JP5907488B2 - Reproduction signal generation method, sound collection reproduction method, reproduction signal generation apparatus, sound collection reproduction system, and program thereof - Google Patents

Description

  The present invention relates to a technique for generating a signal to be reproduced in a highly realistic sound reproduction apparatus.

  A sound reproducing device described in Non-Patent Document 1 is known as a highly realistic sound reproducing device. In Non-Patent Document 1, only the impulse response is measured in the model, and the impulse response and non-sounding music (sound pickup signal) are convolved and calculated in post-processing, thereby realizing a highly realistic sound reproduction device. ing.

Oga, Yamazaki, Kaneda, "Acoustic System and Digital Processing", IEICE, 1995, pp. 48-50,245

  However, the conventional technique requires a large amount of calculation when the impulse response is long (the reverberation is long). Alternatively, a mixing engineer is required every time an operation is required, resulting in high costs.

  It is an object of the present invention to provide a reproduction signal generation technique that generates a reproduction signal with a smaller amount of calculation compared to the conventional technique without requiring a mixing engineer.

  In order to solve the above problems, according to a first aspect of the present invention, a reproduction signal generation method includes a sound source arranged in the first original sound field and a speaker arranged in the reproduction sound field, where m is a discrete time. The direct wave component filter An (m) representing the amplitude of the direct wave component of the impulse response observed by the measurement microphone arranged in the first original sound field so as to correspond to δ corresponding to the delay time Dn of the impulse response A storage step for storing a delay time filter δ (m-Dn) representing a function, and a sound pickup signal x obtained from a live microphone arranged in the second original sound field so as to have the same positional relationship as the measurement microphone (m) includes a calculation step of convolving a direct wave component filter An (m) and a delay time filter Δ (m−Dn).

  In order to solve the above-described problem, according to the second aspect of the present invention, a sound collection and reproduction method includes a sound source arranged in the first original sound field and a speaker arranged in the reproduction sound field, where m is a discrete time. The direct wave component filter An (m) representing the amplitude of the direct wave component of the impulse response observed by the measurement microphone arranged in the first original sound field so as to correspond to δ corresponding to the delay time Dn of the impulse response A storage step for storing a delay time filter δ (m-Dn) representing a function and a collected sound signal x (m from an actual microphone arranged in the second original sound field so as to have the same positional relationship as the measurement microphone. ), A calculation step of convolving the direct wave component filter An (m) and the delay time filter δ (m-Dn) with the collected signal x (m), and the convolved signal A playback step of playing back the playback signal.

  In order to solve the above-described problem, according to a third aspect of the present invention, a reproduction signal generation device uses m as a discrete time and a sound source arranged in the first original sound field and a speaker arranged in the reproduction sound field. The direct wave component filter An (m) representing the amplitude of the direct wave component of the impulse response observed by the measurement microphone arranged in the first original sound field so as to correspond to δ corresponding to the delay time Dn of the impulse response The collected sound signal obtained from the storage unit storing the delay time filter δ (m-Dn) representing the function and the live microphone arranged in the second original sound field so as to have the same positional relationship as the measurement microphone Calculation means for convolving a direct wave component filter An (m) and a delay time filter Δ (m−Dn) with respect to x (m) is included.

  In order to solve the above problem, according to a fourth aspect of the present invention, a sound collection and reproduction system includes a sound source arranged in the first original sound field and a speaker arranged in the reproduction sound field, where m is a discrete time. The direct wave component filter An (m) representing the amplitude of the direct wave component of the impulse response observed by the measurement microphone arranged in the first original sound field so as to correspond to δ corresponding to the delay time Dn of the impulse response From the storage unit storing the delay time filter δ (m-Dn) representing the function, the live microphone arranged in the second original sound field so as to have the same positional relationship as the measurement microphone, and the live microphone With respect to the obtained sound pickup signal x (m), arithmetic means for convolving the direct wave component filter An (m) and the delay time filter δ (m-Dn), and a reproduction signal including the convolved signal are reproduced. Including a speaker.

  According to the present invention, there is an effect that it is possible to automatically perform mixing with a small amount of calculation compared to the prior art and generate a reproduction signal without requiring a mixing engineer.

The figure for demonstrating the positional relationship of the sound source and the measurement microphone in the 1st original sound field which concerns on 1st embodiment. The figure for demonstrating the sound collection reproduction | regeneration system which concerns on 1st embodiment. The figure which shows the processing flow of the sound collection reproduction | regeneration system which concerns on 1st embodiment. 1 is a functional block diagram of a reproduction signal generation device according to a first embodiment. The figure for demonstrating the positional relationship of the sound source and measurement microphone in the 1st original sound field which concerns on 2nd embodiment. The figure for demonstrating the sound collection reproduction | regeneration system which concerns on 2nd embodiment. The figure which shows the processing flow of the sound collection reproduction | regeneration system which concerns on 2nd embodiment. The functional block diagram of the reproduction | regeneration signal generation apparatus which concerns on 2nd embodiment. The figure for demonstrating the positional relationship of the sound source and the measurement microphone in the 1st original sound field which concerns on the modification of 2nd embodiment. The figure for demonstrating the sound collection reproduction | regeneration system which concerns on the modification of 2nd embodiment. The figure for demonstrating the positional relationship of the sound source and measurement microphone in the 1st original sound field which concerns on 3rd embodiment. The figure for demonstrating the sound collection reproduction | regeneration system which concerns on 3rd embodiment. The figure which shows the processing flow of the sound collection reproduction | regeneration system which concerns on 3rd embodiment. The functional block diagram of the reproduction | regeneration signal generation apparatus which concerns on 3rd embodiment.

