Audio device, audio control method and program

Abstract

To enable the formation of a high-quality sound image.SOLUTION: An audio device includes: a separation unit which separates, from a left input signal and a right input signal, independent components uncorrelated between a left channel and a right channel and corresponding to end sounds in which a sound image is localized at the left end or right end of a designated area, uncorrelated components uncorrelated between the left channel and right channel and corresponding to background sounds with a range of the sound image wider than the end sounds, and correlated components correlated between the left channel and right channel and corresponding to intermediate sounds in which the sound image is localized inside the localization position of the sound image of the right and left end sounds; and a sound image localization adjustment unit which adjusts at least one of the correlated components and independent components to localize the right and left sound images of the end sounds generated from the independent components at the right and left ends of the designated area, and localize the sound image of the intermediate sound generated from the correlated components between the localization positions of the right and left sound images of the end sounds.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD Embodiments of the present invention relate to an audio device, an audio control method, and a program. [Background technology]

[0002] In devices that output audio, sound image localization technology is used to separate correlated components, which are correlated between channels, and uncorrelated components, which are uncorrelated between channels, from a two-channel stereo signal, and to allow the user to perceive the location of a virtual sound source using these correlated and uncorrelated components. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-333698 Summary of the Invention [Problem to be solved by the invention]

[0004] When attempting to achieve sound image localization using sound output from multiple built-in speakers in a display device such as a television, conventional sound image localization technology may result in multiple sound images that should be separated overlapping each other, resulting in degradation of the sound and a lack of realism.

[0005] An object of the present invention is to provide an audio device, an audio control method, and a program that are capable of forming a high-quality sound image. [Means for solving the problem]

[0006] One embodiment of the present invention is an audio device that performs processing to output audio from a plurality of speakers, and includes: a separation unit that separates, from each of a left input signal corresponding to the left channel and a right input signal corresponding to the right channel, an independent component that corresponds to edge audio that is not correlated between the left channel and the right channel and whose sound image is localized at the left or right end of a predetermined region, an uncorrelated component that corresponds to background audio that is not correlated between the left channel and the right channel and whose sound image range is wider than the edge audio, and a correlated component that corresponds to intermediate audio that is correlated between the left channel and the right channel and whose sound image is localized inside the localization positions of the sound images of the left and right edge audio; a sound image localization adjustment unit that adjusts at least one of the correlated component and the independent component so that the left and right sound images of the edge audio generated from the independent component are localized at the left and right ends of the predetermined region, and the sound image of the intermediate audio generated from the correlated component is localized between the localization positions of the left and right sound images of the edge audio; and an output control unit that outputs the edge audio, the background audio, and the intermediate audio from the plurality of speakers. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a hardware configuration of a display device according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a configuration of a plurality of speakers according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of the functional configuration of a DSP according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of the separation unit according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of components included in an input signal according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of a method for separating independent components and uncorrelated components from the difference between the Lch input signal and the Lch target signal according to the first embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a method for separating an independent component and an uncorrelated component from the difference between the Rch input signal and the Rch target signal according to the first embodiment. [Figure 8]FIG. 8 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the first embodiment. [Figure 9] FIG. 9 is a diagram showing an example of sound image localization adjustment processing for correlation components according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of processing by the DSP according to the first embodiment. [Figure 11] FIG. 11 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the second embodiment. [Figure 12] FIG. 12 is a diagram illustrating an example of the functional configuration of a DSP according to the second embodiment. [Figure 13] FIG. 13 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the second embodiment. [Figure 14] FIG. 14 is a diagram showing an example of sound image localization adjustment processing for independent components and uncorrelated components according to the second embodiment. [Figure 15] FIG. 15 is a flowchart showing an example of processing by the DSP according to the second embodiment. [Figure 16] FIG. 16 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the third embodiment. [Figure 17] FIG. 17 is a diagram illustrating an example of the functional configuration of a DSP according to the third embodiment. [Figure 18] FIG. 18 is a diagram illustrating an example of an input signal to the second separator according to the third embodiment. [Figure 19] FIG. 19 is a diagram showing an example of a method for separating an independent component from the difference between the Lch input signal and the Lch target signal according to the third embodiment. [Figure 20] FIG. 20 is a diagram showing an example of a method for separating an independent component from the difference between the Rch input signal and the Rch target signal according to the third embodiment. [Figure 21] FIG. 21 is a diagram showing an example of sound image localization adjustment processing for correlation components according to the third embodiment. [Figure 22] FIG. 22 is a diagram illustrating an example of components included in an input signal according to the third embodiment. [Figure 23] FIG. 23 is a diagram showing an example of a method for separating an independent component from the difference between the Lch input signal and the Lch target signal according to the third embodiment. [Figure 24] FIG. 24 is a diagram showing an example of a method for separating an independent component from the difference between the Rch input signal and the Rch target signal according to the third embodiment. [Figure 25] FIG. 25 is a flowchart showing an example of processing by the DSP according to the third embodiment. [Figure 26] FIG. 26 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the fourth embodiment. [Figure 27] FIG. 27 is a diagram illustrating an example of the functional configuration of a DSP according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Illustrative embodiments of the present invention are disclosed below.

[0009] (First embodiment) 1 is a diagram showing an example of the hardware configuration of a display device 1 according to the first embodiment. The display device 1 is a device capable of displaying video and outputting audio, and may be, for example, a television. The display device 1 illustrated 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, and a speaker 23.

[0010] The processor 11 executes predetermined arithmetic processing and control processing in accordance with programs stored in the memory 12. The memory 12 includes a main storage device such as a random access memory (RAM) or a read only memory (ROM) and an auxiliary storage device such as a solid state drive (SSD) or a hard disk drive (HDD), 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 circuits 14 are circuits that assist the operation of the processor 11, and may be, for example, a power supply circuit, an oscillation circuit, a reset circuit, etc.

