JP6550756B2 - Audio signal processor - Google Patents

Description

  The present invention relates to an audio signal processing apparatus that performs various processes on an audio signal (see, for example, Patent Document 1).

  BACKGROUND ART Conventionally, a sound field support device that forms a desired sound field in a listening environment is known. The sound field support apparatus synthesizes audio signals of a plurality of channels, and convolutes a predetermined parameter into the synthesized audio signal to generate a pseudo reflection sound (sound field sound effect).

  On the other hand, in recent years, a method of sound image localization by object information added to contents has become widespread. The object information includes information indicating the position of each object (sound source).

JP 2001-186599 A

  For example, in the case where the content is recorded in a small concert hall, when setting the application of the sound effect of the large concert hall in the listening environment, the indirect sound spreads but the position of the direct sound (each sound source) does not change.

  Then, this invention aims at providing the audio signal processing apparatus which provides an appropriate sound image position.

  An audio signal processing apparatus according to the present invention comprises audio signal input means for inputting an audio signal relating to content, acquisition means for acquiring position information of an object contained in the content, and sound image localization of the object based on the position information. A sound image localization processing unit that performs the sound processing, a sound field providing unit that performs processing to apply a sound field effect to the audio signal, a reception unit that receives a change instruction of the listening environment, and a change instruction of the listening environment received by the reception unit And a control unit that controls the sound image position of the sound image localization processing unit.

  As described above, the audio signal processing device of the present invention rearranges the sound image positions using the position information included in the object information. For example, when specification of the acoustic space of the large concert hall is received as a change instruction of the listening environment, each object is located at a position corresponding to the scale of the large concert hall by repositioning the position of the object far from the listening position. Relocate Also, the audio signal processing device rearranges the position of each object according to the listening position designated as the change instruction of the listening environment. For example, when the listening position is specified at a position immediately in front of the stage, the position of the object is rearranged near the listening position, and when the listening position is specified at a position far from the stage, the position of the object is set. Relocate to a position far from the listening position. Therefore, not only the sound field environment of the selected acoustic space, but also the position of the sound source corresponding to the direct sound can be brought close to the actual acoustic space.

  The audio signal processing apparatus further includes storage means for storing, for each listening position, sound field effect information for applying a sound field effect to the audio signal, and the control unit is configured to receive the listening position received by the receiving unit. Preferably, the sound field effect information is read out from the storage means according to the setting, and is set in the sound field application unit.

  Thereby, for example, a sound field at a position immediately in front of the stage, a sound field at a position far from the stage, and the like can be reproduced.

  The control unit can also read out a plurality of sound field effect information stored in the storage unit and interpolate the sound field effect information of the corresponding listening position from the read sound field effect information.

  For example, the direct sound increases at a position immediately in front of the stage, and the indirect sound increases at a position far from the stage. Therefore, for example, when the listening position at the center of the hall is selected, the sound field effect information corresponding to the measurement result immediately before the stage and the sound field effect information corresponding to the measurement result at a position far from the stage By averaging, the sound field effect information corresponding to the listening position at the center of the hole can also be interpolated.

It has a direction detection unit that detects the direction the listener is facing,
The audio signal processing apparatus according to any one of claims 1 to 4, wherein the control unit controls the sound image position of the sound image localization processing unit according to the direction in which the listener is facing detected by the direction detection unit. .

  According to the present invention, an appropriate sound image position can be provided.

It is a schematic diagram of listening environment. It is a block diagram of the audio signal processing device concerning a 1st embodiment. It is the block diagram which showed the functional structure of DSP and CPU. It is a block diagram which shows the functional structure of DSP which concerns on the modification of 1st Embodiment. It is a block diagram which shows the functional structure of DSP which concerns on the modification of 2nd Embodiment. It is a block diagram which shows the functional structure of an analysis part. It is a block diagram which shows the functional structure of the audio signal processing part 14 which concerns on the modification 1 of 1st Embodiment (or 2nd Embodiment). It is a schematic diagram of the listening environment which concerns on 3rd Embodiment. It is a block diagram of the audio signal processing apparatus in 3rd Embodiment.