  Hereinafter, embodiments of the present invention will be described. In the drawings used for the following description, constituent parts having the same function and steps for performing the same processing are denoted by the same reference numerals, and redundant description is omitted. Further, the processing performed for each element of a vector or matrix is assumed to be applied to all elements of the vector or matrix unless otherwise specified.

<Points of first embodiment>
In this embodiment, instead of the impulse response, the direct wave component An of the impulse response and the delay time Dn until the direct wave component arrives are used. m is discrete time, δ (m−Dn) is a delay time filter representing a δ function corresponding to the delay time Dn, An (m) is a direct wave component filter representing the amplitude of the direct wave component, and x (m ), The output signal y (m) is expressed by the following equation (1).
y (m) = x (m) * δ (m−Dn) * An (m) (1)
However, * represents a convolution operation. Here, since the filter length of the delay time filter δ (m−Dn) and the direct wave component filter An (m) is much shorter than the filter length of the filter hn (m) representing the impulse response, the collected sound signal x Compared with the direct convolution of (m) and the filter hn (m), the amount of computation is much smaller. For example, if the sampling frequency is 20 kHz and the reverberation time is 200 ms, the filter length of the filter hn (m) usually requires around 4096, whereas the direct wave component filter An (m) has a filter length of 256 to 512. (About 1/16 to 1/8 of the filter length of the filter hn (m)), the filter length of the delay time filter δ (m−Dn) is 256 to 1024 (1/8 to the filter length of the filter hn (m) (About 1/4) is sufficient. However, the filter lengths of the direct wave component filter An (m) and the delay time filter δ (m−Dn) may be appropriately changed according to the reverberation time of the sound field to be simulated, and may be shorter or longer than the above example. . The output signal y (m) is reduced with a small amount of calculation according to the expression (1), rather than at least shorter than the filter length of the filter hn (m) and directly convolving the collected sound signal x (m) and the filter hn (m). So that the filter lengths of the direct wave component filter An (m) and the delay time filter Δ (m−Dn) may be set.

<First embodiment>
In this embodiment, only the impulse response is measured in the first original sound field. The reproduction signal generation apparatus 100 according to the present embodiment performs a direct wave component filter An (m) of an impulse response and a delay time filter δ (m−Dn) with respect to a signal (sound collection signal) collected in the second original sound field. ) To generate a reproduction signal. Details will be described below.

<Pre-processing>
Hereinafter, a method for measuring the impulse response in the first original sound field will be described. FIG. 1 is a diagram for explaining the positional relationship between a sound source and a measurement microphone in the first original sound field.

  (1) First, a virtual sound receiving point 4 (so-called sweet spot) is set in the first original sound field 1.

  (2) From this point, considering the surround arrangement of the 5.1ch surround speakers (see FIG. 2), a virtual line of ± 30 ° is extended in the front, and the stage 5 is moved to a position within this range. Place two sound sources. The two sound sources are called MS_L2-1 and MS_R2-2 in the meaning of Measurement Source_Left and Measurement Source_Right, respectively.

  (3) A position where the surround speaker is arranged in the reproduction sound field 31 to be described later is set (see FIG. 2), and the measurement microphone is placed in the first original sound field 1 so as to correspond to the position around the sound receiving point 4. Deploy. However, measurement microphones are not installed at positions corresponding to the position of the center speaker 32-5 and the position of the subwoofer 32-6, and are omitted. In other words, measurement microphones are respectively installed at the left front, right front, left rear, and right rear so as to surround the sound receiving point 4. The four measurement microphones are referred to as Measurement Microphone_Left-Front, Measurement Microphone_Right-Front, Measurement Microphone_Left-Rear, and Measurement Microphone_Right-Rear, respectively, as MM_LF3-1, MM_RF3-2, MM_LR3-3, and MM_RR3-4. The above-described sound sources MS_L2-1 and MS_R2-2 are outside the area formed by the four measurement microphones MM_LF3-1, MM_RF3-2, MM_LR3-3, and MM_RR3-4, and are respectively left of the sound receiving points. It can be said that they are arranged in front and right front.

(4) Measure impulse responses from the sound sources MS_L2-1 and MS_R2-2 to the measurement microphones MM_LF3-1, MM_RF3-2, MM_LR3-3, and MM_RR3-4. Impulse responses from the sound source MS_L2-1 to the measurement microphones MM_LF3-1, MM_RF3-2, MM_LR3-3, and MM_RR3-4 are expressed as MS_L-MM_LF, MS_L-MM_RF, MS_L-MM_LR, MS_L-MM_RR, and the sound source MS_R2 -2 to the measurement microphones MM_LF3-1, MM_RF3-2, MM_LR3-3, and MM_RR3-4 are denoted as MS_R-MM_LF, MS_R-MM_RF, MS_R-MM_LR, and MS_R-MM_RR, respectively. Then, from the measured impulse responses MS_L-MM_LF, MS_L-MM_RF, MS_L-MM_LR, MS_L-MM_RR, MS_R-MM_LF, MS_R-MM_RF, MS_R-MM_LR, MS_R-MM_RR, the direct wave component filter An _{MS_L- MM_LF} (m), An _{MS_L-MM_RF} (m), An _{MS_L-MM_LR} (m), An _{MS_L-MM_RR} (m), An _{MS_R-MM_LF} (m), An _{MS_R-MM_RF} (m), An _{MS_R-MM_LR} ( m), An _{MS_R-MM_RR} (m) and delay filter δ (m-Dn _{MS_L-MM_LF} ), δ (m-Dn _{MS_L-MM_RF} ), δ (m-Dn _{MS_L-MM_LR} ), δ (m-Dn _{MS_L -MM_RR} ), δ (m-Dn _{MS_R-MM_LF} ), δ (m-Dn _{MS_R-MM_RF} ), δ (m-Dn _{MS_R-MM_LR} ), δ (m-Dn _{MS_R-MM_RR} ) The data is stored in the storage unit 130 in the generation device 100.