[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 information processing device that performs predetermined processing on 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, an input / output port, etc. The DSP 21 of this embodiment performs processing to optimize audio output for each of the multiple speakers 23 built into the display device 1 so that audio output from the multiple speakers 23 forms a predetermined sound image. The audio signals processed by the DSP 21 are output to each speaker 23 via an amplifier 22.

[0013] Fig. 2 is a diagram showing an example of the configuration of a plurality of speakers 23 according to the first embodiment. Fig. 2 illustrates the display device 1 as viewed from the front side of the display 31.

[0014] As shown in FIG. 2, the display device 1 of this embodiment includes a left main speaker 23ML (an example of a first left speaker), a right main speaker 23MR (an example of a first right speaker), a left side speaker 23SL (an example of a second left speaker), and a right side speaker 23SR (an example of a second right speaker). The left main speaker 23ML is located near the left end of the lower part of the display device 1 (display 31). The right main speaker 23MR is located near the right end of the lower part of the display device 1. The left side speaker 23SL is located on the left side of the left main speaker 23ML. The right side speaker 23SR is located on the right side of the display device 1 to the right of the right main speaker 23MR.

[0015] The above-mentioned arrangement of the left main speaker 23ML, the right main speaker 23MR, the left side speaker 23SL, and the right side speaker 23SR is an example, and is not limited to the above.

[0016] 3 is a diagram showing an example of the functional configuration of the DSP 21 according to the first embodiment. The DSP 21 of this embodiment includes a separation unit 101, a sound image localization adjustment unit 102, and an output control unit 103. These functional units are configured by cooperation between hardware and software that constitute the DSP 21. Furthermore, at least one of these functional units may be configured by dedicated hardware (circuits, etc.).

[0017] The separation unit 101 separates independent components, uncorrelated components, and correlated components from each of the Lch input signal and Rch input signal, which are audio signals input to the DSP 21. The Lch input signal is a signal corresponding to the left channel in two-channel stereo reproduction of audio, and the Rch input signal is a signal corresponding to the right channel in the stereo reproduction.

[0018] An independent component is a component that has no correlation between the left and right channels and corresponds to edge audio whose sound image is localized at the left or right edge of the display 31 (an example of a predetermined area). An uncorrelated component is a component that has no correlation between the left and right channels and corresponds to background audio whose sound image range is wider than that of the edge audio. A correlated component is a component that has a correlation between the left and right channels and corresponds to intermediate audio whose sound image is localized inside the localization position of the sound image of the edge audio.

[0019] The sound image localization adjustment unit 102 performs a sound image localization adjustment process to localize the sound images of the sounds output from the multiple speakers 23 (in this embodiment, the left main speaker 23ML, the right main speaker 23MR, the left side speaker 23SL, and the right main speaker 23MR) in appropriate locations. The sound image localization adjustment process of this embodiment includes a process of adjusting at least one of the correlated components and the independent components so that the left and right sound images of the end audio are localized at the left and right ends of the display 31 (display device 1) and the sound image of the intermediate audio is localized between the left and right localization positions of the sound images of the end audio.

[0020] The output control unit 103 outputs the edge audio generated from the independent components, the background audio generated from the uncorrelated components, and the intermediate audio generated from the intermediate components from the corresponding speakers 23. In this embodiment, the Lch edge audio generated from the independent components separated from the Lch input signal and the Lch background audio generated from the uncorrelated components separated from the Lch input signal are output from the left side speaker 23SL. The Rch edge audio generated from the independent components separated from the Rch input signal and the Rch background audio generated from the uncorrelated components separated from the Rch input signal are output from the right side speaker 23SR. The Lch intermediate audio generated from the correlated components separated from the Lch input signal is output from the left main speaker 23ML. The Rch intermediate audio generated from the correlated components separated from the Rch input signal is output from the right main speaker 23MR.

[0021] 4 is a diagram showing an example of the configuration of the separation unit 101 according to the first embodiment. The 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).

[0022] The adaptive filters 201L and 201R output output signals ol and or by applying finite impulse responses based on predetermined coefficients xl0 to xl7 and xr0 to xr7 to the left and right input signals il and ir, respectively. That is, the Lch adaptive filter 201L corresponding to the left channel applies a finite impulse response based on coefficients xl0 to xl7 to the Lch input signal il, outputting the output signal ol included in the Lch input signal. The Rch adaptive filter 201R corresponding to the right channel applies a finite impulse response based on coefficients xr0 to xr7 to the Rch input signal ir, outputting the output signal or included in the Rch input signal. Note that, although the number of taps of the finite impulse response is 8 in this example, the present invention is not limited to this.

[0023] The adaptive algorithms 211L and 211R are algorithms for optimizing the coefficients xl0 to xl7 and xr0 to xr7 of the adaptive filters 201L and 201R. The adaptive algorithms 211L and 211R update the coefficients xl(n) and xr(n) so as to minimize the values ​​of the error signals el(n) and er(n) based on the difference between the target signals tl and tr, which are based on the difference between the Lch input signal il and the Rch input signal ir, and the output signals ol and or output from the adaptive filters 201L and 201R. In this example, n corresponds to the number of taps, 8, of the adaptive filters 201L and 201R, and takes a value between 0 and 7. The Lch adaptive algorithm 211L corresponding to the left channel updates the coefficient xl(n) so as to minimize the error signal value el(n), which is the difference between the output signal ol output from the Lch adaptive filter 201L and the value obtained by multiplying the target signal tl, which is the difference (il-ir) between the Lch input signal il and the Rch input signal ir, by a predetermined weight gl. The Rch adaptive algorithm 211R corresponding to the right channel updates the coefficient xr(n) so as to minimize the error signal value er(n), which is the difference between the output signal or output from the Rch adaptive filter 201R and the value obtained by multiplying the target signal tr, which is the difference (ir-il) between the Rch input signal ir and the Lch input signal il, by a predetermined weight gr.