First Embodiment
FIG. 1 is a schematic diagram of a listening environment in the first embodiment, and FIG. 2 is a block diagram of an audio signal processing apparatus 1 in the first embodiment. In the present embodiment, as an example, a listening environment in which the center position is the listening position in a square room in plan view is shown. A plurality of speakers (in this example, five speakers 21L, speakers 21R, speakers 21C, speakers 21SL, and speakers 21SR) are installed around the listening position. The speaker 21L is the front left side of the listening position, the speaker 21R is the front right side of the listening position, the speaker 21C is the front center of the listening position, the speaker 21SL is the rear left side of the listening position, and the speaker 21SR is the rear right side of the listening position. is set up. The speaker 21L, the speaker 21R, the speaker 21C, the speaker 21SL, and the speaker 21SR are each connected to the audio signal processing device 1.

  The audio signal processing apparatus 1 includes an input unit 11, a decoder 12, a renderer 13, an audio signal processing unit 14, a D / A converter 15, an amplifier (AMP) 16, a CPU 17, a ROM 18 and a RAM 19.

  The CPU 17 reads an operation program (firmware) stored in the ROM 18 into the RAM 19 and centrally controls the audio signal processing apparatus 1.

  The input unit 11 has an interface such as HDMI (registered trademark). The input unit 11 receives content data from a player or the like and outputs the content data to the decoder 12.

  The decoder 12 is composed of a DSP, for example, and decodes content data and extracts an audio signal. In the present embodiment, audio signals are all described as digital audio signals unless otherwise specified.

  The decoder 12 extracts object information when the input content data corresponds to the object-based method. The object-based method stores an object (sound source) included in content as an independent audio signal. In the object-based method, sound image localization (in object units) is performed by distributing the audio signal of the object to the audio signal of each channel by the renderer 13 in the subsequent stage. Therefore, the object information includes information such as position information and level of each object.

  The renderer 13 is made of, for example, a DSP, and performs sound image localization processing based on the position information of each object included in the object information. That is, the renderer 13 distributes the audio signal of each object output from the decoder 12 to the audio signal of each channel with a predetermined gain so that the sound image is localized at the position corresponding to the position information of each object. Thus, a channel based audio signal is generated. The generated audio signal of each channel is output to the audio signal processing unit 14.

  The audio signal processing unit 14 is formed of, for example, a DSP, and performs a process of applying a predetermined sound field effect to the input audio signal of each channel according to the setting of the CPU 17.

  The sound field effect is composed of, for example, a pseudo reflected sound generated from an input audio signal. The generated pseudo reflected sound is added to the original audio signal and output.

  FIG. 3 is a block diagram showing the functional configuration of the audio signal processing unit 14 and the CPU 17. The audio signal processing unit 14 functionally includes an addition processing unit 141, a sound effect sound generation unit 142, and an addition processing unit 143.

  The addition processing unit 141 combines the audio signals of the respective channels with a predetermined gain and mixes them down into a monaural signal. The gain of each channel is set by the control unit 171 in the CPU 17. Generally, when the sound source is speech such as speech, it is preferable to suppress the sound field effect, so the gain of the front channel or surround channel often containing many components such as music is high, and the component such as speech is The center channel gain, which is often included, is set low.

  The sound effect sound generation unit 142 is, for example, an FIR filter, and generates pseudo-reflected sound by convolving a parameter (filter coefficient) indicating a predetermined impulse response with the input audio signal. Further, the sound effect sound generation unit 142 performs processing of distributing the generated pseudo reflection sound to each channel. The filter coefficient and the distribution ratio are set by the control unit 171 in the CPU 17.

  The CPU 17 functionally includes a control unit 171 and an object information acquisition unit 172. The control unit 171 sets the filter coefficient, the distribution ratio to each channel, and the like in the sound effect sound generation unit 142 based on the sound effect information stored in the ROM 18.

  The sound field effect information includes information indicating an impulse response of a reflected sound group generated in a certain acoustic space and a sound source position of the reflected sound group. For example, when an audio signal is supplied to the speaker 21L and the speaker 21SL with a predetermined delay amount and a predetermined gain ratio (for example, 1: 1), pseudo reflected sound can be generated on the left side of the listening position. The sound field effect information includes, for example, settings for a presence sound field that produces a sound field on the upper front side and settings for a surround sound field that produces a sound field on the surround side. The sound field effect information to be selected may be fixed to one in the audio signal processing device 1, but the specification of the sound space desired by the user, such as a movie theater or a concert hall, is received and corresponds to the received sound space. Sound field effect information to be selected may be selected.