<Sound Collection Playback System 200>
FIG. 2 is a diagram for explaining the sound collection / reproduction system 200. FIG. 3 shows a processing flow of the sound collection / reproduction system 200. The sound collection reproduction system 200 is a system that collects sound in the second original sound field 11, transmits a sound collection signal, and reproduces it in the reproduction sound field 31. Note that this system does not perform an operation such as canceling the influence of the reproduction sound field 31, and is assumed to be dead to some extent (poor sound).

<Second original sound field 11>
Two live microphones are installed on the stage 13 of the second original sound field 11 at intervals of about the sound sources MS-L3-1 and MS-R302 of FIG. In the sense of Live Microphone_Left-Front and Live Microphone_Right-Front, they are called LM_LF12-1 and LM_RF12-2. Here, it is assumed that the actual microphones LM_LF12-1 and LM_RF12-2 have a single directivity and can separate the sound on the left and right sides of the stage as much as possible. In addition, an auxiliary live microphone will be installed at the center. It is called LM_C12-5 in the sense of Live Microphone_center.

  Next, live microphones are placed near the left and right wall surfaces for ambient sound collection. In the sense of Live Microphone_Left-Rear and Live Microphone_Right-Rear, they are called LM_LR12-3 and LM_RR12-4.

  By arranging the live microphones LM_LF12-1, LM_RF12-2, LM_LR12-3, and LM_RR12-4 in this way, the positional relationship of the live microphones is the measurement microphone MM_LF3-1 in the first original sound field 1, This is the same as the positional relationship of MM_RF 3-2, MM_LR 3-3, and MM_RR 3-4.

  LM_LF12-1, LM_RF12-2, LM_LR12-3, LM_RR12-4, and LM_C12-5 each collect the sound uttered in the second original sound field 11 (s1) and collect the collected sound signal x_LF (m), x_RF (m), x_LR (m), x_RR (m), and x_C (m) are output to the reproduction signal generation device 100 via the transmission unit 21 and the reception unit 22. In the present embodiment, only the sound collected signals for five channels after the output of the microphone amplifier are used, and no particular mixing is performed on the sound collecting side. The collected sound signals x_LF (m), x_RF (m), x_LR (m), x_RR (m) and x_C (m) are transmitted by, for example, AES / EBU (one of professional digital audio signal transmission standards). . The transmission means 21 and the reception means 22 are connected by an optical fiber or the like.

<Reproduction signal generating apparatus 100>
FIG. 4 shows a functional block diagram of the reproduction signal generation apparatus 100. The reproduction signal generating apparatus 100 includes a storage unit 130, a first calculation unit 111, a second calculation unit 112, a third calculation unit 113, a fourth calculation unit 114, a fifth calculation unit 115, a sixth calculation unit 116, and a seventh calculation unit. The calculation unit 117 and the eighth calculation unit 118, the first addition unit 121, the second addition unit 122, the third addition unit 123, and the fourth addition unit 124 are included.

<Storage unit 130>
As described above, the storage unit 130 stores the direct wave component filter and the delay time filter of each impulse response observed by the sound source arranged in the first original sound field 1 and the measurement microphone (s2).

<Calculation means>
Each arithmetic means takes out the corresponding direct wave component filter and delay time filter of the impulse response from the storage unit 130, respectively, and puts it in the second original sound field 11 so as to have the same positional relationship as the measurement microphone. A direct wave component filter An (m) and a delay time filter Δ (m−Dn) of impulse response are convoluted with the collected sound signal obtained from (S3).

For example, the first calculation means 111 performs an impulse response MS_R-MM_LF on the collected sound signal x_RF (m) obtained from the live microphone LM_RF 12-2 arranged in the same positional relationship as the measurement microphone MM_RF3-2. The direct wave component filter An _{MS_R-MM_LF} (m) and the delay time filter Δ (m-Dn _{MS_R-MM_LF} ) are convoluted by the following equation to obtain the first output signal y _{MS_R-MM_LF} (m).
y _{MS_R-MM_LF} (m) = x_RF (m) * δ (m-Dn _{MS_R-MM_LF} ) * An _{MS_R-MM_LF} (m)

Similarly, the second to fourth calculation means 112 to 114 respectively perform the sound pickup signal x_RF (m) obtained from the live microphone LM_RF 12-2 arranged in the same positional relationship as the measurement microphone MM_RF3-2. , Impulse response MS_R-MM_RF, MS_R-MM_LR, MS_R-MM_RR direct wave component filter An _{MS_R-MM_RF} (m), An _{MS_R-MM_LR} (m), An _{MS_R-MM_RR} (m) and delay time filter δ (m -Dn _{MS_R-MM_RF} ), δ (m-Dn _{MS_R-MM_LR} ), δ (m-Dn _{MS_R-MM_RR} ) are convolved, respectively, and the second output signal y _{MS_R-MM_RF} (m) and the third output signal y _{MS_R- MM_LR} (m) and the fourth output signal y _{MS_R-MM_RR} (m) are obtained.

