JP2023131663A - Audio signal processing device and audio signal processing method - Google Patents

Abstract

To reduce the amount of calculation for simulating reverberant sound.SOLUTION: An audio signal processing device according to an embodiment uses a reverberation filter corresponding to each of the channels from input audio signals of some of the channels from among the input audio signals of the plurality of channels to generate a reverberant audio signal corresponding to each of the plurality of channels. Furthermore, the audio signal processing device switches the audio signal of the reverberant sound in a time-divisional manner, mixes the audio signal based on the input audio signal with the audio signal of the plurality of output channels, and outputs the mixed audio signal.SELECTED DRAWING: Figure 6

Description

The present invention relates to an audio signal processing device and an audio signal processing method.

Reverb technology is conventionally known as a method of generating a three-dimensional sound field. Reverb technology is a method of reproducing a three-dimensional sound field by simulating reflected sound from a room, hall, etc. through signal processing and reproducing it from a speaker.

In addition, for example, a method is known in which a test sound output from a speaker is recorded with a microphone and the direction of the speaker is repeatedly changed, thereby adding an impulse response at the measured microphone placement position to create a reverberant sound source. (For example, see Patent Document 1).

Japanese Patent Application Publication No. 2017-090589

However, the conventional technique has a problem in that the amount of calculation required to simulate reverberant sound is large.

For example, in order to simulate reverberant sound using conventional techniques, reverb filters whose number is equal to the number of input channels multiplied by the number of output channels are required. As the number of reverb filters increases, the amount of calculation increases.

The present invention has been made in view of the above, and an object of the present invention is to provide an audio signal processing device and an audio signal processing method that can reduce the amount of calculation for simulating reverberation sound.

In order to solve the above-mentioned problems and achieve the objects, an audio signal processing device according to the present invention includes a control section that processes audio signals. The control unit calculates reverberation sound corresponding to each of the plurality of channels from the input audio signal of some of the inputted channels using a reverberation filter corresponding to each of the channels. Generate an audio signal. The control unit switches the audio signal of the reverberant sound in a time-divisional manner, mixes the audio signal based on the input audio signal with the audio signal of the plurality of output channels, and outputs the mixed audio signal.

According to the present invention, the amount of calculation for simulating reverberant sound can be reduced.

FIG. 1 is a diagram illustrating reverberation sound. FIG. 2 is a diagram illustrating a reverberation filter. FIG. 3 is a diagram showing an example of the configuration of the audio output system. FIG. 4 is a diagram showing a configuration example of an audio signal processing device. FIG. 5 is a diagram illustrating audio signal processing. FIG. 6 is a diagram illustrating reverberation processing. FIG. 7 is a flowchart showing the procedure of audio signal processing. FIG. 8 is a diagram illustrating audio signal processing. FIG. 9 is a diagram illustrating audio signal processing. FIG. 10 is a diagram illustrating audio signal processing. FIG. 11 is a diagram illustrating audio signal processing. FIG. 12 is a diagram showing a conventional method for creating a reverberation filter. FIG. 13 is a diagram illustrating conventional reverberation processing.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an audio signal processing device and an audio signal processing method disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below.

First, reverberation sound will be explained using FIG. 1. FIG. 1 is a diagram illustrating reverberation sound.

FIG. 1 is a diagram of the room 5 viewed vertically downward. As shown in FIG. 1, the user U is located near the center of the room 5.

It is assumed that the room 5 has a sound source Lch and a sound source Rch. Here, of the sound generated from the sound source Lch, the component in the direction of the user U directly reaches the user U as a direct sound.

Further, the sound generated from the sound source Lch is reflected on the wall of the room 5 and reaches the user U as a reflected sound. In addition, the reflected sound may further reflect off the walls.

The order is the number of times the reflected sound is reflected off the wall. For example, a reflected sound generated by direct sound reflecting off a wall only once is a first-order reflected sound. The reflected sound generated by the first-order reflected sound reflecting off the wall one more time is the second-order reflected sound.