  As described above, a sound effect sound is generated and added to each channel in the addition processing unit 141. Thereafter, the audio signal of each channel is converted into an analog signal by the D / A converter 15, amplified by the amplifier 16, and then output to each speaker. Thereby, a sound field imitating a predetermined acoustic space such as a concert hall is formed around the listening position.

  Then, in the audio signal processing device 1 of the present embodiment, the object information acquisition unit 172 acquires the object information extracted by the decoder 12, and forms an optimal sound field for each object. The control unit 171 sets the gain of each channel of the addition processing unit 141 based on the position information included in the object information acquired by the object information acquisition unit 172. Thus, the control unit 171 controls the gain of each channel in the sound field effect sound generation unit 142.

  For example, if there is an object in front of the listening position at time t = 1, the object moves near the listening position at time t = 2, and moves behind the listening position at time t = 3 Assume. At time t = 1, the control unit 171 sets the gain of the front channel to the maximum, and sets the gain of the surround channel of the addition processing unit 141 to the minimum. At time t = 2, the control unit 171 sets the gain of the front channel of the addition processing unit 141 and the gain of the surround channel to the same degree. Thereafter, at time t = 3, the control unit 171 sets the surround channel gain of the addition processing unit 141 to the maximum, and sets the front channel gain to the minimum.

  As described above, the audio signal processing device 1 can dynamically change the formed sound field by dynamically changing the gain of each channel of the addition processing unit 141 in response to the moving object. . Therefore, the listener can obtain a more effective sound field effect.

  In the present embodiment, five speakers 21L, 21R, 21C, 21SL, and 21SR are provided to facilitate the description, and an example of processing five channels of audio signals is shown. The number of channels and the number of channels are not limited to this example. In practice, in order to realize three-dimensional sound image localization and sound field effects, it is preferable to install a larger number of speakers at different heights.

  In the above example, the audio signal of each channel is synthesized with a gain based on the acquired position information, and a parameter (filter coefficient) indicating a predetermined impulse response is convoluted to generate a pseudo-reflected sound. However, a process of adding a sound field effect may be performed by convolving an individual filter coefficient with the audio signal of each channel. In this case, the ROM 18 stores a plurality of filter coefficients corresponding to the position of the object, and the control unit 171 reads the corresponding filter coefficients from the ROM 18 based on the acquired position information to generate sound field sound effects. Set in section 142. In addition, the control unit 171 synthesizes the audio signal of each channel with the gain based on the acquired position information, reads the corresponding filter coefficient from the ROM 18 based on the acquired position information, and outputs it to the sound field effect sound generation unit 142 You may perform the process to set.

Second Embodiment
Next, FIG. 4 is a block diagram showing a configuration of an audio signal processing device 1B according to the second embodiment. The same components as those of the audio signal processing apparatus 1 according to the first embodiment shown in FIG. The listening environment according to the second embodiment is the same as the listening environment according to the first embodiment shown in FIG.

  The audio signal processing unit 14 in the audio signal processing device 1B has the function of the analysis unit 91 in addition to the functions shown in FIG. Actually, the analysis unit 91 is realized as another hardware (DSP), but in the second embodiment, it is assumed to be realized as a function of the audio signal processing unit 14 for the sake of explanation. The analysis unit 91 can also be realized by software by the CPU 17.

  The analysis unit 91 extracts the object information included in the content by analyzing the audio signal of each channel. That is, in the audio signal processing device 1B of the second embodiment, when the CPU 17 does not acquire (cannot acquire) the object information from the decoder 12, the object information is estimated by analyzing the audio signal of each channel.

  FIG. 5 is a block diagram showing a functional configuration of the analysis unit 91. As shown in FIG. The analysis unit 91 includes a band division unit 911 and a calculation unit 912. The band division unit 911 divides the audio signal of each channel into predetermined frequency bands. In this example, an example of dividing into three bands of low band (LPF), middle band (BPF), and high band (HPF) is shown. However, the bandwidth to be divided is not limited to three. The band-divided audio signal of each channel is input to the calculation unit 912.

  The calculation unit 912 calculates the cross-correlation between channels in each divided band. The calculated cross-correlation is input to the object information acquisition unit 172 of the CPU 17. The calculating unit 912 also functions as a level detecting unit that detects the level of the audio signal of each channel. The level information of the audio signal of each channel is also input to the object information acquisition unit 172.