[0024] The adaptive filters 201L, 201R, whose coefficients xl0 to xl7, xr0 to xr7 are optimized by the adaptive algorithms 211L, 211R described above, separate the independent and uncorrelated components corresponding to the error signals el(n), er(n) from the input signals il, ir. Then, by subtracting the independent and uncorrelated components from the input signals, the correlated components can be separated. Furthermore, the above-described configuration eliminates the need for the adaptive filters 201L, 201R to filter (eliminate) uncorrelated components, reduces abrupt changes in the frequency characteristics of the filters, and suppresses the generation of components that cause abnormal noise.

[0025] 5 is a diagram showing an example of components included in input signals i, ir according to the first embodiment. In this example, the Lch input signal i includes an uncorrelated component UL, an independent component IL, and correlated components CC, CL1, CL2, CR1, and CR2, and the Rch input signal ir includes an uncorrelated component UR, an independent component IR, and correlated components CC, CL1, CL2, CR1, and CR2.

[0026] The uncorrelated component UL contained in the Lch input signal il is a component that is uncorrelated with the Rch input signal ir and corresponds to background sound. The uncorrelated component UR contained in the Rch input signal ir is a component that is uncorrelated with the Lch input signal il and corresponds to background sound. The background sound is, for example, sound whose sound image is localized so as to spread across the entire left and right areas of the display 31.

[0027] The independent component IL included in the Lch input signal il is uncorrelated with the Rch input signal ir and corresponds to the left edge audio. The independent component IR included in the Rch input signal ir is uncorrelated with the Lch input signal il and corresponds to the right edge audio. The edge audio is, for example, audio whose sound image is localized at or near the left or right edge of the display 31. For example, the sound image of the left edge audio is localized at the left edge of the display 31, and the sound image of the right edge audio is localized at the right edge of the display 31. In FIG. 5, the weight 1.0, which is the value integrated into the independent components IL and IR, indicates the difference in audio output level (volume) between the left and right channels. In other words, it is shown that the left edge audio corresponding to the independent component IL is entirely output from the left channel and not from the right channel, and the right edge audio corresponding to the independent component IR is entirely output from the right channel and not from the left channel.

[0028] The correlation components CC, CL1, CL2, CR1, and CR2 are correlated between the Rch input signal ir and the Lch input signal il, and are components corresponding to middle audio. Middle audio is, for example, audio whose sound image is localized inside the localization positions of the left and right sound images of the end audio. The correlation component CC is a component corresponding to audio whose sound image is localized in the center position of the left and right sound image range of the middle audio. The correlation component CL1 is a component corresponding to audio whose sound image is localized to a position to the left of the center position in the sound image range. The correlation component CL2 is a component corresponding to audio whose sound image is localized to the left of the localization position of the sound of the correlation component CL1 in the sound image range and to the right of the localization position of the left sound image of the end audio. The correlation component CR1 is a component corresponding to audio whose sound image is localized to the right of the center position in the sound image range. The correlation component CR2 is a component corresponding to a sound whose sound image is localized to the right of the localization position of the sound of the correlation component CR1 and to the left of the localization position of the sound image on the right side of the end sound in the sound image range.

[0029] In Fig. 5, the weights (0.90, 0.80, 0.70, 0.60, 0.44 in this example) which are values ​​multiplied by the correlation components CC, CL1, CL2, CR1, and CR2 respectively indicate the difference in audio output level 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. It is also shown that the difference in output level between the left and right channels in the correlation component CL2 is greater than the difference in output level between the left and right channels in the correlation component CL1. The same is true for the correlation components CR1 and CR2. Note that the weights exemplified here are such that, when the weight for the left channel is Wl and the weight for the right channel is Wr, Wl 2 +Wr 2 is set to be 1 or approximately 1. For example, the left and right weights of the correlation component CL1 are set to 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 is true for the correlation components CR1 and CR2.

[0030] Based on the difference between the input signals il, ir and the target signals tl, tr, the independent components IL, IR and the uncorrelated components UL, UR can be separated.

[0031] 6 is a diagram showing an example of a method for separating an independent component IR and an uncorrelated component UR from the difference between an Lch input signal iL and an Lch target signal tL according to the first embodiment. As described above, the Lch target signal tL is a signal obtained by subtracting the Rch input signal ir from the Lch input signal iL. As shown in FIG. 6, since both the Lch input signal iL and the Lch target signal tL contain an Lch independent component IL, an Lch uncorrelated component UL, and correlated components CL1, CL2, CR1, and CR2, the Rch independent component IR and Rch uncorrelated component UR contained in the Rch input signal ir can be separated by taking the difference between the Lch input signal iL and the Lch target signal tL.

[0032] 7 is a diagram showing an example of a method for separating an independent component IL and an uncorrelated component UL from the difference between an Rch input signal ir and an Rch target signal tr according to the first embodiment. As described above, the Rch target signal tr is a signal obtained by subtracting the Lch input signal il from the Rch input signal ir. As shown in FIG. 7, since both the Rch input signal ir and the Rch target signal tr contain an Rch independent component IR, an Rch uncorrelated component UR, and correlated components CL1, CL2, CR1, and CR2, the Lch independent component IL and the Lch uncorrelated component UL contained in the Lch input signal il can be separated by taking the difference between the Rch input signal ir and the Rch target signal tr.

[0033] Then, by taking the difference between the separated Lch independent component IL and Lch uncorrelated component UL and the Lch input signal il, the Lch correlated components CC, CL1, CL2, CR1, and CR2 corresponding to the left channel can be separated.Furthermore, by taking the difference between the separated Rch independent component IR and Rch uncorrelated component UR and the Rch input signal ir, the Rch correlated components CC, CL1, CL2, CR1, and CR2 corresponding to the right channel can be separated.

[0034] Fig. 8 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the first embodiment. In Fig. 8, sound image LL indicates the sound image on the left side of the end sound, and sound image RR indicates the sound image on the right side of the end sound. Sound image UU indicates the sound image of the background sound. Sound images C, L1, L2, R1, and R2 indicate the sound images of the intermediate sounds.