Here, a reflected sound whose order is less than a certain number (for example, 3) is referred to as an early reflected sound. Further, high-order reflected sounds whose order is a certain number or more, and sound in which high-order reflected sounds are mixed are called reverberant sounds.

To the user U, the reverberant sounds seem to arrive randomly from all around.

FIR filters and IIR filters are known as reverberation filters for simulating reverberant sound.

For example, an FIR (Finite Impulse Response) filter is designed based on actually measured impulse response data. Further, an IIR (Infinite Impulse Response) filter is designed with a comb filter and an all-pass filter.
Reference: A.R.I. Co., Ltd., “Sound Digital Signal Processing Reverberator, Reverberation Device” (URL: http://www.ari-co.co.jp/service/soft/reverb-2.htm)

As a method for creating a reverberation filter, the method shown in FIG. 12 can be considered. FIG. 12 is a diagram showing a conventional method for creating a reverberation filter.

In the method shown in FIG. 12, a multipoint directional microphone is placed near the center of the room. By using a multipoint directional microphone, it becomes possible to measure the impulse response for each direction and create a reverberation filter (FIR filter or IIR filter) for each direction based on the measured impulse response.

Here, it is assumed that speakers that output audio in the sound reproduction space are placed at positions of 0°, 45°, 135°, 225°, and 315° with respect to the front of the user (0°). That is, the number of output channels is five.

Further, it is assumed that the input audio signal is a stereo 2ch sound source (L and R). That is, the number of input channels is two.

In this case, in the conventional method, reverberation filters corresponding to 0°, 45°, 135°, 225°, and 315° are required for each of the Rch and Lch. The number of reverberation filters required in this case is 2 (number of input channels)×5 (number of output channels)=10.

In the conventional method, reverberation processing as shown in FIG. 13 is performed using ten created reverberation filters. FIG. 13 is a diagram illustrating conventional reverberation processing.

H _R,0° , H _R,45° , H _{R,135°, H R, 225°} , H _R,315° , H _{L,0°, H L, 45°, H L, 135°} , H _{L , 225°} and H _{L, 315°} are reverberation filters.

In this way, the conventional method requires many reverberation filters, which increases the amount of calculations required to simulate reverberation.

Note that if a sound field inverse filter that cancels the transfer function of the sound reproduction space is set on the output audio signal, reverberation reproducibility will be further improved. In this way, it may be desirable to reduce the amount of calculations required for filtering using the reverberation filter and allocate that amount to other processing.

Here, the reverberation filter of the embodiment will be described using FIG. 2. FIG. 2 is a diagram illustrating a reverberation filter.

As shown in FIG. 2, the reverberation filter of the embodiment is created using one omnidirectional microphone provided in a room 5, unlike a conventional reverberation filter.

That is, in the embodiment, one reverberation filter is created for each of the Lch and Rch sound sources. On the other hand, in the example of FIG. 12, five reverberation filters are created for each of Lch and Rch.

Further, as described above, reverberant sound is generated when direct sound is reflected off walls a certain number of times. As shown in FIG. 2, the sound pressure decreases in the order of direct sound, early reflection sound, and reverberation sound, and the density in the time direction increases.

A reverberation filter is a filter that expresses changes in the sound pressure of reverberant sound over time.

Note that the reverberation filter used in the embodiment may be one created according to the room 5 by the method shown in FIG. 2, or may be an existing reverberation filter created by simulation or the like.

The audio output system according to the embodiment will be described using FIG. 3. FIG. 3 is a diagram showing an example of the configuration of the audio output system.

As shown in FIG. 3, the audio output system 1 includes an audio signal processing device 10 and a plurality of speakers (speaker Ce, speaker FL, speaker RL, speaker FR, and speaker RR) arranged at predetermined positions.

The audio signal processing device 10 controls the audio output of the speaker. The audio signal processing device 10 outputs an audio signal to a speaker, and causes the speaker to output audio based on the audio signal.

