Audio device, audio control method

Abstract

It is possible to form a high-quality sound image with a voice signal having the same phase and the same amplitude component. 【Solution means】The audio device of the embodiment is an audio device that performs processing for outputting voice from a plurality of speakers, and from each of a left input voice signal corresponding to a left channel and a right input voice signal corresponding to a right channel, a first separation unit that separates a correlation component used to form a sound image localization, a second separation unit that separates a voice signal component that becomes a same-phase and same-amplitude component from the voice signal separated by the first separation unit, and an output control unit that controls the voice signal separated by the second separation unit to be output from a plurality of speakers.

Description

Technical Field

[0001] Embodiments of the present invention relate to an audio device and an audio control method.

Background Art

[0002] In a device for outputting sound, a method of extracting in-phase components between two channels from a two-channel stereo signal is known. For example, a method of separating components with high correlation and components with low correlation between two channels and adding the components with high correlation to extract the in-phase components is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the components with high correlation in the prior art include various weighted components, incorrect correlation components are added to the uncorrelated signal output unit. Therefore, when attempting to achieve sound image localization with the sound output from the speaker, the conventional sound image localization technology cannot reproduce correct sound image localization, and thus there may be a feeling of sound degradation or lack of presence.

[0005] The problem to be solved by the embodiments of the present invention is to provide an audio device and an audio control method capable of forming a high-quality sound image with an in-phase and equal-amplitude component audio signal.

Means for Solving the Problems

[0006] One embodiment of the present invention is an audio device that performs processing for outputting audio from a plurality of speakers, and includes a first separation unit that separates correlation components used to form sound image localization from each of a left input audio signal corresponding to a left channel and a right input audio signal corresponding to a right channel, a second separation unit that separates an audio signal component that becomes a co-phase and equal-amplitude component with an amplitude deviation of a predetermined value or less and a phase deviation within a predetermined range from the audio signal separated by the first separation unit, and an output control unit that controls the audio signal separated by the second separation unit to be output from the plurality of speakers.

Brief Description of the Drawings

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[0008] Exemplary embodiments of the present invention will be disclosed below.

[0009] (First Embodiment) FIG. 1 is a diagram showing an example of the hardware configuration of a display device 1 according to a first embodiment equipped with a DSP, which is an audio device to which an example of the present invention is applied. The display device 1 is a device capable of displaying video and outputting sound, such as a television. The display device 1 exemplified here includes a processor 11, a memory 12, a UI (User Interface) 13, a peripheral circuit 14, a communication circuit 15, an audio decoder 16, an audio input ADC (Analog Digital Converter) 17, a DSP (Digital Signal Processor) 21 (an example of an audio device), an amplifier 22, a speaker 23, and a display 31. Note that a speaker connected to a television may be provided with the function of the audio device of the present invention.

[0010] The processor 11 executes predetermined arithmetic processing and control processing according to the program stored in the memory 12. The memory 12 includes a main storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory), and an auxiliary storage device such as an SSD (Solid State Drive) or an HDD (Hard Disk Drive), and stores programs and various data necessary to realize the functions of the display device 1. The UI 13 is a unit that accepts user operations. The peripheral circuit 14 is a circuit that assists the operation of the processor 11, and can be, for example, a power supply circuit, an oscillation circuit, a reset circuit, or the like.

[0011] The communication circuit 15 is a circuit that acquires video signals, audio signals, etc. via an antenna, a communication network, etc. The audio decoder 16 is a device that decodes encrypted audio signals. The audio input ADC 17 is a device that converts analog audio signals into digital signals.

[0012] The DSP 21 is an audio device that performs predetermined processing on the audio signals acquired from the communication circuit 15, the audio decoder 16, or the audio input ADC 17. The DSP 21 can be configured using, for example, a CPU (Central Processing Unit), a memory, input / output ports, etc. The DSP 21 in this embodiment performs processing to optimize the output of audio to each of the plurality of speakers 23 so that the audio output from the plurality of speakers 23 built in the display device 1 forms a predetermined sound image localization. The audio signals processed by the DSP 21 are output to each speaker 23 via the amplifier 22.