Similarly, the fifth to eighth arithmetic means 115 to 118 perform the sound collection signal x_LF (m) obtained from the live microphone LM_LF12-1 disposed in the same positional relationship as the measurement microphone MM_LF3-1. , Impulse response MS_L-MM_LF, MS_L-MM_RF, MS_L-MM_LR, MS_L-MM_RR direct wave component filter An _{MS_L-MM_LF} (m), An _{MS_L-MM_RF} (m), An _{MS_L-MM_LR} (m), An _{MS_L -MM_RR} (m) and delay time filters δ (m-Dn _{MS_L-MM_LF} ), δ (m-Dn _{MS_L-MM_RF} ), δ (m-Dn _{MS_L-MM_LR} ), δ (m-Dn _{MS_L-MM_RR} ) Convolution, fifth output signal y _{MS_L-MM_LF} (m), sixth output signal y _{MS_L-MM_RF} (m), seventh output signal y _{MS_L-MM_LR} (m), eighth output signal y _{MS_L-MM_RR} (m) Ask for.

<Adding unit>
The first adder 121 adds the first output signal y _{MS_R-MM_LF} (m) and the fifth output signal y _{MS_L-MM_LF} (m), and outputs the reproduction signal y_LF (m) to the speaker S_LF 32-1 ( s4).
y_LF (m) = y _{MS_R-MM_LF} (m) + y _{MS_L-MM_LF} (m)

The second addition unit 122 adds the second output signal y _{MS_R-MM_RF} (m) and the sixth output signal y _{MS_L-MM_RF} (m), and outputs the reproduction signal y_RF (m) to the speaker S_RF 32-2 ( s5).
y_RF (m) = y _{MS_R-MM_RF} (m) + y _{MS_L-MM_RF} (m)

The third adder 123 adds the third output signal y _{MS_R-MM_LR} (m), the seventh output signal y _{MS_L-MM_LR} (m), and the collected sound signal x_LR (m) obtained from the live microphone LM_LR 12-3. The reproduction signal y_LR (m) is output to the speaker S_LR 32-3 (s6).
y_LR (m) = y _{MS_R-MM_LR} (m) + y _{MS_L-MM_LR} (m) + x_LR (m)

The fourth adder 124 adds the fourth output signal y _{MS_R-MM_RR} (m), the eighth output signal y _{MS_L-MM_RR} (m), and the collected sound signal x_RR (m) obtained from the live microphone LM_RR 12-4. Then, the reproduction signal y_RR (m) is output to the speaker S_RR 32-4 (s7).
y_RR (m) = y _{MS_R-MM_RR} (m) + y _{MS_L-MM_RR} (m) + x_RR (m)

  If the sound collection ranges of the live microphones LM_LF12-1 and LM_RF12-2 are not sufficiently separated, sounds that overlap more than necessary are reproduced twice. For example, the reproduction signal generating apparatus 100 can be realized by a DAW (Digital Audio Workstation) and plug-in software.

<Playback sound field 31>
The reproduction sound field 31 includes a center speaker S_C3-5, a front speaker S_LF32-1, an S_RF32-2, and a rear speaker S_LR32- in front, left front, right front, left rear, and right rear so as to surround the sound receiving point. 3, S_RR32-4 is arranged. Further, a subwoofer 32-6 is arranged in the vicinity of the center speaker S_C32-5.

  The center speaker S_C32-5 reproduces the sound pickup signal x_C (m) from the live microphone LM_C12-5 after adjusting the level appropriately. The subwoofer 32-6 reproduces the very low frequency range (approximately 20 Hz to 100 Hz) of the collected sound signal x_C (m).

  The front speakers S_LF32-1, S_RF32-2, rear speakers S_LR32-3 and S_RR32-4 reproduce the input reproduction signals y_LF (m), y_RF (m), y_LR (m) and y_RR (m), respectively ( s8).

<Effect>
With this configuration, the volume of each channel can be set without requiring a mixing engineer. In addition, since the impulse response itself is not used but only the direct wave component and the delay time are used, the sound field can be easily adjusted with a small amount of calculation compared to the case where the impulse response is convoluted.

<Modification>
When the center speaker S_C32-5, the front speakers S_LF32-1, S_RF32-2, the rear speakers S_LR32-3 and S_RR32-4 have sufficient bass reproduction capability, the sound collection and reproduction system 200 can be connected to the subwoofer 32- 6 may not be included. Further, when the front speakers S_LF 32-1 and S_RF 32-2 have sufficient reproduction capability, the center speaker S_C 32-5 may not be included.

In the first embodiment, simple sound field adjustment is possible without adding ambient sound. In this case, the live microphones LM_LR12-3 and LM_RR12-4 need not be provided. The third adder 123 adds the third output signal y _{MS_R-MM_LR} (m) and the seventh output signal y _{MS_L-MM_LR} (m), and outputs the reproduction signal y_LR (m) to the speaker S_LR 32-3. To do.
y_LR (m) = y _{MS_R-MM_LR} (m) + y _{MS_L-MM_LR} (m)

The fourth adder 124 adds the fourth output signal y _{MS_R-MM_RR} (m) and the eighth output signal y _{MS_L-MM_RR} (m), and outputs the reproduction signal y_RR (m) to the speaker S_RR 32-4. To do.
y_RR (m) = y _{MS_R-MM_RR} (m) + y _{MS_L-MM_RR} (m) + x_RR (m)

  In the present embodiment, the reproduction signal generation device 100 is installed on the reception side. However, the reproduction signal generation apparatus 100 may be installed on the transmission side to transmit the generated reproduction signal. Moreover, you may install as a server on a network.

  In the present embodiment, the first original sound field and the second original sound field are different sound fields, but the same sound field may be used.