Furthermore, the audio signal processing device 10 outputs a reverberant audio signal to the speaker together with the direct audio signal. Then, the speaker outputs audio including reverberant sound based on the audio signal output by the audio signal processing device 10. This allows the audio output system 1 to simulate reverberation.

The speaker may be placed inside a room of a building or inside a vehicle. Moreover, the speaker may be placed outdoors.

Furthermore, the audio signal processing device 10 is connected to a speaker by wire or wirelessly. The audio signal processing device 10 may be an information processing device such as a personal computer or a smartphone.

Furthermore, when the speaker is placed inside the vehicle, the audio signal processing device 10 may be realized as a part of the function of an audio system installed in the vehicle or a car navigation system.

Furthermore, the audio signal processing device 10 may be a server connected to a speaker via the Internet.

The audio signal processing device 10 also outputs audio signals to each of the speaker Ce, speaker FL, speaker RL, speaker FR, and speaker RR. Therefore, the number of output channels of the audio signal processing device 10 is five.

It is also assumed that audio signals from a stereo 2ch sound source (L and R) are input to the audio signal processing device 10. Therefore, the number of input channels of the audio signal processing device 10 is two.

FIG. 4 is a diagram showing a configuration example of an audio signal processing device. As shown in FIG. 4, the audio signal processing device 10 includes an input/output section 11, a storage section 12, and a control section 13.

The input/output unit 11 is an interface for inputting and outputting audio signals. For example, the input/output unit 11 outputs audio signals to each speaker.

The control unit 13 and storage unit 12 of the audio signal processing device 10 are, for example, a computer or various devices having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), a flash memory, an input/output port, etc. Realized by a circuit.

The CPU of the computer functions as the signal processing section 131 and the audio output control section 132 of the control section 13 by reading and executing a program stored in a ROM, for example.

Furthermore, the storage unit 12 corresponds to a RAM or a flash memory. The RAM and flash memory can store filter information 121, audio data 122, information on various programs, and the like.

Note that the audio signal processing device 10 may acquire the above-mentioned programs and various information via another computer or a portable recording medium connected via a wired or wireless network.

Filter information 121 is information regarding a reverberation filter. The filter information 121 includes parameters of the reverberation filter and the like.

The audio data 122 is the source data of the audio to be output. The audio data 122 is, for example, an audio file.

Note that the audio signal processing device 10 may output an audio signal based on the audio data 122, or may output an audio signal based on data input in real time via the input/output unit 11.

The signal processing unit 131 generates an output signal based on the input audio signal. For example, the output audio signal is a mixture (synthesis) of a direct sound audio signal and a reverberant sound audio signal.

Audio signal processing by the signal processing unit 131 will be explained using FIG. 5. First, input audio signals of two channels, L and R, are input to the signal processing section 131. However, the input audio signal of one channel may be input to the signal processing unit 131.

Next, the signal processing unit 131 performs upmixing of the input audio signal and distributes the input audio signal to each channel through which the audio signal is output (step S1).

Thereby, the signal processing unit 131 generates output audio signals of a plurality of channels, the number of which is greater than the number of channels of the input audio signal, from the input audio signal of one or more input channels.

This makes it possible to reproduce reverberant sound even if the number of input audio signal channels is limited.

In the example of FIG. 5, the signal processing unit 131 generates 5-channel audio signals of Ce, FL, RL, FR, and RR on the output side by upmixing from the 2-channel input audio signals of L and R on the input side. do.

Note that the output side channels Ce, FL, RL, FR, and RR are channels corresponding to the speaker Ce, speaker FL, speaker RL, speaker FR, and speaker RR, respectively.

Next, the signal processing unit 131 performs reverberation processing on the input audio signal (step S2). Then, the signal processing unit 131 mixes the reverberant audio signal obtained by the reverberation processing with at least one of the five channels of audio signals on the output side, and outputs the mixed signal (step S3).

Note that the processing shown in FIG. 5 is performed for each predetermined number of samples in the audio signal or for each frame. Therefore, the signal processing unit 131 performs upmixing and reverberation processing every time a predetermined time elapses.