[0035] The output control unit 103 of this embodiment outputs the Lch end sound generated from the Lch independent component IL from the left side speaker 23SL, and outputs the Rch end sound generated from the Rch independent component IR from the right side speaker 23SR. This allows the left sound image LL of the end sound to be localized at the installation position of the left side speaker 23SL, and the right sound image RR of the end sound to be localized at the installation position of the right side speaker 23SR.

[0036] Furthermore, the output control unit 103 outputs the Lch background sound generated from the Lch uncorrelated component UL from the left side speaker 23SL, and outputs the Rch background sound generated from the Rch uncorrelated component UR from the right side speaker 23SR. This allows the sound image UU of the background sound to be localized so as to spread in the space between the installation positions of the left side speaker 23SL and the right side speaker 23SR.

[0037] Furthermore, the output control unit 103 outputs the Lch intermediate sound generated from the Lch correlation components CC, CL1, CL2, CR1, and CR2 from the left main speaker 23ML, and outputs the Rch intermediate sound generated from the Rch correlation components CC, CL1, CL2, CR1, and CR2 from the right main speaker 23MR. This allows the sound images C, L1, L2, R1, and R2 of the intermediate sounds to be localized between the localization positions of the sound images LL and RR of the left and right end sounds.

[0038] At this time, the sound image localization adjustment unit 102 of this embodiment adjusts the left and right weights of the correlation components CC, CL1, CL2, CR1, and CR2 so that the leftmost sound image L2 of the intermediate sound is localized at the installation position of the left main speaker 23ML, and the rightmost sound image R2 is localized at the installation position of the right main speaker 23MR.

[0039] 9 is a diagram showing an example of sound image localization adjustment processing for correlation components CC, CL1, CL2, CR1, and CR2 according to the first embodiment. In FIG. 9, the upper part illustrates a state before adjustment, and the lower part illustrates a state after adjustment. In the state before adjustment, the right channel weight of the left-end correlation component CL2 is a value greater than 0 (0.44 in this example), so the left-end sound image L2 of the intermediate sound is localized inward from the installation position of the left main speaker 23ML. Similarly, the left channel weight of the right-end correlation component CR2 is a value greater than 0 (0.44 in this example), so the right-end sound image R2 of the intermediate sound is localized inward from the installation position of the right main speaker 23MR.

[0040] 9, the left-end sound image L2 of the intermediate sound can be localized at the installation position of the left main speaker 23ML by setting the right channel weight of the left-end correlation component CL2, i.e., the output level from the right main speaker 23MR, to 0 and adjusting the other weights as appropriate. Similarly, the right-end sound image R2 of the intermediate sound can be localized at the installation position of the right main speaker 23MR by setting the left channel weight of the right-end correlation component CR2, i.e., the output level from the left main speaker 23ML, to 0 and adjusting the other weights as appropriate.

[0041] 10 is a flowchart showing an example of processing by the DSP 21 according to the first embodiment. In step S101, the separation unit 101 separates independent components IL and IR, uncorrelated components UL and UR, and correlated components CC, CL1, CL2, CR1, and CR2 from the input signals il and ir. That is, the separation unit 101 separates the Lch independent component IL, the Lch uncorrelated component UL, and the Lch correlated components CC, CL1, CL2, CR1, and CR2 from the Lch input signal il, and the separation unit 101 separates the Rch independent component IR, the Rch uncorrelated component UR, and the Rch correlated components CC, CL1, CL2, CR1, and CR2 from the Rch input signal ir.

[0042] In step S102, the sound image localization adjustment unit 102 performs sound image localization adjustment processing on the independent components and correlated components so that the left and right sound images LL and RR of the end audio are localized at the installation positions of the left and right side speakers 23SL and 23R, respectively (an example of the left and right ends of the display device 1), and the sound images C, L1, L2, R1, and R2 of the middle audio are localized between the localization positions of the left and right sound images LL and RR of the end audio. At this time, for example, the Lch independent component IL is adjusted so that the output level of the R channel is 0, and the Rch independent component IR is adjusted so that the output level of the LR channels is 0. Furthermore, the correlated components CC, CL1, CL2, CR1, and CR2 are adjusted so that the output level of the R channel of the leftmost component is 0 and the output level of the L channel of the rightmost component is 0, as exemplified in FIG. 9, for example.

[0043] In step S103, the output control unit 103 outputs the end sound generated from the independent components and the background sound generated from the uncorrelated components from the side speakers 23SL and 23SR. As a result, the sound image LL on the left side of the end sound is localized at the installation position of the left side speaker 23SL, and the sound image RR on the right side of the end sound is localized at the installation position of the right side speaker 23SR. In addition, the sound image UU of the background sound is localized so as to spread in the space between the installation positions of the left side speaker 23SL and the right side speaker 23SR.

[0044] Furthermore, in step S104, the output control unit 103 outputs the intermediate sound generated from the correlation components from the main speakers 23ML and 23MR. As a result, the sound images C, L1, L2, R1, and R2 of the intermediate sound are localized between the left and right sound images LL and RR of the end sound. Note that steps S103 and S104 are actually executed in parallel.

[0045] As described above, according to this embodiment, an input signal is separated into independent components, uncorrelated components, and correlated components. Intermediate audio generated from the correlated components is output from the main speakers 23ML and 23MR, and edge audio generated from the independent components is output from the side speakers 23SL and 23R, which are positioned outside the main speakers 23ML and 23MR. This allows the sound images LL and RR of the edge audio to be localized at the edges of the display 31, and a wide area can be secured for localizing the sound images C, L1, L2, R1, and R2 of the intermediate audio. This prevents audio degradation and a reduction in the sense of realism caused by the sound images C, L1, L2, R1, and R2 of the intermediate audio and the sound images LL and RR of the edge audio overlapping with each other. Furthermore, by outputting background audio generated from uncorrelated components from the side speakers 23SL and 23SR, the sound image UU of the background audio can be localized so that it spreads across the entire left and right areas of the display 31. This makes it possible to form a high-quality sound image and output high-quality audio with a high sense of presence.

[0046] Other embodiments will be described below with reference to the drawings, but descriptions of parts that are the same as or similar to the first embodiment will be omitted as appropriate.