<Second embodiment>
Only parts different from the first embodiment will be described.

<Pre-processing>
Hereinafter, a method for measuring the impulse response in the first original sound field will be described. FIG. 5 is a diagram for explaining the positional relationship between the sound source and the measurement microphone in the first original sound field.

  (1) First, a virtual sound receiving point 4 (so-called sweet spot) is set in the first original sound field 1.

  (2) From the sound receiving point 4 in consideration of the arrangement of the stereo speakers (see FIG. 6), a virtual line of ± 30 ° is extended forward, and two sound sources are located on the stage 5 within the range. MS_L2-1 and MS_R2-2 are arranged. The sound sources MS_L2-1 and MS_R2-2 are arranged on the left and right sides of the sound receiving point 4, respectively.

  (3) A position where a stereo speaker is arranged in a reproduction sound field 31 to be described later is set (see FIG. 6), and measurement microphones MM_L3-1 and MM_R3-2 are arranged on the left and right sides of the sound receiving point 4, respectively.

(4) Measure impulse responses from the sound sources MS_L2-1 and MS_R2-2 to the measurement microphones MM_L3-1 and MM_R3-2. Impulse responses from the sound source MS_L2-1 to the measurement microphones MM_L3-1 and MM_R3-2 are denoted as MS_L-MM_L and MS_L-MM_R, respectively, and impulses from the sound source MS_R2-2 to the measurement microphones MM_L3-1 and MM_R3-2 Responses are expressed as MS_R-MM_L and MS_R-MM_R, respectively. Then, from the measured impulse responses MS_L-MM_L, MS_L-MM_R, MS_R-MM_L, MS_R-MM_R, the direct wave component filters An _{MS_L-MM_L} (m), An _{MS_L-MM_R} (m), An _{MS_R- MM_L} (m), An _{MS_R-MM_R} (m) and delay filter δ (m-Dn _{MS_L-MM_L} ), δ (m-Dn _{MS_L-MM_R} ), δ (m-Dn _{MS_R-MM_L} ), δ (m- Dn _{MS_R-MM_R} ) is generated and stored in the storage unit 130 in the reproduction signal generation apparatus 100.

<Sound Collection Playback System 200>
FIG. 6 is a diagram for explaining the sound collection / reproduction system 200. FIG. 7 shows a processing flow of the sound collection / reproduction system 200.

<Second original sound field 11>
Two live microphones LM_L12-1 and LM_R12-2 are installed on the stage 13 of the second original sound field 11 at intervals of about the sound sources MS-L3-1 and MS-R302 of FIG.

  By arranging the live microphones LM_L12-1 and LM_R12-2 in this way, the positional relationship of the live microphones is the same as the positional relationship of the measurement microphones MM_L3-1 and MM_R3-2 in the first original sound field 1. become.

  The LM_L 12-1 and LM_R 12-2 respectively collect the sound uttered in the second original sound field 11 (s1), and collect the collected sound signals x_L (m) and x_R (m) as transmission means 21 and reception means. 22 to the reproduction signal generation apparatus 100.

<Reproduction signal generating apparatus 100>
FIG. 8 shows a functional block diagram of the reproduction signal generating apparatus 100. The reproduction signal generation device 100 includes a storage unit 130, a first calculation unit 111, a second calculation unit 112, a fifth calculation unit 115, a sixth calculation unit 116, a first addition unit 121, and a second addition unit 122. Including.

<Calculation means>
The first computing means 111 is a direct wave of the impulse response MS_R-MM_L with respect to the collected sound signal x_R (m) obtained from the live microphone LM_R12-2 arranged in the same positional relationship as the measurement microphone MM_R3-2. The component filter An _{MS_R-MM_L} (m) and the delay time filter Δ (m-Dn _{MS_R-MM_L} ) are convoluted by the following equation to obtain the first output signal y _{MS_R-MM_L} (m).
y _{MS_R-MM_L} (m) = x_R (m) * δ (m-Dn _{MS_R-MM_L} ) * An _{MS_R-MM_L} (m)

Similarly, the second calculation means 112 receives each impulse response MS_R− with respect to the collected sound signal x_R (m) obtained from the live microphone LM_R12-2 arranged in the same positional relationship as the measurement microphone MM_R3-2. A direct wave component filter An _{MS_R-MM_R} (m) of _{MM_R} and a delay time filter Δ (m-Dn _{MS_R-MM_R} ) are convolved to obtain a second output signal y _{MS_R-MM_R} (m).

Similarly, the fifth calculation means 115 and the sixth calculation means 116 respectively apply to the collected sound signal x_L (m) obtained from the live microphone LM_L12-1 disposed in the same positional relationship as the measurement microphone MM_L3-1. Direct wave component filters An _{MS_L-MM_L} (m), An _{MS_L-MM_R} (m) and delay time filters δ (m-Dn _{MS_L-MM_L} ), δ (m- Dn _{MS_L-MM_R} ) are respectively convolved to _{obtain a} fifth output signal y _{MS_L-MM_L} (m) and a sixth output signal y _{MS_L-MM_R} (m).

<Adding unit>
The first adder 121 adds the first output signal y _{MS_R-MM_L} (m) and the fifth output signal y _{MS_L-MM_L} (m), and outputs the reproduction signal y_L (m) to the speaker S_L 32-1.
y_L (m) = y _{MS_R-MM_L} (m) + y _{MS_L-MM_L} (m)

The second adder 122 adds the second output signal y _{MS_R-MM_R} (m) and the sixth output signal y _{MS_L-MM_R} (m), and outputs the reproduction signal y_R (m) to the speaker S_R 32-2.
y_R (m) = y _{MS_R-MM_R} (m) + y _{MS_L-MM_R} (m)

<Playback sound field 31>
In the reproduction sound field 31, speakers S_L32-1 and S_R32-2 are arranged on the left and right sides of the sound receiving point, respectively.