[0013] FIG. 2 is a diagram showing an example of the configuration of the plurality of speakers 23 according to the first embodiment. In FIG. 2, the state when the display device 1 is viewed from the front side of the display 31 is illustrated. Note that in FIG. 2, the case where there are three speakers 23 shown in FIG. 1 is taken as an example.

[0014] As shown in FIG. 2, the display device 1 of the present embodiment includes a left speaker 23L, a right speaker 23R, and a center speaker 23C. The left speaker 23L is disposed near the left end of the lower part of the display 31. The right speaker 23R is disposed near the right end of the lower part of the display 31. The center speaker 23C is disposed at the center of the lower part of the display 31. That is, it is disposed between the left speaker 23L and the right speaker 23R. Alternatively, for example, the plurality of speakers may be constituted by a left speaker 23L installed on the left side of the listener, a right speaker 23R installed on the right side of the listener, and a center speaker 23C installed between the left speaker 23L and the right speaker 23R when viewed from the listener.

[0015] Note that the arrangement of the left speaker 23L, the right speaker 23R, and the center speaker 23C is an example and is not limited to the above.

[0016] FIG. 3 is a diagram showing an example of the functional configuration of the DSP 21 according to the first embodiment. The DSP 21 of the present embodiment includes a first separation unit 101, a second separation unit 102, and an output control unit 103. These functional units are realized by the cooperation of the DSP 21 which is the hardware shown in FIG. 1 and software. Further, at least one of these functional units may be constituted by dedicated hardware (such as a circuit).

[0017] The first separation unit 101 separates the correlation components from each of the Lch input signal and the Rch input signal which are audio signals input to the DSP 21. Specifically, it separates the independent components and the uncorrelated components and separates the correlation components. Then, it outputs the correlation components to the second separation unit 102. The Lch input signal is a signal corresponding to the left channel in the two-channel stereo reproduction of audio, and the Rch input signal is a signal corresponding to the right channel in the stereo reproduction. The input signal is also referred to as the input audio signal.

[0018] An independent component represents an audio signal that has no correlation between the left channel and the right channel and is output from either the left channel or the right channel. It is also a component corresponding to an end audio where the sound image is localized at the left end or the right end of the display 31 (an example of a predetermined area).

[0019] An uncorrelated component is a component of an audio signal corresponding to background audio where the degree of correlation between the audio signal output from the left channel and the audio signal output from the right channel is less than a predetermined value, and the range of the sound image is wider than that of the end audio.

[0020] A correlated component represents a signal output by the left channel and the right channel and having a degree of correlation equal to or greater than a predetermined value between the left channel and the right channel. It is also a component corresponding to intermediate audio where the sound image is localized inside the localization position of the sound image of the end audio. Furthermore, the correlated component includes an audio signal component that becomes a co-phase and equal-amplitude component corresponding to center audio where the sound image is localized at the center of the display 31 (an example of a predetermined area). The co-phase and equal-amplitude component is, for example, a signal in which the amplitude deviation is equal to or less than a predetermined value and the phase deviation is within a certain range. The predetermined value of the amplitude deviation is, for example, 1 dB or less as an example.

[0021] The second separation unit 102 receives the signal of the correlated component separated by the first separation unit 101. The co-phase and equal-amplitude component CC is separated from each of the Lch input signal and the Rch input signal that are correlated components. The correlated component is separated by the first separation unit 101, and the co-phase and equal-amplitude component is separated from the correlated component by the second separation unit 102. Thereby, the co-phase and equal-amplitude component can be separated.

[0022] The output control unit 103 assigns the signal generated from the in-phase and equal-amplitude components to the center speaker 23C as the Cch output signal and controls it to be output from the center speaker 23C. Further, from each of the Lch input signal and the Rch input signal, which are audio signals input to the DSP 21, the signals obtained by subtracting the signals generated from the in-phase and equal-amplitude components are assigned to the left speaker 23L and the right speaker 23R as the Lch output signal and the Rch output signal, respectively, and are controlled to be output from the left speaker 23L and the right speaker 23R.

[0023] FIG. 4 is a diagram showing an example of the configuration of the first separation unit 101 and the second separation unit 102 according to the first embodiment. First, the first separation unit 101 will be described. The first separation unit 101 illustrated here includes adaptive filters 201L and 201R (an example of a filter unit) and adaptive algorithms 211L and 211R (an example of a coefficient update unit).