[0047] (Second embodiment) 11 is a diagram showing an example of the configuration of the multiple speakers 23 of the display device 1 according to the second embodiment. In this embodiment, the side speakers 23SL and 23SM of the first embodiment do not exist. That is, in this embodiment, the end audio, background audio, and middle audio are all output from the main speakers 23ML and 23MR.

[0048] Fig. 12 is a diagram showing an example of the functional configuration of the DSP 21 according to the second embodiment. Fig. 13 is a diagram showing an example of the relationship between the output location of each sound and the sound image according to the second embodiment.

[0049] As shown in FIG. 12, the output control unit 103 of this embodiment outputs the Lch end audio, the Lch background audio, and the Lch intermediate audio to the left main speaker 23ML, and outputs the Rch end audio, the Rch background audio, and the Rch intermediate audio to the right main speaker 23MR.

[0050] 13, the sound image localization adjustment unit 102 of this embodiment adjusts the independent components so that the left sound image LL of the end audio is localized to the left of the installation position of the left main speaker 23ML, and the right sound image RR of the end audio is localized to the right of the installation position of the right main speaker 23MR. Furthermore, the sound image localization adjustment unit 102 of this embodiment adjusts the uncorrelated components so that the left end of the sound image UU of the background audio reaches to the left of the installation position of the left main speaker 23ML, and the right end of the sound image UU reaches to the right of the installation position of the right main speaker 23MR. Furthermore, the sound image localization adjustment unit 102 of this embodiment adjusts the correlated components so that the left end sound image L2 of the intermediate audio is localized at the installation position of the left main speaker 23ML, and the right end sound image R2 of the intermediate audio is localized at the installation position of the right main speaker 23MR.

[0051] 14 is a diagram showing an example of sound image localization adjustment processing for the independent components IL, IR and the uncorrelated components UL, UR according to the second embodiment. The sound image localization adjustment unit 102 of this embodiment adjusts the independent components IL, IR and the uncorrelated components UL, UR by utilizing crosstalk canceling.

[0052] In FIG. 14 , the components indicated by dashed lines correspond to correction components for achieving crosstalk cancellation. Specifically, as Lch components, a correction component −0.96*IR′, which is out of phase with the Rch independent component 1.96*IR, and a correction component −0.96*UR′, which is out of phase with the Rch uncorrelated component 1.96*UR, are added. Furthermore, as Rch components, a correction component −0.96*IL′, which is out of phase with the Lch independent component 1.96*IL, and a correction component −0.96*UL′, which is out of phase with the Lch uncorrelated component 1.96*UL, are added. Such correction components can be generated, for example, using a known crosstalk canceling circuit. By using such correction components, the left sound image LL of the end audio can be shifted to the left of the installation position of the left main speaker 23ML, and the right sound image RR of the end audio can be shifted to the right of the installation position of the right main speaker 23MR. Furthermore, the sound image UU of the background sound can be expanded so that its left end reaches to the left of the installation position of the left main speaker 23ML and its right end reaches to the right of the installation position of the right main speaker 23MR.

[0053] 15 is a flowchart showing an example of processing by the DSP 21 according to the second embodiment. In step S201, the separation unit 101 separates the input signals il and ir into independent components IL and IR, uncorrelated components UL and UR, and correlated components CC, CL1, CL2, CR1, and CR2.

[0054] In step S202, the sound image localization adjustment unit 102 performs sound field localization tonality processing to adjust independent components so that the left sound image LL of the end audio is localized to the left of the installation position of the left main speaker 23ML and the right sound image RR of the end audio is localized to the right of the installation position of the right main speaker 23MR. The sound image localization adjustment unit 102 also performs sound field localization adjustment processing to adjust uncorrelated components so that the left end of the sound image UU of the background audio reaches to the left of the installation position of the left main speaker 23ML and the right end of the sound image UU reaches to the right of the installation position of the right main speaker 23MR. The sound image localization adjustment unit 102 also performs sound field localization adjustment processing to adjust correlated components so that the left end sound image L2 of the intermediate audio is localized at the installation position of the left main speaker 23ML and the right end sound image R2 of the intermediate audio is localized at the installation position of the right main speaker 23MR.

[0055] In step S203, the output control unit 103 outputs the edge audio generated from the independent components, the background audio generated from the uncorrelated components, and the intermediate audio generated from the correlated components from the main speakers 23ML and 23MR. As a result, the left and right sound images LL and RR of the edge audio are localized at positions outside the left and right main speakers 23ML and 23MR, respectively, and the sound images C, L1, L2, R1, and R2 of the intermediate audio are localized between the left and right sound images LL and RR of the edge audio. In addition, the sound image UU of the background audio is localized so that its left edge reaches to the left of the installation position of the left main speaker 23ML and its right edge reaches to the right of the installation position of the right main speaker 23MR.

[0056] As described above, according to this embodiment, the sound images LL and RR of the end sound generated from the independent components can be localized near the left and right ends of the display 31 without using the side speakers 23SL and 23SM, and a wide area can be secured for localizing the sound images C, L1, L2, R1, and R2 of the middle sound. Also, the sound image UU of the background sound can be localized so that it spreads across the entire left and right area of ​​the display 31. This makes it possible to form a high-quality sound image using two speakers, and to output high-quality sound with a high sense of presence while suppressing increases in costs.

[0057] (Third embodiment) 16 is a diagram showing an example of the configuration of multiple speakers 30 of a display device 1 according to a third embodiment. In this embodiment, an example is shown in which three center speakers are added to the speakers in the first embodiment. The display device 1 of this embodiment includes a left main speaker 30ML (an example of a first left speaker), a right main speaker 30MR (an example of a first right speaker), a left side speaker 30SL (an example of a second left speaker), and a right side speaker 30SR (an example of a second right speaker), as well as a left center speaker 30SCL (an example of a third left speaker), a right center speaker 30SCR (an example of a third right speaker), and a center speaker 30SC.