  The object information acquisition unit 172 estimates the position of the object based on the input correlation value and the level information of the audio signal of each channel.

  For example, as shown in FIG. 6A, the correlation value between the L channel and the SL channel in the low band (Low) is high (above a predetermined threshold), and as shown in FIG. When the L channel level and the SL channel level in (1) are high (above a predetermined threshold), it is assumed that an object is present between the speaker 21L and the speaker 21SL as shown in FIG. 6 (C).

  Also, in the high band (High), there is no channel with high correlation, but a high level audio signal is input in the mid band (Mid) C channel. Therefore, as shown in FIG. 6C, it is assumed that an object is present near the speaker 21C.

  In this case, the control unit 171 sets the gain of the L channel and the gain of the SL channel to the same degree (0.5: 0.5) for the gains set in the addition processing unit 141 in FIG. Set the gain to maximum (1). The gain of other channels is set to the minimum. As a result, a sound effect sound with an optimum contribution rate set in accordance with the position of each object is generated.

  However, since the high level signal in the C channel may be related to voice such as speech, it is preferable that the control unit 171 set the gain by also referring to information on the type of the object. Information regarding the type of object will be described later.

  At this time, it is preferable that the control unit 171 reads out the sound field effect information set for each band from the ROM 18 and sets an individual parameter (filter coefficient) in the sound field sound generation unit 142 for each band. For example, the reverberation time is short for the low band, and the reverberation time is long for the high band.

  Note that the more the number of channels, the more accurately the position of the object can be estimated. In this example, all the speakers are arranged at the same height, and an example of calculating the correlation value of the audio signal of five channels is shown, but in reality, in order to realize three-dimensional sound image localization and sound field effect The position of the sound source can be almost uniquely determined in order to install more speakers at different heights and calculate the correlation value between the more channels.

  In this embodiment, the audio signal of each channel is divided for each band to obtain the position information of the object for each band. However, the configuration for acquiring the position information of the object for each band is as follows. This is not an essential configuration in the present invention.

(Modification 1)
Next, FIG. 7 is a block diagram showing a functional configuration of the audio signal processing unit 14 according to the first modification of the first embodiment (or the second embodiment). The audio signal processing unit 14 according to the first modification includes an addition processing unit 141A, a first sound effect sound generation unit 142A, an addition processing unit 141B, a second sound effect sound generation unit 142B, and an addition processing unit 143. There is. Although the addition processing unit 141B and the second sound field effect sound generation unit 142B are actually configured as separate hardware (DSP), in this example, the functions of the audio signal processing unit 14 are described for the sake of explanation. It shall be realized as

  The addition processing unit 141A combines the audio signals of the respective channels with a predetermined gain and mixes them down to a monaural signal. The gain of each channel is fixed. For example, as described above, the gain of the front channel and the surround channel is set high, and the gain of the center channel is set low.

  The first sound field effect sound generation unit 142A generates a pseudo-reflected sound by convolving a parameter (filter coefficient) indicating a predetermined impulse response into the input audio signal. The first sound field effect sound generation unit 142A performs a process of distributing the generated pseudo reflected sound to each channel. The filter coefficient and the distribution ratio are set by the control unit 171. As in the example of FIG. 3, it is possible to receive designation of an acoustic space desired by the user, such as a movie theater or a concert hall, and select sound field effect information corresponding to the received acoustic space.

  On the other hand, the control unit 171 sets the gain of each channel of the addition processing unit 141B based on the position information included in the object information acquired by the object information acquisition unit 172. Thus, the control unit 171 controls the gain of each channel in the second sound field effect sound generation unit 142B.

  The sound field effect sound generated by the first sound field sound effect generator 142A and the sound field sound effect generated by the second sound field sound effect generator 142B are audio of each channel in the addition processor 143. It is added to the signal.

  Therefore, while the audio signal processing unit 14 according to the modification generates the sound effect sound with the contribution ratio of each channel fixed as in the prior art, the sound in which the optimum contribution ratio according to the position of each object is set A field sound effect is generated.

(Modification 2)
Next, an audio signal processing device according to Modification 2 of the first embodiment (or the second embodiment) will be described. The audio signal processing unit 14 and the CPU 17 according to the second modification have the same functional configuration as the configuration shown in FIG. 3 (or the configuration shown in FIG. 7). However, the object information acquisition unit 172 according to the second modification acquires, as object information, information indicating the type of object in addition to the position information.