[0024] The adaptive filters 201L and 201R output output signals ol(n) and or(n) by applying a finite impulse response based on predetermined coefficients to the left Lch input signal xl(n) and the right Rch input signal xr(n), respectively. That is, the Lch adaptive filter 201L corresponding to the left channel outputs the output signal ol(n) included in the Lch input signal by applying a finite impulse response based on the coefficients to the Lch input signal xl(n). The Rch adaptive filter 201R corresponding to the right channel outputs the output signal or included in the Rch input signal by applying a finite impulse response based on the coefficients to the Rch input signal xr(n).

[0025] The adaptive algorithms 211L and 211R are algorithms for optimizing the coefficients of the adaptive filters 201L and 201R. The adaptive algorithms 211L and 211R update the coefficients of the adaptive filters so that the values of the error signals el(n) and er(n) based on the difference between the target signals xl(n) - xr(n) and xr(n) - xl(n) based on the difference between the Lch input signal xl(n) and the Rch input signal xr(n), and the output signals ol(n) and or(n) output from the adaptive filters 201L and 201R are minimized. In this example, n corresponds to time.

[0026] Specifically, the Lch adaptive algorithm 211L corresponding to the left channel updates the coefficients of the adaptive filter so that the value of the error signal el(n), which is the difference between the value obtained by integrating a predetermined weight gl with the target signal xl(n) - xr(n), which is the difference between the Lch input signal xl(n) and the Rch input signal xr(n), and the output signal ol(n) output from the Lch adaptive filter 201L, is minimized.

[0027] Also, the Rch adaptive algorithm 211R corresponding to the right channel updates the coefficients of the adaptive filter so that the value of the error signal er(n), which is the difference between the value obtained by integrating a predetermined weight gr with the target signal xr(n) - xl(n), which is the difference between the Rch input signal xr(n) and the Lch input signal xl(n), and the output signal or(n) output from the Rch adaptive filter 201R, is minimized.

[0028] With the adaptive filters 201L and 201R whose coefficients are optimized by the adaptive algorithms 211L and 211R as described above, the independent components and uncorrelated components corresponding to the error signals el(n) and er(n) are separated from the input signals xl(n) and xr(n). Then, the correlated component cl(n) can be separated by subtracting the independent components and the uncorrelated component er(n) from the input signal xl(n). Similarly, the correlated component cr(n) can be separated by subtracting the independent components and the uncorrelated component el(n) from the input signal xr(n). The correlated components cl(n) and cr(n) are output to the second separation unit 102.

[0029] Moreover, with the above-described configuration, filtering (cancellation) of uncorrelated components by the adaptive filters 201L and 201R becomes unnecessary, a sharp change in the frequency characteristics of the filters is reduced, and generation of components that cause abnormal noise can be suppressed.

[0030] Next, the second separation unit 102 will be described. The second separation unit 102 exemplified here includes an adaptive filter 301 (an example of a filter unit) and an adaptive algorithm 311 (an example of a coefficient update unit).

[0031] The adaptive filter 301 outputs an output signal oc(n) by applying a finite impulse response based on predetermined coefficients to cl(n)−cr(n) obtained by subtracting the Rch input signal from the Lch input signal as an input signal. That is, the adaptive filter 301 outputs the output signal oc(n) included in the input signal by applying a finite impulse response based on coefficients to the input signal cl(n)−cr(n).

[0032] The adaptive algorithm 311 is an algorithm for optimizing the coefficients of the adaptive filter 301. The adaptive algorithm 311 updates the coefficients of the adaptive filter so that the value ec(n) of an error signal based on the difference between the target signal cl(n)+cr(n) based on the addition of the Lch input signal cl(n) and the Rch input signal cr(n), the target signal cl(n)+cr(n), and the output signal oc(n) output from the adaptive filter 301 is minimized.

[0033] Specifically, the adaptive algorithm 311 of the second separation unit 102 updates the coefficients of the adaptive filter so that the value ec(n) of an error signal, which is the difference between the value obtained by integrating the target signal cl(n)+cr(n) obtained by adding the Lch input signal cl(n) and the Rch input signal cr(n) with a predetermined weight gc and the output signal oc(n) output from the adaptive filter 301, is minimized.