  The speakers S_L 32-1 and S_R 32-2 reproduce the input reproduction signals y_L (m) and y_R (m), respectively.

<Effect>
With such a configuration, effects similar to those of the first embodiment can be obtained in stereo reproduction.

<Modification>
Only parts different from the second embodiment will be described.

  FIG. 9 is a diagram for explaining the positional relationship between the sound source and the measurement microphone in the first original sound field.

  In this modification, measurement microphones MM_L3-1 and MM_R3-2 are arranged on the left and right sides of the dummy head (sound receiving point) 6, respectively.

  FIG. 10 is a diagram for explaining the sound collection / reproduction system 200.

  Live microphones LM_L12-1 and LM_R12-2 are arranged on the left and right sides of the dummy head installed in the second original sound field 11, respectively.

  By arranging the live microphones LM_L12-1 and LM_R12-2 in this way, the positional relationship of the live microphones is the same as the positional relationship of the measurement microphones MM_L3-1 and MM_R3-2 in the first original sound field 1. become.

  Headphone speakers S_L 32-1 and S_R 32-2 reproduce the input reproduction signals y_L (m) and y_R (m), respectively.

<Effect>
With such a configuration, effects similar to those of the second embodiment can be obtained in headphone playback.

<Third embodiment>
Only parts different from the first embodiment will be described.

<Pre-processing>
Hereinafter, a method for measuring the impulse response in the first original sound field will be described. FIG. 11 is a diagram for explaining the positional relationship between the sound source and the measurement microphone in the first original sound field.

  (1) First, a virtual sound receiving point 4 (so-called sweet spot) is set in the first original sound field 1.

  (2) The sound source MS_C2-1 is arranged on the stage 5 from the sound receiving point 4 in consideration of the arrangement of the speakers (see FIG. 12). The sound source MS_C2-1 is arranged in front of the sound receiving point 4.

  (3) A position where a speaker is arranged in a reproduction sound field 31 to be described later is set (see FIG. 12), and measurement microphones MM_L3-1 and MM_R3-2 are arranged on the left and right sides of the sound receiving point 4, respectively.

(4) Measure impulse responses from the sound source MS_C2-1 to each of the measurement microphones MM_L3-1 and MM_R3-2. Impulse responses from the sound source MS_C2-1 to the measurement microphones MM_L3-1 and MM_R3-2 are denoted as MS_C-MM_L and MS_C-MM_R, respectively. Then, from the measured impulse responses MS_C-MM_L, MS_C-MM_R, the direct wave component filters An _{MS_C-MM_L} (m), An _{MS_C-MM_R} (m) and delay time filters δ (m-Dn _{MS_C-MM_L} ), δ (m-Dn _{MS_C-MM_R} ) are generated and stored in the storage unit 130 in the reproduction signal generating apparatus 100.

<Sound Collection Playback System 200>
FIG. 12 is a diagram for explaining the sound collection / reproduction system 200. FIG. 13 shows a processing flow of the sound collection / reproduction system 200.

<Second original sound field 11>
A live microphone LM_C 12 is installed in the center of the second original sound field 11 on the stage 13.

  The LM_C 12 collects each sound uttered in the second original sound field 11 (s1), and outputs the collected sound signal x_C (m) to the reproduction signal generation apparatus 100 via the transmission unit 21 and the reception unit 22. To do.

<Reproduction signal generating apparatus 100>
FIG. 14 is a functional block diagram of the reproduction signal generation device 100. The reproduction signal generation device 100 includes a storage unit 130, a first calculation unit 111, a fifth calculation unit 115, and a first addition unit 121.

<Calculation means>
The first computing means 111 applies the direct wave component filter An _{MS_C-MM_L} (m) of the impulse response MS_C-MM_L and the delay time filter δ (m−m) to the collected sound signal x_C (m) obtained from the live microphone LM_C12. Dn _{MS_C-MM_L} ) is convolved with the following equation to obtain the first output signal y _{MS_C-MM_L} (m).
y _{MS_C-MM_L} (m) = x_C (m) * δ (m-Dn _{MS_C-MM_L} ) * An _{MS_C-MM_L} (m)

Similarly, the fifth calculation means 115 applies the direct wave component filter An _{MS_C-MM_L} (m) of each impulse response MS_C-MM_L, MS_C-MM_R to the collected sound signal x_C (m) obtained from the live microphone LM_C12. , An _{MS_C-MM_R} (m) and delay time filters δ (m-Dn _{MS_C-MM_L} ), δ (m-Dn _{MS_C-MM_R} ) are convoluted to obtain a fifth output signal y _{MS_C-MM_L} (m).

<Adding unit>
The first adder 121 adds the first output signal y _{MS_C-MM_L} (m) and the fifth output signal y _{MS_C-MM_L} (m), and outputs the reproduction signal y_C (m) to the speaker S_C 32.
y_C (m) = y _{MS_C-MM_L} (m) + y _{MS_C-MM_L} (m)

<Playback sound field 31>
In the reproduction sound field 31, a speaker S_C32 is arranged in front of the sound receiving point. The speaker S_C32 reproduces the input reproduction signal y_C (m).

<Other variations>
The present invention is not limited to the above-described embodiments and modifications. For example, the various processes described above are not only executed in time series according to the description, but may also be executed in parallel or individually as required by the processing capability of the apparatus that executes the processes. In addition, it can change suitably in the range which does not deviate from the meaning of this invention.