  The information indicating the type of object is, for example, information indicating the type of sound source such as a speech, a musical instrument, a sound effect, or the like. When the information indicating the type of the object is included in the content data, the decoder 12 extracts the information, but the information can also be estimated by the calculation unit 912 in the analysis unit 91.

  For example, the band division unit 911 in the analysis unit 91 extracts the bands of the first formant (200 Hz to 500 Hz) and the second formant (2 kHz to 3 kHz) from the input audio signal. If the input signal component contains a large amount of components related to serif or only the component related to serif, the components of the first formant and the second formant are contained more than in the other bands.

  Therefore, when the level of the component of the first formant or the second formant is higher than the average level of the entire frequency band, the object information acquisition unit 172 determines that the type of the object is a serif.

  The control unit 171 sets the gain of the addition processing unit 141 (or the addition processing unit 141B) based on the type of object. For example, as shown in FIG. 6C, when there is an object on the left side of the listening position and the type of the object is a speech, the gains of the L channel and the SL channel are set low. Further, as shown in FIG. 6C, when the object is present in front of the listening position and the type of the object is a speech, the gain of the C channel is set low.

(Modification 3)
As a modification 3 of the second embodiment, the audio signal processing apparatus 1B can display the position of an object on a display unit (not shown) using the estimated position information of the object. Thereby, the user can visually grasp the movement of the sound source. In the case of content such as a movie, there are many cases where the display unit has already displayed a video corresponding to a sound source, but the displayed video is a subjective visual field. Therefore, the audio signal processing device 1B can also display the position of the object as, for example, an overhead view centering on its own position.

Third Embodiment
Next, FIGS. 8A and 8B are schematic views of a listening environment according to the third embodiment, and FIG. 9 is a block diagram of an audio signal processing device 1C according to the third embodiment. The audio signal processing device 1C according to the third embodiment has the same hardware configuration as the audio signal processing device 1 shown in FIG. 2, but further includes a user interface (I / F) 81.

  The user I / F 81 is an interface for receiving user's operation, and is formed of, for example, a switch, a touch panel, or a remote control provided in a housing of the audio signal processing apparatus. The user designates a desired acoustic space as a listening environment change instruction via the user I / F 81.

  The control unit 171 of the CPU 17 receives the specification of the sound space, and reads the sound field effect information corresponding to the specified sound space from the ROM 18. Then, the control unit 171 sets, in the audio signal processing unit 14, a filter coefficient based on the sound field effect information, a distribution ratio to each channel, and the like.

  Furthermore, the control unit 171 converts the position information of the object acquired by the object information acquisition unit 172 into a position corresponding to the read sound field effect information, and outputs the converted position information to the renderer 13 to obtain an object. Relocate

  That is, for example, when the control unit 171 receives specification of the acoustic space of the large concert hall, the control unit 171 rearranges the position of the object at a position far from the listening position to obtain each object at a position corresponding to the scale of the large concert hall. Relocate The renderer 13 performs sound image localization processing based on the position information input from the control unit 171.

  For example, as illustrated in FIG. 8A, when the object 51R is disposed on the front right side of the listening position and the object 51L is disposed on the front left side of the listening position, the control unit 171 illustrated in FIG. As shown in FIG. 5, when the specification of the acoustic space of the large concert hall is received, the object 51R and the object 51L are rearranged at a position away from the listening position. Thereby, not only the sound field environment of the selected acoustic space but also the position of the sound source corresponding to the direct sound can be brought close to the actual acoustic space.

  The control unit 171 also converts the movement of the object into a movement amount corresponding to the selected acoustic space. For example, in a theater or the like, a performer utters a speech while moving dynamically. For example, when the specification of the acoustic space of the large hole is received, the control unit 171 increases the movement amount of the object extracted by the decoder 12 and rearranges the position of the object corresponding to the performer. As a result, it is possible to give a sense of presence as if the performer is performing at the place.

  Further, the user I / F 81 can also accept the designation of the listening position as a listening environment change instruction. For example, after selecting the acoustic space of the large hall, the user further positions in front of the stage in the hall, the second floor (position obliquely overlooking the stage), a position far from the stage near the exit, etc. Select the listening position of.