[0034] The adaptive filter 301 with coefficients optimized by the adaptation algorithm 311 as described above outputs the CC of the independent component corresponding to the error signal ec(n) from the input signal cl(n) - cr(n), and separates the in-phase equal-amplitude components. Then, in order to combine the in-phase equal-amplitude component corresponding to the error signal ec(n) with the center component of the Lch input signal xl(n) and the Rch input signal xr(n), cc(n) is generated by multiplying the error signal ec(n) with the coefficient of the multiplier gcc set to 0.5.

[0035] Also, by subtracting the in-phase equal-amplitude component cc(n) from the Lch input signal xl(n) and subtracting the in-phase equal-amplitude component cc(n) from the Rch input signal xr(n), the Lch signal xl′(n) and the Rch signal xr′(n) that do not contain the in-phase equal-amplitude component cc(n) are generated.

[0036] The signal of the in-phase equal-amplitude component cc(n) is assigned to the center speaker as the Cch output signal. The Lch signal xl′(n) is assigned to the left speaker as the Lch output signal. And the Rch component xr′(n) is assigned to the right speaker as the Rch output signal.

[0037] FIG. 5 is a diagram showing an example of components included in the input signals xl(n) and xr(n) input to the first separation unit 101 according to the first embodiment. In this example, the Lch input signal xl(n) includes an uncorrelated component UL, an independent component IL, and correlated components CC, CL1, CL2, CR1, CR2, and the Rch input signal xr(n) includes an uncorrelated component UR, an independent component IR, and correlated components CC, CL1, CL2, CR1, CR2.

[0038] The signal level difference between the left and right input signals xl(n) and xr(n) input to the DSP 21 is such that the correlated component CC is 0 dB, the correlated components CL1 and CR1 are 3 dB, the correlated components CL2 and CR2 are 6 dB, the uncorrelated components UL and UR are ∞, and the independent components IL and IR are ∞. This embodiment shows a method of making the correlated component CC independent while having the signal level difference between the left and right output signals xl′(n) and xr′(n) output from the DSP 21 be the same as the signal level difference between the input signals xl(n) and xr(n).

[0039] The uncorrelated component UL included in the Lch input signal xl(n) has no correlation with the Rch input signal xr(n) and is a component corresponding to background audio. The uncorrelated component UR included in the Rch input signal xr(n) has no correlation with the Lch input signal xl(n) and is a component corresponding to background audio. The background audio is, for example, audio whose sound image is localized so as to spread over the entire left and right areas of the display 31.

[0040] The independent component IL included in the Lch input signal xl(n) has no correlation with the Rch input signal xr(n) and is a component corresponding to the left-end audio. The independent component IR included in the Rch input signal xr(n) has no correlation with the Lch input signal xl(n) and is a component corresponding to the right-end audio. The end audio is, for example, audio whose sound image is localized at the left and right ends or near the ends of the display 31. For example, the left-end audio has its sound image localized at the left end of the display 31, and the right-end audio has its sound image localized at the right end of the display 31.

[0041] In FIG. 5, the weight 1.0, which is the value integrated with the independent components IL and IR, indicates the output level (volume) difference of the audio between the left and right channels. That is, it is shown that all the left-end audio corresponding to the independent component IL is output from the left-channel side and not from the right-channel side, and all the right-end audio corresponding to the independent component IR is output from the right-channel side and not from the left-channel side.

[0042] The correlation components CC, CL1, CL2, CR1, and CR2 are correlated between the Rch input signal xr(n) and the Lch input signal xl(n), and are components corresponding to intermediate audio. The intermediate audio is, for example, audio where the sound image is localized inside the localization positions of the sound images on the left and right of the end audio. The correlation component CC is a component corresponding to audio where the sound image is localized at the central position in the left and right sound image ranges of the intermediate audio. The correlation component CL1 is a component corresponding to audio where the sound image is localized at a position to the left of the central position in the sound image range. The correlation component CL2 is a component corresponding to audio where the sound image is localized at a position to the left of the localization position of the audio of the correlation component CL1 and to the right of the localization position of the sound image on the left of the end audio in the sound image range. The correlation component CR1 is a component corresponding to audio where the sound image is localized at a position to the right of the central position in the sound image range. The correlation component CR2 is a component corresponding to audio where the sound image is localized at a position to the right of the localization position of the audio of the correlation component CR1 and to the left of the localization position of the sound image on the right of the end audio in the sound image range.