[0058] The left main speaker 30ML is located near the left edge of the lower part of the display 31. The right main speaker 30MR is located near the right edge of the lower part of the display 31. The left side speaker 30SL is located on the left side of the display 31, at a position above and to the left of the left main speaker 30ML. The right side speaker 30SR is located on the right side of the display 31, at a position above and to the right of the right main speaker 30MR. Furthermore, the center speaker 30SC is located below the center of the display 31. The left center speaker 30SCL is located between the center speaker 30SC and the left main speaker 30ML. The right center speaker 30SCR is located between the center speaker 30SC and the right main speaker 30MR.

[0059] The sound images LL and RR are output from the left side speaker 30SL and the right side speaker 30SR and are end sounds localized at the positions of the left side speaker 30SL and the right side speaker 30SR. The sound images L2 and R2 are output from the left main speaker 30ML and the right main speaker 30MR and are left and right main sounds localized at the positions of the left main speaker 30ML and the right main speaker 30MR. The sound images L1 and R1 are left and right center sounds output from the left center speaker 30SCL and the right center speaker 30SCR and are localized at the positions of the left center speaker 30SCL and the right center speaker 30SCR. The sound image C is a center sound output from the center speaker 30SC and is localized at the position of the center speaker 30SC.

[0060] Therefore, independent audio components are output from each speaker. Note that the above speaker arrangement is an example and is not limited to the above. That is, the arrangement position may be at the top instead of the bottom. Furthermore, although an example is shown in which end audio, background audio, and middle audio are assigned to each speaker, the number of speakers is not limited.

[0061] 17 is a diagram showing an example of the functional configuration of the DSP 21 according to the third embodiment. The DSP 21 according to the third embodiment includes separation units 301-303, sound image localization adjustment units 311-312, and output control units 321-327.

[0062] The separation unit includes a first separation unit 301, a second separation unit 302, and a third separation unit 303. The first separation unit 301 separates each of an Lch input signal and an Rch input signal, which are audio signals input to the DSP 21, into independent and uncorrelated components, and correlated components. The input signals are also referred to as input audio signals. The first separation unit 301 then sends the independent and uncorrelated components to output control units 321 and 322. The first separation unit 301 further sends the correlated components to a first sound image localization adjustment unit 311. The Lch input signal is a signal corresponding to the left channel in two-channel stereo reproduction of audio, and the Rch input signal is a signal corresponding to the right channel in the stereo reproduction. The uncorrelated components indicate, for example, that the degree of correlation between the audio signal output from the left channel and the audio signal output from the right channel is lower than a predetermined value. The correlated components indicate, for example, that the degree of correlation between the left channel and the right channel is equal to or higher than a predetermined value.

[0063] Second separation section 302 separates each of the Lch input signal and Rch input signal, which are audio signals input from first sound image localization adjustment section 311, into a second correlated component and a second independent component. Then, it sends the second independent component to output control sections 323 and 324. It also sends the second correlated component to second sound image localization adjustment section 312. Third separation section 303 similarly separates each of the Lch input signal and Rch input signal, which are audio signals input from second sound image localization adjustment section 312, into a third correlated component and a third independent component. It then sends the third independent component to output control sections 325 and 326. It also sends the third correlated component to output control section 327. Note that although the description has been given up to third separation section 303 as an example, a plurality of separation sections may be provided.

[0064] The sound image localization adjustment unit includes a first sound image localization adjustment unit 311 and a second sound image localization adjustment unit 312. The first sound image localization adjustment unit 311 adjusts the weights of the left and right channels so as to derive a second independent component from the correlated component input from the first separation unit 301. This allows weight adjustment to be made from the correlated component to the second independent component and the second correlated component, and makes it possible to derive the second independent component that localizes a sound image at the position of the speakers. In other words, the correlated component is adjusted to the second independent component and the second correlated component so that the sound image is localized at the positions of the left main speaker 30ML and the right main speaker 30MR.

[0065] The second sound image localization adjustment unit 312 performs the same processing as the first sound image localization adjustment unit 311. It adjusts the weights of the left and right channels so as to derive a third independent component from the second correlated component of the second separation unit 302. This allows weight adjustment from the second correlated component to the third independent component and the third correlated component, making it possible to derive a third independent component that localizes a sound image at the position of the speakers. In other words, the second correlated component is adjusted to the third independent component and the third correlated component so that sound images are localized at the positions of the left center speaker 30SCL and the right center speaker 30SCR.

[0066] Each speaker is assigned to the output control units 321 to 327. For example, the output control unit 321 is assigned to the left side speaker 30SL and controls the output to output the Lch end audio and the Lch background audio. The output control unit 322 is assigned to the right side speaker 30SR and controls the output to output the Rch end audio and the Rch background audio. The output control units 321 and 322 also receive the uncorrelated components and independent components from the first separation unit 301.

[0067] The output control unit 323 is assigned to the left main speaker 30ML and controls the output to output the Lch main audio. The output control unit 324 is assigned to the right main speaker 30MR and controls the output to output the Rch main audio. The output control units 323 and 324 also receive the second independent component from the second separation unit 302.

[0068] The output control unit 325 is assigned to the left center speaker 30SCL and controls it to output Lch center audio. The output control unit 326 is assigned to the left center speaker 30SCR and controls it to output Rch center audio. The output control units 325 and 326 also receive the third independent component from the third separation unit 303. The output control unit 327 is assigned to the center speaker 30SC and controls it to output center audio. The third correlated component is also received from the third separation unit 303. Other configurations may be the same as those in the first embodiment.

[0069] In the third embodiment, an input signal input to first separation section 301 is shown in, for example, FIG. 5. A method for separating uncorrelated components and independent components by first separation section 301 is shown in, for example, FIGS. 6 and 7. Next, an example of adjustment processing by first sound image localization adjustment section 311 is shown in FIG. 9. The adjusted signal shown in FIG. 9 is output to second separation section 302.