Further, the signal processing unit 131 mixes the reverberant audio signal with the audio signals of some channels selected in the reverberation process, rather than with the audio signals of all channels on the output side.

For example, the reverberant audio signal at time t ₁ may be mixed with only the audio signals of channel RR and channel FL, and the reverberant audio signal at time t ₁ +1 may be mixed only with the audio signals of channel Ce and channel RL. .

In this way, the audio signal (output audio signal) of the output side channel where the reverberant audio signal is synthesized is switched in a time-division manner.

As described above, the signal processing unit 131 uses the reverberation filters corresponding to each of the channels to generate reverberant sound from the input audio signals of some channels among the input audio signals of a plurality of input channels. Generate a signal. Further, the signal processing unit 131 switches the reverberant audio signal in a time-division manner, mixes it with the audio signal of the output audio signal channel, and outputs the mixed signal.

Reverberation processing will be explained in detail using FIG. 6. FIG. 6 is a diagram illustrating reverberation processing.

In the reverberation process, a reverberation filter _HL and a reverberation filter _HR are used. In this way, the number of reverberation filters used in reverberation processing is equal to the number of channels on the input side.

The signal processing unit 131 filters the input audio signal of channel L using the reverberation filter _HL to generate a reverberant audio signal (step S21).

Then, the signal processing unit 131 selects one of the channels on the output side using the selector, and outputs the reverberant audio signal to the selected channel (step S22).

In this way, the signal processing unit 131 selects one of the channels corresponding to a plurality of speakers and to which an audio signal based on the input audio signal is input.

Note that the audio signal of the reverberant sound output here is used for mixing in step S3 of FIG. 5.

Similarly, the signal processing unit 131 filters the input audio signal of channel R using the reverberation filter _HR to generate a reverberant audio signal (step S23).

Then, the signal processing unit 131 selects one of the channels on the output side using the selector, and outputs the reverberant audio signal to the selected channel (step S24).

In this way, the signal processing unit 131 uses reverberation filters that correspond one-to-one to each channel of the input audio signal (input side channel) to generate reverberant sound corresponding to each input side channel. Generate an audio signal.

In this way, the embodiment allows reverberant sound to be reproduced with a minimum number of reverberation filters.

The selector is a process (program) for selecting an output channel. For example, the roulette selection shown in FIG. 6 is an image of selector processing. Further, it is assumed that numbers 1 to 6 correspond to channels Ce, FL, RL, FR, and RR.

The signal processing unit 131 time-divisionally switches the channel of the audio signal into which the reverberant audio signal is mixed, depending on the selection result by the selector.

For example, the signal processing unit 131 randomly switches the channel of the audio signal into which the reverberant audio signal is mixed.

This makes it possible to reproduce the feeling that reverberant sounds arrive randomly from all around.

In this case, the selector randomly selects one of the numbers 1 to 6, like a roulette selection.

Further, the probability of each number being selected may be equal or different.

For example, as shown in Figure 3, in the case of an arrangement where there are three speakers in front of the user and two speakers behind the user, if all speakers are selected with equal probability, the reverberant sound from the rear There are cases where the image becomes unnatural.

Therefore, the selection probability may be set to 1/6 for Ce, FL, and FR, and the selection probability may be set to 1/4 for RL and RR, thereby intentionally increasing the reverberant sound from the rear. Furthermore, the probability of speakers being selected may be changed not only between the front and rear but also between the left and right.

Further, for example, the signal processing unit 131 switches the channels of the audio signal into which the audio signal of the reverberant sound is mixed in an order according to a predefined rule.

This allows the selector to be executed with simple processing.

In this case, the selector is set in the order of 1, 2, 3, 4, 5, 6, 1, etc., for example, according to the rule "in ascending order of numbers (however, if you selected the largest number last time, select the smallest number)". to select the number.

Further, for example, the signal processing unit 131 switches the channels of the audio signal into which the audio signal of the reverberant sound is mixed, according to an arrangement in which each channel is arranged with duplication allowed.