[0043] In FIG. 5, the weights (in this example, 0.90, 0.80, 0.70, 0.60, 0.44), which are the values integrated for each of the correlation components CC, CL1, CL2, CR1, and CR2, indicate the output level difference of the audio between the left and right channels. That is, it is shown that the output level from the left channel of the intermediate audio corresponding to the correlation components CL1 and CL2 is greater than the output level from the right channel. Also, it is shown that the output level difference between the left and right channels in the correlation component CL2 is greater than the output level difference between the left and right channels in the correlation component CL1. The same applies to the correlation components CR1 and CR2. Here, when the weight in the left channel is Wl and the weight in the right channel is Wr, the weights exemplified here are set so that 2 +Wr 2 is 1 or approximately 1. For example, the left and right weights of the correlation component CL1 are 0.90 2 +0.44 2 ≒1.0, and the left and right weights of the correlation component CL2 are 0.80 2 +0.64 2 =1.0. The same applies to the correlation components CR1 and CR2.

[0044] Based on the above input signals xl(n) and xr(n), and the differences between the target signals xl(n) - xr(n) and xr(n) - xl(n), the independent components IL and IR and the uncorrelated components UL and UR are separated.

[0045] FIG. 6 is a diagram showing an example of a method for separating the independent component IR and the uncorrelated component UR from the difference between the Lch input signal xl(n) and the Lch target signal xl(n) - xr(n) according to the first embodiment. The Lch target signal xl(n) - xr(n) is a signal obtained by subtracting the Rch input signal xr(n) from the Lch input signal xl(n) as described above. As shown in FIG. 6, since both the Lch input signal xl(n) and the Lch target signal xl(n) - xr(n) include the Lch independent component IL, the Lch uncorrelated component UL, and the correlation components CL1, CL2, CR1, and CR2, by taking the difference between the Lch input signal xl(n) and the Lch target signal xl(n) - xr(n), the Rch independent component IR and the Rch uncorrelated component UR included in the Rch input signal xr(n) can be separated.

[0046] FIG. 7 is a diagram showing an example of a method for separating the independent component IL and the uncorrelated component UL from the difference between the Rch input signal xr(n) and the Rch target signal xr(n) - xl(n) according to the first embodiment. The Rch target signal xr(n) - xl(n) is a signal obtained by subtracting the Lch input signal xl(n) from the Rch input signal xr(n) as described above. As shown in FIG. 7, since both the Rch input signal xr(n) and the Rch target signal xr(n) - xl(n) include the Rch independent component IR, the Rch uncorrelated component UR, and the correlation components CL1, CL2, CR1, and CR2, by taking the difference between the Rch input signal xr(n) and the Rch target signal xr(n) - xl(n), the Lch independent component IL and the Lch uncorrelated component UL included in the Lch input signal xl(n) can be separated.

[0047] Then, by taking the difference between the Lch independent component IL and the Lch uncorrelated component UL separated as described above and the Lch input signal xl(n), the Lch correlation components CC, CL1, CL2, CR1, CR2 corresponding to the left channel can be separated. Also, by taking the difference between the Rch independent component IR and the Rch uncorrelated component UR separated as described above and the Rch input signal xr(n), the Rch correlation components CC, CL1, CL2, CR1, CR2 corresponding to the right channel can be separated.

[0048] Next, FIG. 8 is a diagram showing an example of components included in the input signal to the second separation unit 102 according to the first embodiment. The correlation components CC, CL1, CL2, CR1, CR2 are output from the first separation unit 101 to the second separation unit 102. Specifically, the components included in the Lch input signal cl(n) output from the first separation unit 101 and the components included in the Rch input signal cr(n) are shown.

[0049] FIG. 9 is a diagram showing an example of a method for separating the in-phase and equal-amplitude components by the second separation unit according to the first embodiment. As shown in FIG. 9, the input signal is a signal obtained by subtracting the Rch input signal cr(n) from the Lch input signal cl(n). The input signal cl(n) - cr(n) represents the input signal to the adaptive filter. Also, the input signal cl(n) - cr(n) represents the input signal to the adaptive algorithm. The target signal is a signal obtained by adding the Lch input signal cl(n) and the Rch input signal cr(n).