<Program and recording medium>
The reproduction signal generation apparatus described above can also be functioned by a computer. In this case, each process of a program for causing a computer to function as a target device (a device having the functional configuration shown in the drawings in various embodiments) or a process procedure (shown in each embodiment) is processed by the computer. A program to be executed by the computer may be downloaded from a recording medium such as a CD-ROM, a magnetic disk, or a semiconductor storage device or via a communication line into the computer, and the program may be executed.

Claims (8)

The direct wave component of the impulse response observed by a measurement microphone placed in the first original sound field so as to correspond to the sound source arranged in the first original sound field and the speaker arranged in the reproduced sound field, where m is a discrete time A storage step for storing a direct wave component filter An (m) representing the amplitude of the delay time filter δ (m−Dn) representing a δ function corresponding to the delay time Dn of the impulse response;
For a plurality of the measurement microphone positional relationship so that the same positional relationship with the second original sound field to arranged a plurality of sound pickup signals x obtained from commentary microphone (m), the direct wave component filter An operation step of convolving An (m) and the delay time filter δ (m-Dn),
Reproduction signal generation method. A reproduction signal generation method according to claim 1, comprising:
Furthermore, a first addition step, a second addition step, a third addition step and a fourth addition step,
A virtual sound receiving point is set in the first original sound field, and measurement microphones MM_LF, MM_RF, MM_LR and MM_RR are respectively provided at the left front, right front, left rear and right rear so as to surround the sound receiving point. It is assumed that the sound sources MS_L and MS_R are arranged outside the area formed by the four measurement microphones, and at the left front and right front of the sound receiving point, respectively.
In the second original sound field, live microphones LM_LF and LM_RF are arranged so as to have the same positional relationship as that of the measurement microphones MM_LF and MM_RF,
In the reproduction sound field, speakers S_LF, S_RF, S_LR, and S_RR are arranged at the left front, right front, left rear, and right rear, respectively, so as to surround the sound receiving point,
In the storing step, from the sound sources MS_L and MS_R and the measurement microphones MM_LF, MM_RF, MM_LR and MM_RR, impulse responses MS_L-MM_LF, MS_L-MM_RF, MS_L-MM_LR, MS_L-MM_RR, MS_R-MM_LF, Observe MS_R-MM_RF, MS_R-MM_LR, MS_R-MM_RR, direct wave component filter of each impulse response An _{MS_R-MM_LF} (m), An _{MS_R-MM_RF} (m), An _{MS_R-MM_LR} (m), An _{MS_R- MM_RR} (m), An _{MS_L-MM_LF} (m), An _{MS_L-MM_RF} (m), An _{MS_L-MM_LR} (m), An _{MS_L-MM_RR} (m) and delay time filter δ (m-Dn _{MS_R-MM_LF} ), δ (m-Dn _{MS_R-MM_RF} ), δ (m-Dn _{MS_R-MM_LR} ), δ (m-Dn _{MS_R-MM_RR} ), δ (m-Dn _{MS_L-MM_LF} ), δ (m-Dn _{MS_L-MM_RF} ), δ (m-Dn _{MS_L-MM_LR} ), δ (m-Dn _{MS_L-MM_RR} ) are stored,
In the calculation step, the direct wave component filters An _{MS_R-MM_LF} (m), An _{MS_R-MM_RF} (m), An _{MS_R-MM_LR} (m) for the collected sound signal x_RF (m) obtained from the live microphone LM_RF ), An _{MS_R-MM_RR} (m) and delay filter δ (m-Dn _{MS_R-MM_LF} ), δ (m-Dn _{MS_R-MM_RF} ), δ (m-Dn _{MS_R-MM_LR} ), δ (m-Dn _{MS_R- MM_RR} ), first output signal y _{MS_R-MM_LF} (m), second output signal y _{MS_R-MM_RF} (m), third output signal y _{MS_R-MM_LR} (m), fourth output signal y _{MS_R- MM_RR} (m) is obtained, and the direct wave component filters An _{MS_L-MM_LF} (m), An _{MS_L-MM_RF} (m), An _{MS_L-MM_LR} for the collected sound signal x_LF (m) obtained from the live microphone _{LM_LF} (m), An _{MS_L-MM_RR} (m) and delay time filter δ (m-Dn _{MS_L-MM_LF} ), δ (m-Dn _{MS_L-MM_RF} ), δ (m-Dn _{MS_L-MM_LR} ), δ (m-Dn _{MS_L-MM_RR} (m), fifth output signal y _{MS_L-MM_LF} (m), sixth output signal y _{MS_L-MM_RF} (m), seventh output signal y _{MS_L-MM_LR} (m), eighth output signal y _{MS_L-MM_RR} the (m) Because,
In the first addition step, the first output signal y _{MS_R-MM_LF} (m) and the fifth output signal y _{MS_L-MM_LF} (m) are added and output to the speaker S_LF,
In the second addition step, the second output signal y _{MS_R-MM_RF} (m) and the sixth output signal y _{MS_L-MM_RF} (m) are added and output to the speaker S_RF,
In the third addition step, the third output signal y _{MS_R-MM_LR} (m) and the seventh output signal y _{MS_L-MM_LR} (m) are added and output to the speaker S_LR,
In the fourth addition step, the fourth output signal y _{MS_R-MM_RR} (m) and the eighth output signal y _{MS_L-MM_RR} (m) are added and output to the speaker S_RR.
Reproduction signal generation method. A reproduction signal generation method according to claim 2, wherein
In the second original sound field, live microphones LM_RR and LM_LR are arranged so as to have the same positional relationship as that of the measurement microphones MM_LR and MM_RR on the left rear and right rear,
In the third addition step, the third output signal y _{MS_R-MM_LR} (m), the seventh output signal y _{MS_L-MM_LR} (m), and the sound pickup signal x_LR (m) obtained from the live microphone LM_LR Add and output to the speaker S_LR,
In the fourth addition step, the fourth output signal y _{MS_R-MM_RR} (m), the eighth output signal y _{MS_L-MM_RR} (m), and the collected sound signal x_RR (m) obtained from the live microphone LM_RR are obtained. Add and output to the speaker S_RR,