This allows the designer's intention to be reflected in channel selection.

In this case, the selector refers to the elements of an array such as "3, 1, 2, 4, 3, 6, 1, 5, . . ." in order of index and selects them.

The audio output control unit 132 outputs the audio signal generated by the signal processing unit 131 to the speaker via the input/output unit 11. The audio output control unit 132 outputs the audio signal mixed in step S3 of FIG. 5 to the corresponding speaker.

The procedure of audio signal processing will be explained using FIG. 7. FIG. 7 is a flowchart showing the procedure of audio signal processing.

First, as shown in FIG. 7, the audio signal processing device 10 upmixes audio signals of one or more channels to a plurality of speakers (step S101). Note that if the number of channels on the input side and the number of channels on the output side are equal, step S101 may be omitted.

Here, the audio signal processing device 10 substitutes 1 for k (step S102). Note that k is an index corresponding to a channel on the input side. Further, N is the maximum value of k.

For example, when audio signals of two channels, L and R, are input, N is 2, and k is 1 and 2.

The audio signal processing device 10 filters the audio signal of the k-th channel using the reverberation filter corresponding to the k-th channel, and generates a reverberation signal (step S103). In this way, each channel has a one-to-one corresponding reverberation filter.

Next, the audio signal processing device 10 selects one of the plurality of speakers (step S104). Then, the audio signal processing device 10 mixes the reverberation signal with the audio signal of the selected speaker (step S105).

Here, the audio signal processing device 10 determines whether k=N (step S106). If k=N (step S106, Yes), the audio signal processing device 10 proceeds to step S108.

Then, the audio signal processing device 10 causes the speaker to output audio based on the audio signal (step S108). The audio signal here is a combination of a direct sound audio signal and a reverberant sound audio signal.

If k=N is not the case (step S106, No), the audio signal processing device 10 increases k by 1 (step S107), and returns to step S103.

As described above, the audio signal processing device 10 according to the embodiment uses reverberation filters corresponding to each channel from the input audio signals of some channels among the input audio signals of a plurality of input channels. Then, reverberant sound audio signals corresponding to each of the plurality of channels are generated. Furthermore, the audio signal processing device 10 switches the audio signal of reverberation sound in a time-divisional manner, and mixes the audio signal based on the input audio signal with the audio signal of a plurality of output channels and outputs the mixed signal.

In the embodiment, the number of reverberant sound filters for simulating reverberant sound is reduced to the same number as the number of channels on the input side. In this way, according to the embodiment, the amount of calculations for simulating reverberant sound can be reduced.

There are various combinations of the number of reverberation filters, the number of input channels, and the number of output channels to which the embodiments can be applied, including those described above.

(Pattern A: Number of input channels = number of output channels, number of reverberation filters < number of input channels)
As shown in FIG. 8, when the number of input channels and the number of output channels are equal, the signal processing unit 131 performs reverberation processing using fewer reverberation filters than the number of input channels. FIG. 8 is a diagram illustrating audio signal processing.

In the example of FIG. 8, the number of input channels and the number of output channels are both five. Further, in the example of FIG. 8, the reverberation filter is only the reverberation filter _HR corresponding to the input channel R, so the number of reverberation filters is one.

In pattern A, the signal processing unit 131 uses reverberation filters corresponding to each of the channels from the input audio signals of some of the input channels of the input audio signals of the plurality of channels. A reverberant sound audio signal corresponding to the reverberant sound is generated, and the reverberant sound audio signal is switched in a time-division manner so that the audio signal based on the input audio signal is mixed with the audio signals of the plurality of output channels and output.

In the example of FIG. 8, the signal processing unit 131 selects the input audio signal of one input channel R from among the input audio signals of five input channels (R, L, C, RR, RL). Using the reverberation filter H _R corresponding to the reverberation filter H Then, the audio signal based on the input audio signal is mixed with the audio signals of the five output channels (R, L, C, RR, RL) and output (step S311).