[0050] The in-phase and equal-amplitude component CC, which is an independent component, is separated from the difference between the input signal cl(n) - cr(n) to the adaptive filter of the second separation unit 102 and the target signal cl(n) + cr(n). Since both the input signal cl(n) - cr(n) and the target signal cl(n) + cr(n) include the correlation components CL1, CL2, CR1, CR2, the in-phase and equal-amplitude component CC, which is an independent component, can be separated by taking the difference between the input signal cl(n) - cr(n) and the target signal cl(n) + cr(n).

[0051] FIG. 10 is a diagram showing an example of components included in the output signal according to the first embodiment. As shown in FIG. 10(a), the Cch output signal outputs the in-phase equal-amplitude component CC. For example, when the coefficient of the multiplier gcc is 0.5, the weight of the in-phase equal-amplitude component CC is 0.7. FIG. 10(b) shows the components included in the Lch output signal, the components included in the Rch output signal, and the signal level difference between the Lch output signal and the Rch output signal.

[0052] The component included in the Lch output signal is the result of subtracting the Cch output signal from the Lch input signal. Similarly, the component included in the Rch output signal is the result of subtracting the Cch output signal from the Rch input signal. Therefore, components that do not include the in-phase equal-amplitude component CC can be output. Thus, the Lch output signal can be output from the left speaker 23L, and the Rch output signal can be output from the right speaker 23R. Furthermore, the Cch output signal from which only the in-phase equal-amplitude component CC is separated can be output from the center speaker 23C.

[0053] Therefore, as shown by the signal level difference between the Lch output signal and the Rch output signal, the signal level difference of the output signal excluding the CC component is the same as the signal level difference of the input signal. Therefore, the components excluding the in-phase equal-amplitude component can generate the same sound image as the input signal.

[0054] FIG. 11 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the first embodiment. As shown in FIG. 11, the display device 1 includes a display 31, a left speaker 23L, a right speaker 23R, and a center speaker 23C. In this embodiment, the sound image can be localized at a plurality of positions by three speakers.

[0055] By allocating the Cch output signal to the center speaker 23C, the output control unit 103 can localize the sound image C of the in-phase equal-amplitude component CC at the installation position of the center speaker 23C. By allocating the Lch output signal to the left speaker 23L and the Rch output signal to the right speaker 23R, the output control unit 103 can localize the sound image UU of the uncorrelated components UL and UR so as to spread in the space between the left speaker 23L and the right speaker 23R.

[0056] Also, by allocating the Lch output signal to the left speaker 23L, the output control unit 103 can localize the sound image LL of the independent component IL at the installation position of the left speaker 23L. Similarly, by allocating the Rch output signal to the right speaker 23R, the output control unit 103 can localize the sound image RR of the independent component IR at the installation position of the right speaker 23R.

[0057] Furthermore, the output control unit 103 can localize the sound images L2, L1, R1, and R2 composed of the correlation components CL1, CL2, CR1, and CR2 by the left speaker 23L and the right speaker 23R.

[0058] Specifically, the sound image LL indicates the sound image on the left side of the Lch voice, the sound image RR indicates the sound image on the right side of the Rch voice, the sound image UU indicates the sound image of the background voice, the sound image C indicates the sound image of the Cch voice, the sound images L1 and L2 indicate the intermediate sound images between the Lch voice and the Cch voice, and the sound images R1 and R2 indicate the intermediate sound images between the Rch voice and the Cch voice.

[0059] The output control unit 103 of the present embodiment controls to output the Lch end voice generated from the Lch independent component IL from the left speaker 23L and controls to output the Rch end voice generated from the Rch independent component IR from the right speaker 23R. Thereby, the sound image LL on the left side of the end voice can be localized at the installation position of the left speaker 23L, and the sound image RR on the right side of the end voice can be localized at the installation position of the right speaker 23R.

