Audio mixer and method for processing an audio signal

Abstract

To provide an audio mixer and an acoustic signal processing method with which it is possible for users to easily specify a localization position in a three-dimensional space of each channel.SOLUTION: Provided is an audio mixer comprising: a user interface for supplying a first parameter that indicates a position in the lateral direction and a second parameter that indicates an intra-head localization and / or an out-of-head localization, with respect to each channel; a panner for panning the acoustic signal of each channel in accordance with the first parameter and generating a plurality of first stereo signals; a first adder for mixing the first stereo signals of one or more channels among the plurality of channels, which the second parameter specifies an out-of-head location for, and generating second stereo signals; a localization processing unit for applying three-dimensional localization processing to the second stereo signals and generating a third stereo signals; a second adder for mixing the first stereo signals of a channel for which intra-head localization is specified and the third stereo signals and generating fourth stereo signals; and an output circuit for outputting the fourth stereo signals.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an audio mixer for mixing audio signals and a method for processing audio signals in the audio mixer. [Background technology]

[0002] Conventionally, when performing on stage, each performer monitors the performance sound, which is a mixture of multiple sound signals, through earphones or headphones. In content production, producers may apply in-head localization processing and out-of-head localization processing (hereinafter also referred to as three-dimensional localization processing) to each sound signal for viewers using headphones (see Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-188450 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, out-of-head localization processing has hardly been used for monitoring performances on stage. Out-of-head localization processing is performed using a transfer function generally called a head-related transfer function (HRTF), which represents characteristics determined by the shape of the head. In normal out-of-head localization processing, first, each sound signal input to multiple input channels is divided into multiple groups and mixed, and then the mixed signal of each group obtained is localized at a desired position in three-dimensional space using the head-related transfer function. If this is to be used as is for monitoring on stage, there is a problem that the processing requires many parameters to be set, and it is difficult for the mixer operator to grasp where the sound signal of each channel is localized. In addition, there is a problem that the operation method of the audio mixer is significantly different between cases where out-of-head localization processing is not performed and cases where it is performed, making it difficult for the operator to handle it.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an audio mixer and an audio signal processing method that allow a mixer operator to easily specify the position of each channel in three-dimensional space. [Means for solving the problem]

[0006] The audio mixer according to the present disclosure includes a user interface that supplies, for each of a plurality of channels, a first parameter indicating a position in a left-right direction and a second parameter specifying at least one of in-head localization and out-of-head localization in response to an operation by an operator; a panner that pans an acoustic signal of each channel in response to the first parameter to generate a plurality of first stereo signals of the plurality of channels; a first adder that mixes the first stereo signals of one or more channels of the plurality of channels, the second parameter specifying out-of-head localization, to generate a first second stereo signal; a localization processing unit that performs three-dimensional localization processing on the second stereo signal to generate a second third stereo signal; a second adder that mixes the first stereo signals of one or more channels of the plurality of channels, the second parameter specifying in-head localization, and the second third stereo signal to generate a fourth stereo signal; and an output circuit that outputs the fourth stereo signal.

[0007] An acoustic signal processing method according to the present disclosure includes: supplying, for each channel of a plurality of channels, a first parameter indicating a position in a left-right direction and a second parameter specifying at least one of in-head localization and out-of-head localization in response to an operation by an operator; panning the acoustic signals of each channel in response to the first parameter to generate a plurality of first stereo signals of the plurality of channels; mixing the first stereo signals of one or more channels of which the second parameter specifies out-of-head localization in the plurality of channels to generate a first second stereo signal; performing three-dimensional localization processing on the second stereo signal to generate a second third stereo signal; mixing the first stereo signals of one or more channels of which the second parameter specifies in-head localization in the plurality of channels with the second third stereo signal to generate a fourth stereo signal; and outputting the fourth stereo signal. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram of a monitor system according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the operation panel. [Diagram 3] FIG. 3 is a functional block diagram of the input channels and the mix channel. [Figure 4] FIG. 4 is a diagram showing a schematic diagram of the positional relationship of the sound image localization for each channel. [Diagram 5] FIG. 5 is a block diagram of an audio mixer according to the second embodiment. [Figure 6] FIG. 6 is a block diagram of an audio mixer including a fifth adder and a sixth adder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] The first embodiment will be described below with reference to the drawings. Fig. 1 is a block diagram of a monitor system 100 including an audio mixer according to the first embodiment. As shown in Fig. 1, the monitor system 100 includes an audio mixer and an in-ear monitor 102. The audio mixer includes a user interface 104, an input channel 106, a mix channel 108, a first adder 110, a localization processing unit 112, a second adder 114, an output circuit 116, and a transmitter 118. The performer may monitor using headphones instead of the in-ear monitor 102.