Further, for example, when the number of reverberation filters is 3 in pattern A, the signal processing unit 131 selects three input channels among the input audio signals of five input channels (R, L, C, RR, RL). From the R and LC input audio signals, the five channels (R, L, C, RR _, RL) are extracted using reverberation filters HR, HL, and _HC corresponding to the input channels _R, L, and C, respectively. The reverberant sound audio signals corresponding to the respective reverberant sound signals are generated, and the reverberant sound audio signals are time-divisionally switched to five output channels (R, L, C, RR, RL) and output it.

In pattern A, when the number of input channels is N (N≧1), the signal processing unit 131 can generate a reverberation-processed audio signal from the input audio signals of 1 to N−1 input channels.

(Pattern B: Number of input channels < Number of output channels, Number of reverberation filters ≦ Number of input channels)
As shown in FIG. 9, when the number of output channels is greater than the number of input channels, the signal processing unit 131 performs upmixing of the input audio signal (step S321). Further, the signal processing unit 131 performs reverberation processing using reverberation filters whose number is equal to or less than the number of input channels (step S322). FIG. 9 is a diagram illustrating audio signal processing. Note that the example described with reference to FIG. 6 and the like corresponds to pattern B.

In the example of FIG. 9, the number of input channels is two and the number of output channels is five. Further, in the example of FIG. 9, the reverberation filter is only the reverberation filter _HR corresponding to the input channel R, so the number of reverberation filters is one.

In pattern B, the signal processing unit 131 generates output audio signals of a plurality of channels, which is greater than the number of channels of the input audio signal, from the input audio signal of one or more input channels, and A reverberation filter corresponding to each of at least one channel is used to generate a reverberant sound audio signal, and the reverberant sound audio signal is switched in a time-sharing manner to be mixed with the output audio signals of multiple channels and output. .

In the example of FIG. 9, the signal processing unit 131 converts the input audio signals of the two input channels (R, L) into output audio signals of five channels, which is more than the number of channels of the input audio signals, which is two. (upmix) (step S321), generates an audio signal of reverberant sound using a reverberation filter _HR corresponding to at least one channel (R) of the input audio signal, and mixes the audio signal of reverberant sound with time. The signals are switched in a divided manner to mix and output the output audio signals of the five channels (R, L, C, RR, RL) (step S322).

Further, for example, when the number of input channels is 3 and the number of reverberation filters is 2 in pattern A, the signal processing unit 131 extracts the input audio signals from the input audio signals of the three input channels (R, L, C). A reverberation filter that generates an output audio signal of five channels (upmix), which is more than the number of channels of the audio signal, which is three, and that corresponds to each of at least one channel (two R and L) of the input audio signal. A reverberant audio signal is generated using H _R and _HL , and the reverberant audio signal is time-divisionally switched to output audio signals of five channels (R, L, C, RR, RL). Mix and output.

In pattern B, when the number of input channels is N (N≧1), the signal processing unit 131 can generate a reverberation-processed audio signal from the input audio signals of 1 to N−1 input channels.

(Pattern C: Number of reverberation filters < Number of input channels (downmix))
As shown in FIGS. 10 and 11, the signal processing unit 131 performs reverberation processing on the second number of audio signals obtained by mixing down the input audio signals of the first number of input channels. You can also do this. 10 and 11 are diagrams for explaining audio signal processing.

In pattern C, the signal processing unit 131 uses a reverberation filter to generate a reverberant audio signal from an audio signal obtained by mixing input audio signals of at least two channels among input audio signals of a plurality of input channels. The audio signal of the reverberant sound is generated and switched in a time-divisional manner, and the audio signal based on the input audio signal is mixed with the audio signals of the plurality of output channels and output.

FIG. 10 is an example where the number of input channels and the number of output channels are equal. In this case, the signal processing unit 131 mixes (downmixes) the input audio signals of two channels (R, L) among the input audio signals of the five input channels (R, L, C, RR, RL). ) is used to generate a reverberant audio signal using a reverberation filter _H (R, L, C, RR, RL) is mixed with the audio signal and output (step S331).