Reproduction signal generation method. A reproduction signal generation method according to claim 1, comprising:
And a first addition step and a second addition step,
Virtual reception points are set in the first original sound field, measurement microphones MM_L and MM_R are arranged on the left and right sides of the reception points, respectively, and sound sources MS_L are respectively provided on the left and right sides of the reception points. And MS_R are placed,
In the second original sound field, live microphones LM_R and LM_L are arranged so as to have the same positional relationship as that of the measurement microphones MM_L and MM_R,
In the reproduction sound field, speakers S_L and S_R are arranged on the left and right sides of the sound receiving point, respectively.
In the storing step, impulse responses MS_L-MM_L, MS_L-MM_R, MS_R-MM_L, MS_R-MM_R are observed from the sound sources MS_L and MS_R and the measurement microphones MM_L and MM_R, respectively, and each impulse response is directly Wave component filters An _{MS_R-MM_L} (m), An _{MS_R-MM_R} (m), An _{MS_L-MM_L} (m), An _{MS_L-MM_R} (m) and delay time filter δ (m-Dn _{MS_R-MM_L} ), δ ( m-Dn _{MS_R-MM_R} ), δ (m-Dn _{MS_L-MM_L} ), δ (m-Dn _{MS_L-MM_R} ),
In the calculation step, the direct wave component filters An _{MS_R-MM_L} (m), An _{MS_R of the} impulse responses MS_R-MM_L, MS_R-MM_R for the collected sound signal x_R (m) obtained from the live microphone _{LM_R. -MM_R} (m) and delay time filters δ (m-Dn _{MS_R-MM_L} ) and δ (m-Dn _{MS_R-MM_R} ) are convolved, respectively, and the first output signal y _{MS_R-MM_L} (m) and the second output signal y _{MS_R-MM_R} (m) is obtained, and the direct wave component filter An _{MS_L-MM_L} (m) of the impulse responses MS_L-MM_L and MS_L-MM_R is obtained for the sound pickup signal x_L (m) obtained from the live microphone LM_L. ), An _{MS_L-MM_R} (m) and delay time filters δ (m-Dn _{MS_L-MM_L} ), δ (m-Dn _{MS_L-MM_R} ) are convolved, respectively, and the fifth output signal y _{MS_L-MM_L} (m), 6 output signals y _{MS_L-MM_R} (m)
In the first addition step, the first output signal y _{MS_R-MM_L} (m) and the fifth output signal y _{MS_L-MM_L} (m) are added and output to the speaker S_L,
In the second addition step, the second output signal y _{MS_R-MM_R} (m) and the sixth output signal y _{MS_L-MM_R} (m) are added and output to the speaker S_R.
Reproduction signal generation method. The direct wave component of the impulse response observed by a measurement microphone placed in the first original sound field so as to correspond to the sound source arranged in the first original sound field and the speaker arranged in the reproduced sound field, where m is a discrete time A storage step for storing a direct wave component filter An (m) representing the amplitude of the delay time filter δ (m−Dn) representing a δ function corresponding to the delay time Dn of the impulse response;
A sound collection step of obtaining a collected sound signal x (m) from a plurality of multiple commentary microphone disposed on the second original sound field so that the same positional relationship and the positional relationship of the measurement microphone,
A calculation step of convolving the direct wave component filter An (m) and the delay time filter δ (m-Dn) with respect to the collected sound signal x (m),
A reproduction step of reproducing a reproduction signal including the convolved signal,
Sound collection playback method. The direct wave component of the impulse response observed by a measurement microphone placed in the first original sound field so as to correspond to the sound source arranged in the first original sound field and the speaker arranged in the reproduced sound field, where m is a discrete time A storage unit that stores a direct wave component filter An (m) representing the amplitude of the delay time filter δ (m−Dn) representing a δ function corresponding to the delay time Dn of the impulse response;
For a plurality of the measurement microphone positional relationship so that the same positional relationship with the second original sound field to arranged a plurality of sound pickup signals x obtained from commentary microphone (m), the direct wave component filter An operation means for convolving An (m) and the delay time filter δ (m-Dn),
Playback signal generator. The direct wave component of the impulse response observed by a measurement microphone placed in the first original sound field so as to correspond to the sound source arranged in the first original sound field and the speaker arranged in the reproduced sound field, where m is a discrete time A storage unit that stores a direct wave component filter An (m) representing the amplitude of the delay time filter δ (m−Dn) representing a δ function corresponding to the delay time Dn of the impulse response;
A plurality of commentary microphone disposed on the second original sound field so that the plurality of positional relationship similar positional relationship with the measurement microphone,
A calculation means for convolving the direct wave component filter An (m) and the delay time filter δ (m-Dn) with respect to the collected sound signal x (m) obtained from the live microphone,
A speaker for reproducing a reproduction signal including the convolved signal,
Sound collection and playback system. The program for making a computer perform each step of the reproduction | regeneration signal production | generation method in any one of Claims 1-4.

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