[0010] The user interface 104 receives from the operator a first parameter indicating a position in the left-right direction and a second parameter specifying at least one of head localization and head outside localization for each channel among the multiple channels. Specifically, for example, a schematic diagram showing an example of an operation panel that is the user interface 104 of the audio mixer shown in FIG. 2 will be used for explanation.

[0011] The user interface 104 includes a plurality of channel strips 202 corresponding to the input channels 106 and the mix channels 108. Each channel strip 202 includes a plurality of controls (also called operators), and Fig. 2 shows an example in which each channel strip 202 includes a first control 104A to a third control 104C. Each control is a variety of keys, buttons, rotary encoders, sliders, etc., for accepting operations on the audio mixer.

[0012] The first control 104A receives a first parameter indicating a left-right position from the operator for each channel. For example, the first control 104A is a knob or a rotary encoder. The operator performs a rotation operation on the first control 104A according to a desired left-right localization position. By accepting the operation, the first control 104A supplies a first parameter according to the angle of the knob or rotary encoder.

[0013] The second control 104B receives a second parameter that specifies at least one of in-head localization and out-of-head localization. Specifically, for example, the second control 104B is a switch. The operator performs a switching operation on the switch of each input channel 106 according to either the desired in-head localization or out-of-head localization. By accepting the operation, the second control 104B supplies a second parameter that specifies whether the first stereo signal is to be input to the first adder 110 or the second adder 114 for each channel. For example, in FIG. 1, the second controls 104B corresponding to the first input channel 106A, the second input channel 106B, and the fourth input channel 106D all supply the second parameter that indicates out-of-head localization. Also, the second controls 104B corresponding to the third input channel 106C and the fifth input channel 106E all supply the second parameter that indicates in-head localization.

[0014] The second parameter may specify the level balance between the first stereo signal and the second adder 110 when the first stereo signal is input to the first adder 110 and the second adder 114 for each input channel 106. For example, the second control 104B may be a knob, and the position indicated by the knob's marker may correspond to the level balance. Specifically, when the knob's marker is at the center, the first stereo signal may be input to the first adder 110 and the second adder 114 at a ratio of 5:5. When the knob's marker is at a position 30% from the left, the first stereo signal may be input to the first adder 110 and the second adder 114 at a ratio of 3:7.

[0015] The third control 104C receives a third parameter indicating the volume of each channel from the operator. Specifically, for example, the third control 104C is a slider. The operator performs a sliding operation on the slider according to the desired volume. The third control 104C supplies the third parameter indicating the volume by accepting the operation.

[0016] The number of controls included in each channel strip 202 is not limited to three, and may be two or four or more, as long as it includes at least the first control 104A and the second control 104B.

[0017] Each of the input channels 106 and the mix channel 108 performs various signal processing on the input monaural or stereo signal, and then outputs a processed stereo signal. A stereo signal is composed of a right channel signal and a left channel signal. Specifically, FIG. 3 is a functional block diagram of the input channels 106 and the mix channel 108. As shown in FIG. 3, the input channels 106 and the mix channel 108 include a compressor 302, an equalizer 304, a fader 306, and a panner 308. Note that the mix channel 108 may be omitted.

[0018] The compressor 302 performs dynamic level adjustment processing on the input signal according to a threshold and ratio specified by an operator. The equalizer 304 performs amplification and attenuation processing on the frequency range specified by an operator on the signal processed by the compressor 302. The fader 306 performs volume adjustment processing on the processing output by the equalizer 304 according to a third parameter. The panner 308 performs panning processing on the signal processed by the fader 306 according to a first parameter to generate a first stereo signal.

[0019] Here, there are a plurality of input channels 106. A plurality of first stereo signals are generated according to the number of acoustic signals input to the input channels 106. Then, the plurality of first stereo signals are output to the first adder 110 or the second adder 114 for each input channel 106 according to the second parameter.