[0060] Also, the output control unit 103 controls to output the Lch background sound generated from the Lch uncorrelated component UL from the left speaker 23L, and controls to output the Rch background sound generated from the Rch uncorrelated component UR from the right speaker 23R. Thereby, the sound image UU of the background sound can be localized so as to spread in the space between the installation positions of the left speaker 23L and the right speaker 23R.

[0061] Also, the output control unit 103 controls to output the Lch intermediate sound generated from the Lch correlated components CL1, CL2, CR1, CR2 from the left speaker 23L, and controls to output the Rch intermediate sound generated from the Rch correlated components CL1, CL2, CR1, CR2 from the right speaker 23R. Thereby, the sound images L1, L2, R1, R2 of the intermediate sound can be localized between the localization positions of the sound images LL, RR of the left and right end sounds.

[0062] Also, the output control unit 103 controls to output the Cch sound generated from the in-phase equal amplitude component CC from the center speaker 23C. Thereby, the sound image C of the center sound can be localized at the position of the center speaker 23C.

[0063] Thereby, by extracting the in-phase equal amplitude component from the stereo signal, high-quality sound images localized at the position of the center speaker can be formed without changing the sound image localization excluding the in-phase equal amplitude component CC. Also, by allocating to the center speaker 23C by the first separation unit 101 and the second separation unit 102, a Cch output signal with a clear localization of the sound image C can be generated.

[0064] FIG. 12 is a diagram showing an example of the configuration of a plurality of speakers according to the second embodiment. In FIG. 2, the state when the display device 1 is viewed from the front side of the display 31 is illustrated.

[0065] As shown in FIG. 12, the display device 1 of the present embodiment includes a left speaker 23L and a right speaker 23R. The left speaker 23L is disposed near the left end of the lower part of the display 31. The right speaker 23R is disposed near the right end of the lower part of the display 31. Alternatively, for example, the plurality of speakers may be constituted by a left speaker 23L installed on the left side of the listener and a right speaker 23R installed on the right side of the listener when viewed from the listener. Alternatively, for example, it may be constituted by a left speaker 23L and a right speaker 23R installed on both sides of the audio device.

[0066] Note that the arrangement of the left speaker 23L and the right speaker 23R is an example and is not limited to the above.

[0067] FIG. 13 is a diagram showing an example of the configuration of the first separation unit 101 and the second separation unit 102 according to the second embodiment. The first separation unit 101 is the same as that in the first embodiment.

[0068] Regarding the second separation unit 102, it is the same until the co-phase and co-amplitude component CC is separated. The second embodiment takes as an example the case where the center speaker 23C is removed and the filter circuit 302 is provided in the output control unit 103.

[0069] The co-phase and co-amplitude component CC separated by the second separation unit 102 is processed by the filter circuit 302. Then, by adding to the Lch input signal and the Rch input signal, an output signal in which only the co-phase and co-amplitude component CC of the Lch output signal and the Rch output signal is emphasized is generated.

[0070] For example, when the coefficient of the multiplier gcc is 0, the components of the Lch input signal and the Rch input signal are output without change. Also, when the coefficient of the multiplier gcc is 1, the co-phase and co-amplitude component CC is emphasized in the components of the Lch input signal and the Rch input signal and output. Therefore, the level of emphasis can be adjusted by the coefficient of the multiplier gcc.

[0071] FIG. 14 is a diagram showing an example of the relationship between the output location of each audio and the sound image in the second embodiment. As shown in FIG. 14, the display device 1 includes a display 31, a left speaker 23L, and a right speaker 23R. In the second embodiment, the sound image can be localized at a plurality of positions by two speakers.

[0072] As shown in FIG. 13, by the processing of the filter circuit 302, it becomes possible to emphasize only the sound image C composed of the in-phase equal-amplitude component CC. Thereby, the quality of the audio can be improved and the in-phase equal-amplitude component CC can be reproduced more clearly.

[0073] As described above, according to the present embodiment, an audio device that performs processing for outputting audio from a plurality of speakers, the correlation component used to form the sound image localization is separated by a first separation unit that separates the correlation component from the Lch input audio signal and the Rch input audio signal, the in-phase equal-amplitude component is separated by a second separation unit that separates the audio signal component having the same phase and equal amplitude from the correlation component, and by assigning the audio generated from the in-phase equal-amplitude component to the center speaker 23C, the quality of the sound image C localized by the audio output from the center speaker can be improved. Therefore, the in-phase equal-amplitude component CC can be reproduced more clearly.