[0070] 18 is a diagram showing an example of an input signal to the second separating section 302 according to the third embodiment. In the third embodiment, the Lch input signal i1 includes a second independent component CL2 and second correlated components CC, CL1, and CR1, and the Rch input signal ir includes a second independent component CR2 and second correlated components CC, CL1, and CR1.

[0071] The second independent component CL2 contained in the Lch input signal il is uncorrelated with the Rch input signal ir and corresponds to the left Lch main sound. The second independent component CR2 contained in the Rch input signal ir is uncorrelated with the Lch input signal il and corresponds to the right Rch main sound.

[0072] The main sound is, for example, a sound whose sound image is localized inside edge sounds whose sound images are localized at or near the left or right edges of the display 31. For example, the sound image of the left Lch main sound is localized at the position of the left main speaker 30ML. The sound image of the right Rch main sound is localized at the position of the right main speaker 30MR.

[0073] 18, the weight 1.34, which is the value multiplied by the second independent components CL2 and CR2, indicates the difference in audio output level (volume) between the left and right channels. That is, it indicates that the left Lch main audio corresponding to the second independent component CL2 is output entirely from the left channel and not from the right channel, and the right Rch main audio corresponding to the second independent component CR2 is output entirely from the right channel and not from the left channel.

[0074] The second correlation components CC, CL1, and CR1 are correlated between the Rch input signal ir and the Lch input signal il, and are components corresponding to the center sound. The weights (0.99, 0.70, and 0.41 in this example) that are multiplied by each of the second correlation components CC, CL1, and CR1 indicate the difference in sound output level between the left and right channels.

[0075] That is, it is shown that the output level from the left channel of the Lch center sound corresponding to the second correlation component CL1 is higher than the output level from the right channel, and the output level from the right channel of the Rch center sound corresponding to the second correlation component CR1 is higher than the output level from the left channel.

[0076] Based on the difference between the input signals il and ir and the target signals tl and tr, the second independent components CL2 and CR2 can be separated.

[0077] 19 is a diagram illustrating an example of a method for separating the second independent component CR2 from the difference between the Lch input signal i1 and the Lch target signal t1 to the second separating section 302 according to the third embodiment. As described above, the Lch target signal t1 is a signal obtained by subtracting the Rch input signal ir from the Lch input signal i1. As shown in FIG. 19, since both the Lch input signal i1 and the Lch target signal t1 contain the Lch second independent component CL2 and the second correlation components CL1 and CR1, the Rch second independent component CR2 contained in the Rch input signal ir can be separated by taking the difference between the Lch input signal i1 and the Lch target signal t1. The Rch second independent component CR2 is sent to the output control section 324.

[0078] 20 is a diagram showing an example of a method for separating the second independent component CL2 from the difference between the Rch input signal ir and the Rch target signal tr input to the second separating section 302 according to the third embodiment. As described above, the Rch target signal tr is a signal obtained by subtracting the Lch input signal i1 from the Rch input signal ir. As shown in FIG. 20, since both the Rch input signal ir and the Rch target signal tr contain the Rch second independent component CR2 and the second correlation components CL1 and CR1, the Lch second independent component CL2 contained in the Lch input signal i1 can be separated by taking the difference between the Rch input signal ir and the Rch target signal tr. The Lch second independent component CL2 is sent to the output control section 323.

[0079] As described above, the second separator 302 can separate the Lch second correlated components CC, CL1, and CR1 corresponding to the left channel by taking the difference between the Lch second independent component CL2 and the Lch input signal il. Also, the Rch second correlated components CC, CL1, and CR1 corresponding to the right channel can be separated by taking the difference between the Rch second independent component CR2 separated as described above and the Rch input signal ir.

[0080] Fig. 21 is a diagram showing an example of sound image localization adjustment processing by the second sound image localization adjustment unit 312 for the second correlation components CC, CL1, and CR1 according to the third embodiment. In Fig. 21, the upper part of Fig. 21 illustrates an example of a state before adjustment, and the lower part of Fig. 21 illustrates an example of a state after adjustment.

[0081] The sound image L1 of the left channel center sound is adjusted so as to be localized at the installation position of the left center speaker 30SCL. In the state before adjustment shown in the upper part of Fig. 21, the weight of the right channel of the second correlation component CL1 on the left side is a value greater than 0 (0.41 in this example), so the sound image L1 of the left channel center sound is localized inside the installation position of the left center speaker 30SCL.

[0082] Similarly, it is desired that the sound image R1 of the Rch center sound be localized at the installation position of the right center speaker 30SCR. In the state before adjustment shown in the upper part of Fig. 21, the weight of the left channel of the second correlation component CR1 on the right side is a value greater than 0 (0.41 in this example), so the sound image R1 of the Rch center sound is localized inside the installation position of the right center speaker 30SCR.

[0083] Therefore, as shown in the post-adjustment state in the lower part of Fig. 21, the weight of the right channel of the second correlation component CL1 on the left side, i.e., the output level of the right center speaker 30SCR, is set to 0, and the other weights are adjusted appropriately. This allows the sound image L1 of the Lch center sound to be localized at the installation position of the left center speaker 30SCL.

[0084] Similarly, the weight of the left channel of the second correlation component CR1 on the right side, i.e., the output level of the left center speaker 30SCL, is set to 0, and the other weights are adjusted as appropriate. This allows the sound image R1 of the Rch center sound to be localized at the installation position of the right center speaker 30SCR.

[0085] 22 is a diagram showing an example of an input signal to the third separator 303 according to the third embodiment. In the third embodiment, the Lch input signal i1 includes a third independent component CL1 and a third correlated component CC, and the Rch input signal ir includes a third independent component CR1 and a third correlated component CC.

[0086] The third independent component CL1 contained in the Lch input signal il is uncorrelated with the Rch input signal ir and corresponds to the left Lch center sound. The third independent component CR1 contained in the Rch input signal ir is uncorrelated with the Lch input signal il and corresponds to the right Rch center sound.