[0020] For example, in FIG. 1, the input channels 106 include five input channels 106 from the first input channel 106A to the fifth input channel 106E. For example, sound signals transmitted from a kick, a snare, a bass, a guitar, and a microphone are input to each input channel 106. In the above example, the second controls 104B of the first input channel 106A, the second input channel 106B, and the fourth input channel 106D all receive the second parameter representing out-of-head localization. Therefore, the sound signals input to the first input channel 106A, the second input channel 106B, and the fourth input channel 106D are subjected to left-right localization processing according to the first parameter corresponding to each input channel 106, and then output to the first adder 110. On the other hand, the second controls 104B of the third input channel 106C and the fifth input channel 106E all receive the second parameter representing in-head localization. Therefore, the acoustic signals input to the third input channel 106C and the fifth input channel 106E are subjected to left / right localization processing according to the first parameter corresponding to each input channel 106, and then output to the second adder 114.

[0021] The first adder 110 mixes first stereo signals of one or more channels whose second parameters specify out-of-head localization among the multiple channels to generate one second stereo signal. Specifically, for example, the first adder 110 may be any bus such as a mixing bus, a stereo bus, or a matrix bus, and mixes signals input from multiple input channels 106. Here, a bus is one component of an audio mixer that receives multiple audio signals and outputs the mixed result of the audio signals. A stereo bus independently mixes the audio signals of the right channel and the left channel, and outputs one audio signal resulting from the mixing of the right channel and one audio signal resulting from the mixing of the left channel. In the above example, the first adder 110 mixes the first stereo signals output from the first input channel 106A, the second input channel 106B, and the fourth input channel 106D to generate one second stereo signal. The second stereo signal is output to the mix channel 108. The mix channel 108 performs various signal processing on the second stereo signal, and then outputs the processed second stereo signal to the localization processing unit 112.

[0022] The localization processing unit 112 performs three-dimensional localization processing on the second stereo signal to generate a second third stereo signal. The localization processing unit 112 performs three-dimensional localization processing on each of the right channel signal and the left channel signal included in the second stereo signal to generate a second third stereo signal. Specifically, the localization processing unit 112 performs a convolution operation on a predetermined head-related transfer function coefficient for the right channel signal and the right channel signal included in the second stereo signal, and generates a third stereo signal related to the right channel by adding a transfer characteristic of a sound arriving from a virtual localization position of the right channel to both ears of a listener. The localization processing unit 112 performs the same processing on the left channel signal to generate a third stereo signal related to the left channel. The generated second third stereo signal is output to a fourth adder 122 included in the second adder 114.

[0023] Here, by using the head-related transfer function coefficients prepared in advance, the operator can perform the three-dimensional localization processing without performing complicated operations related to the localization processing. However, the operator may perform the setting operation of various parameters related to the localization processing, so that the three-dimensional localization processing according to the purpose may be performed appropriately.

[0024] In FIG. 1, two third stereo signals (four signals in total), a third stereo signal for the right channel generated from the right channel signal and a third stereo signal for the left channel generated from the left channel signal, are output from the localization processing unit 112 to the second adder 114. However, the third stereo signal for the right channel and the third stereo signal for the left channel are signals that are added between the right channels and between the left channels in a second adder described later. Therefore, the localization processing unit 112 may internally mix the right channel signals and the left channel signals of the two generated third stereo signals, respectively, and output the mixed stereo signal as one third stereo mixed signal. In this case, the mixing process of the localization processing unit 112 is regarded as a part (fifth adder 602) of the addition process of a fourth adder (part of the second adder) described later.

[0025] Specifically, the localization processing unit 112 mixes the right channel signal of the generated third stereo signal related to the right channel with the right channel signal of the generated third stereo signal related to the left channel to generate a single right channel signal. Similarly, the localization processing unit 112 mixes the left channel signal of the generated third stereo signal related to the right channel with the left channel signal of the generated third stereo signal related to the left channel to generate a single left channel signal. The localization processing unit 112 outputs the single pair of stereo signals to the fourth adder 122 as a third stereo mixed signal (see FIG. 6).

