximately 0.5, and the shape is close to the coherence characteristic shown in FIG.

  Further, when a simple average is calculated for both graphs a and b of the power spectrum shown in FIG. 41, as shown in FIG. 43, a graph that descends substantially linearly from 25 Hz to 20 Khz is obtained. On the other hand, when the power spectrum in monaural noise is calculated, as shown in FIG. 44, a graph that is substantially equal to the graph shown in FIG. 43 and descends substantially linearly from 25 Hz to 20 Khz is obtained. As described above, by using the noise output device 100 according to the present embodiment, it is possible to realize the desirable acoustic characteristics of the stereo sound field 100 from the first embodiment while the power spectrum of monaural noise is substantially the same. It becomes. As shown in FIG. 16 described above, it is also possible to generate a program that realizes these functions.

  FIG. 45 is a graph showing a measurement result of the acoustic characteristic measurement device using the noise output device according to the second embodiment. As for the acoustic characteristics according to the comparative example, as shown in the graph of FIG. 15 described above, the measurement result of the sound from the rear speaker in the passenger compartment has not been sufficiently obtained. On the other hand, as shown in the graphs a to c in FIG. 45, the acoustic characteristics according to this embodiment can be measured sufficiently for the entire stereo sound field 200, the front speaker, and the rear speaker. In addition, as shown in the graphs d to f in FIG. 45, the sound pressure difference does not greatly fluctuate less than about 10 dB, and it is understood that there is little sense of discomfort in hearing. In this way, the acoustic characteristics of the stereo sound field 200 such as the passenger compartment can be adjusted by using the high-pass filter 104 or the like. In particular, the evaluation of the surround system such as AST can also obtain an appropriate result.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. The program of the present invention can be provided not only by communication means but also stored in a recording medium such as a CD-ROM.

  As described above, according to the noise output device of the present invention, a desired coherence characteristic value can be obtained, and a difference between a theoretical acoustic characteristic and an audible acoustic characteristic in a stereo sound field is suppressed. Therefore, the industrial applicability is high.

It is a functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 1st Embodiment. It is a graph which shows the coherence characteristic of monaural noise. It is a graph which shows the coherence characteristic of uncorrelated noise. It is a graph which shows the coherence characteristic of mixed noise. It is another functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 1st Embodiment. It is another graph which shows the coherence characteristic of mixed noise. It is another functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 1st Embodiment. It is another graph which shows the coherence characteristic of mixed noise. It is another functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 1st Embodiment. It is another graph which shows the coherence characteristic of mixed noise. It is another functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 1st Embodiment. It is another graph which shows the coherence characteristic of mixed noise. It is a functional block diagram which shows the principal part structure of an acoustic characteristic measuring apparatus. It is a graph which shows the measurement result of the acoustic characteristic measuring device concerning an embodiment. It is a graph which shows the measurement result of the acoustic characteristic measuring device concerning a comparative example. It is a flowchart which shows an example of the noise output process in a noise output device. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the coherence characteristic of a music. It is an example of the graph which shows the average of the coherence characteristic of a music. It is a functional block diagram which shows the principal part structure of the coherence characteristic measuring apparatus which concerns on 2nd Embodiment. It is a graph which shows the coherence characteristic of the mixed noise after passing a high pass filter. It is a graph which shows the power spectrum of the L channel of the mixed noise after passing a high pass filter. It is a graph which shows the power spectrum of R channel of the mixed noise after passing a high pass filter. It is a graph which shows the coherence characteristic of the monaural noise after passing a low-pass filter. It is a graph which shows the power spectrum of the L channel of the mixed noise after passing a low-pass filter. It is a graph which shows the power spectrum of R channel of the mixed noise after passing a low-pass filter. It is a graph which shows the power spectrum of the mixed noise after passing a high pass filter, and the power spectrum of the mixed noise after passing a low pass filter. It is a graph which shows the coherence characteristic of the mixed noise which concerns on embodiment. It is a graph which shows the power spectrum of a synthetic | combination waveform. It is a graph which shows the power spectrum of monaural noise. It is a graph which shows the measurement result of the acoustic characteristic measuring device concerning an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Noise output device 101 Monaural noise output part 102 Uncorrelated noise output part 103a-103c Noise mixing part 104 High pass filter 105 Independence holding part 106 Low pass filter 110 Amplifying apparatus 120 Measuring apparatus 130 Speaker 140 Acoustic characteristic measuring apparatus 200 Stereo sound Place

Claims (5)

First output means for outputting a first noise having a coherence characteristic value of 1,
A second output means for outputting a second noise having a coherence characteristic value of 0;
A mixing means for combining and mixing a predetermined number of the first noise and the second noise in a predetermined order;
A noise output device comprising: First passing means for passing mixed noise of a predetermined frequency band with respect to mixed noise obtained by mixing the first noise and the second noise;
An independence holding means for cutting out several tens of seconds before the mixed noise after passing so as to maintain the independence and giving it to the subsequent stage;
Second passing means for passing the first noise of a predetermined frequency band,
The noise output device according to claim 1, wherein the mixing unit mixes the mixed noise after the passage and the first noise after the passage.   3. The noise according to claim 1, wherein the second output unit generates the second noise by separating one of the channels of the first noise and performing time inversion. 4. Output device. The first noise with a coherence characteristic value of 1 is output,
Outputs second noise with a coherence characteristic value of 0,
A noise output method comprising combining a predetermined number of the first noise and the second noise in a predetermined order and mixing them. Computer
First output means for outputting a first noise having a coherence characteristic value of 1,
A second output means for outputting a second noise having a coherence characteristic value of 0;
A noise output program that functions as a mixing unit that combines and mixes a predetermined number of the first noise and the second noise in a predetermined order.

Images