[0074] Further, by controlling so as to assign and output the audio generated from the in-phase equal-amplitude component CC to the center speaker located between the two speakers of the audio device and to the left speaker and the right speaker located on both sides of the audio device which are the two speakers, and controlling so as to assign and output the audio signal obtained by subtracting the in-phase equal-amplitude component CC from the Lch input signal and the Rch input signal to the left speaker and the right speaker, the sound image localized at each speaker can be generated. As a result, it is possible to suppress the deterioration of the audio and the decrease in the sense of presence due to the overlapping of the sound images with each other.

[0075] Also, in the case of a left speaker and a right speaker located on both sides of an audio device that does not include a center speaker, by assigning the in-phase equal-amplitude component CC generated by the second separation unit to the Lch input signal and the Rch input signal and distributing the audio signal to the left speaker and the right speaker, it is possible to improve the quality of the sound image of the in-phase equal-amplitude component localized at the central position between the left speaker and the right speaker. Further, by generating the in-phase equal-amplitude component CC by the second separation unit, only the in-phase equal-amplitude components output from the left speaker and the right speaker can be emphasized. That is, it is possible to suppress the deterioration of the sound quality and the reduction of the sense of presence due to the overlapping of the sound images with each other.

[0076] A program for realizing the functions of the display device 1 (DSP21) as described above may be recorded and provided on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk), etc. in a file in a form installable on a computer or an executable form. Further, the program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, the program may be configured to be provided or distributed via a network such as the Internet.

[0077] As described above, the embodiments of the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0078] 1… indicates a device, 21… DSP (audio device), 23L… left speaker, 23R… right speaker, 23C… center speaker, 101… first separation unit, 102… second separation unit, 103… output control unit, 201L, 201R… adaptive filter (filter unit), 211L, 211R… adaptive algorithm (coefficient update unit), 301… adaptive filter, 311… adaptive algorithm, 302… filter circuit, C, L1, L2, LL, R1, R2, RR, UU… sound images

Claims

1. An audio device that performs processing to output audio from a plurality of speakers, a first separation unit that separates correlation components used to form a sound image localization from each of a left input audio signal corresponding to a left channel and a right input audio signal corresponding to a right channel; a second separation unit that separates audio signal components having the same phase and amplitude from the audio signal separated by the first separation unit; an output control unit that controls the audio signals separated by the second separation unit to be output from the plurality of speakers; An audio device comprising:

2. An audio device that performs processing to output audio from multiple speakers, the plurality of speakers include a left speaker disposed to the left of the listener when viewed from the listener, a right speaker disposed to the right of the listener, and a center speaker disposed between the left speaker and the right speaker; a first separation unit that separates correlation components used to form a sound image localization from each of a left input audio signal corresponding to a left channel and a right input audio signal corresponding to a right channel; a second separation unit that separates audio signal components having the same phase and amplitude from the audio signal separated by the first separation unit; an output control unit that controls the audio signal separated by the second separation unit to be output from the center speaker, controls the audio signal obtained by subtracting the audio signal separated by the second separation unit from the left input audio signal to be output from the left speaker, and controls the audio signal obtained by subtracting the audio signal separated by the second separation unit from the right input audio signal to be output from the right speaker; An audio device comprising:

3. the plurality of speakers include a left speaker disposed to the left of the listener and a right speaker disposed to the right of the listener, when viewed from the listener; The output control unit is control the left speaker to output an audio signal obtained by adding the audio signal separated by the second separation unit to the left input audio signal; control the right speaker to output an audio signal obtained by adding the audio signal separated by the second separation unit to the right input audio signal; 2. The audio device of claim 1.

4. An audio control method for performing processing for outputting audio from a plurality of speakers, comprising: A first step of separating correlation components used to form a sound image localization from each of a left input audio signal corresponding to a left channel and a right input audio signal corresponding to a right channel; A second step of separating audio signal components that are in-phase and in-amplitude components from the audio signal separated in the first step; a step of controlling the audio signals separated in the second step to be output from the plurality of speakers; 23. An audio control method comprising:

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