[0026] The second adder 114 mixes the first stereo signal of one or more channels whose second parameter specifies in-head localization among the multiple channels with two third stereo signals to generate a fourth stereo signal. Specifically, for example, as shown in FIG. 1, the second adder 114 includes a third adder 120 and a fourth adder 122. The third adder 120 and the fourth adder 122 may be any bus such as a mixing bus, a stereo bus, or a matrix bus, or may be an adder that is not a bus. The third adder 120 mixes the first stereo signal of one or more channels whose second parameter specifies in-head localization among the multiple channels with one or more channels to generate a fifth stereo signal. In the above example, the third adder 120 mixes the first stereo signal output by the third input channel 106C and the fifth input channel 106E to generate a fifth stereo signal. The fourth adder 122 mixes the two third stereo signals obtained from the localization processing unit 112 and the one fifth stereo signal obtained from the third adder 120 to generate one fourth stereo signal. The second adder 114 outputs the generated fourth stereo signal to the output circuit 116.

[0027] It is preferable that the mixing ratio when the first stereo signal and the second third stereo signal are mixed is a preset ratio. For example, the fourth adder 122 mixes the third stereo signal and the fifth stereo signal at a mixing ratio of 1:1. By using a predetermined mixing ratio, the operation of the operator is reduced. It is also possible for the mixing ratio to be other ratios rather than being limited to 1:1, and it may be possible for the ratio to be appropriately set depending on the application.

[0028] In addition, when the localization processing unit 112 includes the fifth adder 602, the third stereo mixed signal is supplied from the localization processing unit 112 to the sixth adder 604. In this case, the second adder 114 operates as the sixth adder 604 that mixes the first stereo signal of one or more channels whose second parameter among the multiple channels specifies in-head localization with the third stereo mixed signal to generate a fourth stereo signal. The second adder 114 includes the sixth adder 604 and the fifth adder 602 of the localization processing unit 112.

[0029] The output circuit 116 outputs a fourth stereo signal. Specifically, the output circuit 116 performs various signal processing such as level adjustment and frequency characteristic adjustment on the fourth stereo signal output from the fourth adder 122 as necessary, and outputs the signal to the transmitter 118. The transmitter 118 wirelessly transmits the fourth stereo signal output from the output circuit 116 to the in-ear monitor 102. A receiver provided in the in-ear monitor 102 receives the fourth stereo signal transmitted by the transmitter 118. The in-ear monitor 102 emits sound based on the received fourth stereo signal. This allows a performer (such as a vocalist) wearing the in-ear monitor 102 to hear sounds in which some of the acoustic signals input to the input channels 106 are localized outside the head, and sounds in which the acoustic signals input to the remaining input channels 106 are localized inside the head.

[0030] 1 shows only one transmitter 118 and one in-ear monitor 102, multiple transmitters 118 and multiple in-ear monitors 102 may be provided depending on the number of performers. Also, multiple signals mixed for the audience may be output directly from output circuit 116 to speakers arranged facing the audience at a live venue.

[0031] Furthermore, when there are multiple in-ear monitors, the first adder 110 and the second adder 114 may be provided for each output destination (for each in-ear monitor 102, or for each group including several in-ear monitors), and a process of generating a different fourth stereo signal according to the output destination may be performed. Specifically, the user interface 104 may collectively switch various parameters controlled by each control of the channel strip 202 according to a mode indicating an output destination selected by an operator. Modes that can be selected include, for example, a mode for a guitar player, a mode for a vocalist, a mode for a drummer, etc.

[0032] For example, when the guitar player mode is selected, the fourth stereo signal generated through the first adder 110 and the second adder 114 associated with the guitar player mode is output to the guitar player's in-ear monitor 102. When the vocal mode is selected, the fourth stereo signal generated through the first adder 110 and the second adder 114 associated with the vocal mode is output to the vocal in-ear monitor 102.

[0033] The audio mixer described above may be realized by hardware or software on a personal computer. By using such an audio mixer, a monitor system 100 can be constructed in which an operator can easily specify the localization position of each channel in a three-dimensional space.

[0034] Next, a method for processing an acoustic signal according to the present disclosure will be described. Note that a case will be described in which acoustic signals input to the first input channel 106A to the fifth input channel 106E are localized at positions as shown in FIG.

[0035] First, the user interface 104 receives a first parameter and a second parameter. Specifically, the operator operates the first control 104A of the first input channel 106A so that the sound of the audio signal of the first input channel 106A is localized in the center. Similarly, the operator operates the first control 104A of the second input channel 106B and the third input channel 106C so that the audio signals of the second input channel 106B and the third input channel 106C are localized on the left side. The operator operates the first control 104A of the fourth input channel 106D and the fifth input channel 106E so that the audio signals of the fourth input channel 106D and the fifth input channel 106E are localized on the right side.