  The control unit 171 rearranges each object according to the designated listening position. For example, when the listening position is specified at a position immediately in front of the stage, the position of the object is rearranged near the listening position, and when the listening position is specified at a position far from the stage, the position of the object is set. Relocate to a position far from the listening position. Also, for example, when the position of the second floor is designated as a listening position (a position looking down on the stage from diagonally above), the position of the object is rearranged at an oblique position as viewed from the listener.

  Further, when the designation of the listening position is received, it is preferable to measure the actual sound field (the arrival timing and direction of the indirect sound) at each position and store it in the ROM 18 as sound field effect information. The control unit 171 reads from the ROM 18 sound field effect information corresponding to the designated listening position. Thereby, a sound field at a position immediately in front of the stage, a sound field at a position far from the stage, and the like can be reproduced.

  The sound field effect information need not be measured at all positions in the actual acoustic space. For example, the direct sound increases at a position immediately in front of the stage, and the indirect sound increases at a position far from the stage. Therefore, for example, when the listening position at the center of the hall is selected, the sound field effect information corresponding to the measurement result immediately before the stage and the sound field effect information corresponding to the measurement result at a position far from the stage By averaging, the sound field effect information corresponding to the listening position at the center of the hole can also be interpolated.

(Application example)
The audio signal processing device 1B according to the application example acquires information on the direction in which the user is facing, using a gyro sensor or the like provided on a terminal worn by the user. The control unit 171 rearranges each object according to the direction in which the user is facing.

  For example, when the listener points to the right, the control unit 171 rearranges the position of the object at the position on the left as viewed from the listener.

  Further, the ROM 18 of the audio signal processing device 1B according to the application example stores sound field effect information for each direction. The control unit 171 reads out the sound field effect information from the ROM 18 in accordance with the direction in which the listener is facing, and sets the information in the audio signal processing unit 14. Thus, the user can obtain a sense of realism as if he were at the place.

1, 1B, 1C ... audio signal processing apparatus 11 ... input unit 12 ... decoder 13 ... renderer 14 ... audio signal processing unit 15 ... D / A converter 17 ... CPU
18: ROM
19 ... RAM
21C, 21L, 21R, 21SL, 21SR ... speaker 51L, 51R ... object 91 ... analysis unit 141, 141A, 141B ... addition processing unit 142 ... sound field effect sound generating unit 142A ... first sound field effect sound generating unit 142B ... first 2 sound field effect sound generation unit 143 ... addition processing unit 171 ... control unit 172 ... object information acquisition unit 911 ... band division unit 912 ... correlation calculation unit

Claims (6)

Audio signal input means for inputting an audio signal related to the content;
Acquisition means for acquiring position information of an object included in the content;
A sound image localization processing unit that performs sound image localization of the object based on the position information;
A sound field application unit that performs processing for applying a sound field effect to the audio signal;
A reception unit that receives an instruction to change the listening environment;
A control unit that controls a sound image position of the sound image localization processing unit by adjusting a movement amount of the object in response to a change instruction of a listening environment received by the reception unit;
An audio signal processing apparatus comprising: Storage means for storing, for each listening position, sound field effect information for applying a sound field effect to the audio signal;
The reception unit receives a setting of a listening position as an instruction to change the listening environment,
The audio signal processing apparatus according to claim 1, wherein the control unit reads the sound field effect information from the storage unit according to the setting of the listening position received by the reception unit, and sets the read information on the sound field application unit.   The audio signal according to claim 2, wherein the control unit reads out a plurality of sound field effect information stored in the storage means, and interpolates sound field effect information of a corresponding listening position from each read sound field effect information. Processing unit. It has a direction detection unit that detects the direction the listener is facing,
The audio signal processing apparatus according to any one of claims 1 to 3, wherein the control unit controls the sound image position of the sound image localization processing unit according to the direction in which the listener is facing detected by the direction detection unit. .   The audio signal is a multi-channel audio signal,
  The audio signal processing apparatus according to any one of claims 1 to 4, wherein the sound image localization processing unit mixes down the audio signal to a monaural signal.   The position information is an object signal stored in the content as an independent audio signal for each of the objects,
  The audio signal processing apparatus according to any one of claims 1 to 5, wherein the acquisition unit acquires the position information included in the object signal.

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