FIG. 11 is an example where the number of output channels is greater than the number of input channels. In this case, the signal processing unit 131 outputs an audio signal obtained by mixing (downmixing) the input audio signals of the two channels (R, L) among the input audio signals of the two channels (R, L) that have been input. A reverberant sound signal is generated using the reverberation filter _H , RR, RL) and output the mixed signal (step S342). In this case, the signal processing unit 131 generates output audio signals of five channels, which is more than the number of channels of the input audio signal (2), from the input audio signals of the two input channels (R, L). Generate (upmix) (step S341).

In pattern C, when the number of input channels is N (N≧2), the signal processing unit 131 can generate a reverberation-processed audio signal by downmixing the input audio signals of 2 to N input channels. can.

The pattern A, pattern B, and pattern C that have been described so far have in common that the number of reverberation filters is smaller than the number of output channels. According to embodiments, the number of reverberation filters can be at least less than the number of output channels. In particular, according to the embodiment, when the number of input channels is less than or equal to the number of output channels, the number of reverberation filters can be reduced to the number of input channels or less (however, the number of reverberation filters<the number of output channels).

Further advantages and modifications can be easily deduced by those skilled in the art. Therefore, the broader aspects of the invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various changes may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Ce, FL, RL, FR, RR Speaker U User 1 Audio output system 5 Room 10 Audio signal processing device 11 Input/output section 12 Storage section 13 Control section 121 Filter information 122 Audio data 131 Signal processing section 132 Audio output control section

Claims (8)

Equipped with a control unit that processes audio signals,
The control unit includes:
Out of input audio signals of a plurality of input channels, reverberant sound audio signals corresponding to each of the plurality of channels are generated from input audio signals of some channels using reverberation filters corresponding to each of the channels. generate,
An audio signal processing device that switches the audio signal of the reverberant sound in a time-divisional manner and outputs the audio signal based on the input audio signal mixed with audio signals of a plurality of output channels. Equipped with a control unit that processes audio signals,
The control unit includes:
Generating output audio signals of a plurality of channels, the number of which is greater than the number of channels of the input audio signal, from the input audio signal of one or more input channels;
generating a reverberant audio signal using a reverberation filter corresponding to each of the at least one channel of the input audio signal;
An audio signal processing device that switches the audio signal of the reverberant sound in a time-divisional manner, mixes it with the output audio signals of the plurality of channels, and outputs the mixed signal. Equipped with a control unit that processes audio signals,
The control unit includes:
Generating a reverberant audio signal using a reverberation filter from an audio signal obtained by mixing input audio signals of at least two channels among input audio signals of a plurality of input channels;
An audio signal processing device that switches the audio signal of the reverberant sound in a time-divisional manner and outputs the audio signal based on the input audio signal mixed with audio signals of a plurality of output channels. The audio signal processing device according to claim 1, wherein the control unit randomly switches a channel of an audio signal into which the audio signal of the reverberant sound is mixed. The audio signal processing device according to claim 1, wherein the control unit switches channels of audio signals into which the audio signal of the reverberant sound is mixed in an order according to a predefined rule. The audio signal processing device according to claim 1, wherein the control unit switches the channels of the audio signal into which the audio signal of the reverberant sound is mixed in accordance with an arrangement in which each channel is arranged to allow duplication. Equipped with a control unit that processes audio signals,
The control unit includes:
Generating a reverberant audio signal corresponding to each of the channels using a reverberation filter that corresponds one-to-one to each channel of the input audio signal,
Selecting one of the channels corresponding to a plurality of speakers and into which an audio signal based on the input audio signal is input,
An audio signal processing device that mixes the reverberant sound audio signal with the audio signal input to the selected channel. Generating a reverberant audio signal corresponding to each of the plurality of channels from the inputted audio signal of the plurality of channels using a reverb filter corresponding to each of the channels,
An audio signal processing method in which a computer executes a process of switching the reverberant sound audio signal in a time-divisional manner and mixing it with the audio signal of any one of the plurality of channels to be output.

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