[0036] The operator also performs an operation to specify out-of-head localization for the second controls 104B of the first input channel 106A, the second input channel 106B, and the fourth input channel 106D. Similarly, the operator performs an operation to specify in-head localization for the second controls 104B of the third input channel 106C and the fifth input channel 106E. Through the above operations, the user interface 104 supplies the first parameter and the second parameter for each input channel 106.

[0037] As a result, each input channel 106 pans the input acoustic signal according to the corresponding first parameter to generate a first stereo signal. Then, the first stereo signals generated by the first input channel 106A, the second input channel 106B, and the fourth input channel 106D are output to the first adder 110. The first stereo signals generated by the third input channel 106C and the fifth input channel 106E are output to the second adder 114.

[0038] The first adder 110 mixes the first stereo signals output from the first input channel 106A, the second input channel 106B, and the fourth input channel 106D to generate a second stereo signal. The generated second stereo signal is output to the mix channel 108.

[0039] The third adder 120 mixes the first stereo signal output by the third input channel 106C and the fifth input channel 106E to generate a fifth stereo signal.

[0040] The second stereo signal that has been subjected to various signal processing as necessary in the mix channel 108 is input to the localization processing unit 112. The localization processing unit 112 performs the above-mentioned out-of-head localization processing on the second stereo signal to generate a second third stereo signal.

[0041] Here, the second stereo signal is a signal obtained by mixing the first stereo signals generated by the first input channel 106A, the second input channel 106B, and the fourth input channel 106D. There is no need to specify the localization positions individually for the first input channel 106A, the second input channel 106B, and the fourth input channel 106D, and this reduces the amount of work required by the operator.

[0042] The fourth adder 122 mixes the third stereo signal obtained from the localization processing unit 112 and the fifth stereo signal obtained from the third adder 120 to generate a fourth stereo signal.

[0043] The output circuit 116 performs various signal processing as necessary on the fourth stereo signal output from the fourth adder 122, and then outputs the signal to the transmitter 118. The transmitter 118 wirelessly transmits the fourth stereo signal to the in-ear monitor 102, so that the performer (vocalist) wearing the in-ear monitor 102 can hear sounds in which some of the acoustic signals of the input channels 106 are localized outside the head, and the remaining acoustic signals of the input channels 106 are localized inside the head.

[0044] The present audio signal processing method may be applied to various monitoring applications, such as monitoring a singer in karaoke, monitoring each participant in a remote conference system, etc. The audio mixer is not limited to dedicated mixing hardware, and may be an audio workstation (DAW) application running on a computer, or a mixing instance deployed on the cloud.

[0045] According to the present disclosure, an operator can control the localization position in a three-dimensional space using only two parameters, a parameter indicating whether the position is outside or inside the head and a parameter indicating the left-right position. Therefore, the operator can easily grasp the localization position by looking at the two parameters of each channel. In addition, there is no need to set the outside-head localization position for each of the multiple acoustic signals, and the operation is easy for a normal operator who is accustomed to localization control operations in left-right localization.

[0046] [Second embodiment] 5 is a block diagram of a monitor system including an audio mixer according to the second embodiment. Description of the same configuration as the first embodiment will be omitted. The first embodiment differs in that the second adder 114 includes a third adder 120 and a fourth adder 122, but the second embodiment differs in that the second adder 114 is a single adder (bus).

[0047] The second adder 114 mixes the first stereo signal of one or more channels, the second parameter of which specifies in-head localization, with the two third stereo signals acquired from the localization processing unit 112 to generate a fourth stereo signal. The second adder 114 transmits the generated fourth stereo signal to the second mix channel 108. The first mix channel 108A and the second mix channel 108B perform various signal processing on the input stereo signal, similar to the mix channel 108 in the first embodiment. In the second embodiment, similar to the first embodiment, it is possible to perform out-of-head localization processing on the sound signals of some of the input channels 106, and mix both without performing the localization processing on the sound signals of the remaining input channels 106. Note that, similar to the first embodiment, the first mix channel 108A and the second mix channel 108B may be omitted.

[0048] As in the first embodiment, the second adder 114 may be any bus, such as a mixing bus, a stereo bus, a matrix bus, etc. In the first embodiment, two buses are required as the second adder 114, but in the second embodiment, only one bus is used as the second adder 114. Therefore, the number of buses used in the audio mixer can be reduced.

[0049] 5 includes the fifth adder 602, the third stereo mixed signal is supplied from the localization processing unit 112 to the sixth adder 604. In this case, the second adder 114 operates as the sixth adder 604 that mixes the first stereo signal of one or more channels for which the second parameter of the multiple channels specifies in-head localization with the third stereo mixed signal to generate a fourth stereo signal. The second adder 114 includes the sixth adder 604 and the fifth adder 602 of the localization processing unit 112.

[0050] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. The above-mentioned configuration of the audio mixer and the method of processing the audio signal are merely examples, and the present invention is not limited to these. The configurations shown in the above-mentioned embodiment may be replaced with a configuration that is substantially the same as the configuration shown in the above-mentioned embodiment, that has the same effect, or that achieves the same purpose. [Explanation of symbols]

[0051] 100 monitor system, 102 in-ear monitor, 104 user interface, 104A first control, 104B second control, 104C third control, 106 input channel, 108 mix channel, 110 first adder, 112 localization processing section, 114 second adder, 116 output circuit, 118 transmitter, 120 third adder, 122 fourth adder, 202 channel strip, 302 compressor, 304 equalizer, 306 fader, 308 panner, 602 fifth adder, 604 sixth adder.

Claims

1. a user interface that supplies, for each of the multiple channels, a first parameter indicating a position in a left-right direction and a second parameter specifying at least one of an intra-head localization and an extra-head localization in response to an operation by an operator; a panner for panning the sound signal of each of the channels in accordance with the first parameter to generate a plurality of first stereo signals of the plurality of channels; a first adder for mixing the first stereo signals of one or more channels among the plurality of channels, the second parameter of which specifies an out-of-head localization, to generate a second stereo signal; a localization processing unit that performs three-dimensional localization processing on the second stereo signal to generate a second third stereo signal; a second adder for mixing the first stereo signal and the second third stereo signal of one or more channels among the plurality of channels for which the second parameter specifies in-head localization to generate a fourth stereo signal; an output circuit for outputting the fourth stereo signal; An audio mixer comprising:

2. The second adder is a third adder for mixing the first stereo signals of one or more channels among the plurality of channels, the second parameter of which specifies an in-head localization, to generate a fifth stereo signal; a fourth adder for mixing the second third stereo signal and the fifth stereo signal to generate the fourth stereo signal; Equipped with 2. The audio mixer of claim 1.

3. 3. The audio mixer according to claim 1, wherein the second parameter specifies, for each channel, whether the first stereo signal is to be input to the first adder or the second adder.

4. 3. The audio mixer according to claim 1, wherein the second parameter specifies, for each channel, a level balance between the first stereo signal and the second adder when the first stereo signal is input to the first adder and the second adder.

5. 5. The audio mixer according to claim 1, wherein a mixing ratio when the first stereo signal and one or more of the third stereo signals are mixed is a preset ratio.

6. 6. The audio mixer according to claim 1, wherein the localization processing unit performs three-dimensional localization processing on each of a right channel signal and a left channel signal included in the second stereo signal to generate two third stereo signals.

7. The second adder is a fifth adder for mixing the two third stereo signals to generate one third stereo mixed signal; a sixth adder for mixing the first stereo signal of one or more channels, the second parameter of which designates an in-head localization, with the third stereo mixed signal to generate the fourth stereo signal; Equipped with 7. The audio mixer of claim 6.

8. supplying, for each of the plurality of channels, a first parameter indicating a position in a left-right direction and a second parameter specifying at least one of an intra-head localization and an extra-head localization in response to an operation by an operator; panning the sound signal of each of the channels in accordance with the first parameter to generate a plurality of first stereo signals of the plurality of channels; mixing the first stereo signals of one or more channels of the plurality of channels, the second parameter of which specifies an out-of-head localization, to generate a second stereo signal; performing a three-dimensional localization process on the second stereo signal to generate a second third stereo signal; mixing the first stereo signal and the second third stereo signal of one or more channels of the plurality of channels, the second parameter of which specifies an in-head localization, to generate a fourth stereo signal; outputting the fourth stereo signal; A method for processing an acoustic signal.

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