[0087] The center sound is, for example, a sound whose sound image is localized more inward than the main sound whose sound image is localized more inward than the left and right edges of the display 31. For example, the sound image of the left-side Lch center sound is localized at the position of the left center speaker 30SCL. The sound image of the right-side Rch center sound is localized at the position of the right center speaker 30SCR.

[0088] 22, the weight 1.40, which is the value multiplied by the third independent components CL1 and CR1, indicates the difference in audio output level (volume) between the left and right channels. That is, it indicates that the left-side Lch center audio corresponding to the third independent component CL1 is output entirely from the left channel side and not from the right channel side, and the right-side Rch center audio corresponding to the third independent component CR1 is output entirely from the right channel side and not from the left channel side.

[0089] The third correlation component CC is a component that correlates with the center audio signal and is correlated between the Rch input signal ir and the Lch input signal il. The weight (0.70 in this example) that is the value integrated into the third correlation component CC indicates the difference in audio output level between the left and right channels.

[0090] Based on the difference between the input signals il and ir and the target signals tl and tr, the third independent components CL1 and CR1 can be separated.

[0091] 23 is a diagram illustrating an example of a method for separating the third independent component CR1 from the difference between the Lch input signal i1 and the Lch target signal t1 to the third separating section 303 according to the third embodiment. As described above, the Lch target signal t1 is a signal obtained by subtracting the Rch input signal ir from the Lch input signal i1. As shown in FIG. 23, since the Lch third independent component CL1 is contained in both the Lch input signal i1 and the Lch target signal t1, the Rch third independent component CR1 contained in the Rch input signal ir can be separated by taking the difference between the Lch input signal i1 and the Lch target signal t1. The Rch third independent component CR1 is sent to the output control section 326.

[0092] 24 is a diagram illustrating an example of a method for separating the third independent component CL1 from the difference between the Rch input signal ir and the Rch target signal tr input to the third separation section 303 according to the third embodiment. As described above, the Rch target signal tr is a signal obtained by subtracting the Lch input signal i1 from the Rch input signal ir. As shown in FIG. 24, since the Rch third independent component CR1 is contained in both the Rch input signal ir and the Rch target signal tr, the Lch third independent component CL1 contained in the Lch input signal i1 can be separated by taking the difference between the Rch input signal ir and the Rch target signal tr. The Lch third independent component CL1 is sent to the output control section 325.

[0093] As described above, the third separator 303 can separate the Lch third correlated component CC corresponding to the left channel by taking the difference between the Lch third independent component CL1 and the Lch input signal il. Also, the third separator 303 can separate the Rch third correlated component CC corresponding to the right channel by taking the difference between the Rch third independent component CR1 separated as described above and the Rch input signal ir.

[0094] Then, one of the left and right channel signals of the third correlated component CC is sent to the output control unit 327. Alternatively, the left and right channel signals are added and multiplied by 0.5 to produce the third correlated component CC, which is sent to the output control unit 327. Therefore, the center sound generated from the third correlated component CC is output from the center speaker 30SC. As a result, the sound image C of the center sound is localized at the position of the center speaker 30SC.

[0095] 25 is a flowchart showing an example of processing by the DSP 21 according to the third embodiment. In step S301, the first separating unit 301 separates independent components IL and IR, uncorrelated components UL and UR, and correlated components CC, CL1, CL2, CR1, and CR2 from the input signals il and ir. That is, the first separating unit 301 separates the Lch independent component IL, the Lch uncorrelated component UL, and the Lch correlated components CC, CL1, CL2, CR1, and CR2 from the Lch input signal il, and the Rch independent component IR, the Rch uncorrelated component UR, and the Rch correlated components CC, CL1, CL2, CR1, and CR2 from the Rch input signal ir (step S301).

[0096] In step S302, the first sound image localization adjustment unit 311 performs sound field localization adjustment processing to further generate a second independent component from the Lch and Rch correlated components CC, CL1, CL2, CR1, and CR2. Specifically, the Lch correlated component CL2 is adjusted so that the output level of the R channel becomes 0, resulting in the Lch second independent component CL2. Similarly, the Rch correlated component CR2 is adjusted so that the output level of the L channel becomes 0, resulting in the Rch second independent component CR2 (step S302).

[0097] In step S303, the second separation unit 302 separates second independent components CL2 and CR2 and second correlated components CC, CL1, and CR1 from the Lch and Rch input signals i, ir from the first sound image localization adjustment unit. That is, the second separation unit 302 separates the Lch second independent component CL2 and the Lch second correlated components CC, CL1, and CR1 from the Lch input signal i, and separates the Rch second independent component CR2 and the Rch second correlated components CC, CL1, and CR1 from the Rch input signal ir (step S303).

[0098] In step S304, the second sound image localization adjustment unit 312 performs sound field localization adjustment processing to further generate a third independent component from the Lch and Rch second correlated components CC, CL1, and CR1. Specifically, the Lch second correlated component CL1 is adjusted so that the output level of the R channel becomes 0, resulting in the Lch third independent component CL1. Similarly, the Rch second correlated component CR1 is adjusted so that the output level of the L channel becomes 0, resulting in the Rch third independent component CR1 (step S304).

[0099] In step S305, the third separation unit 303 separates third independent components CL1, CR1 and third correlated component CC from the Lch and Rch input signals i, ir from the second sound image localization adjustment unit. That is, the third separation unit 303 separates the Lch third independent component CL1 and the Lch third correlated component CC from the Lch input signal i, and separates the Rch third independent component CR1 and the Rch third correlated component CC from the Rch input signal ir (step S305).

[0100] In step S306, the first separating unit 301 assigns the independent component IL and the uncorrelated component UL to the output control unit 321. The independent component IR and the uncorrelated component UR are assigned to the output control unit 322. The second separating unit 302 assigns the second independent component CL2 to the output control unit 323. The second independent component CR2 is assigned to the output control unit 324. The third separating unit 303 assigns the third independent component CL1 to the output control unit 325. The third independent component CR1 is assigned to the output control unit 326. Furthermore, the third correlated component CC is assigned to the output control unit 327 (step S306).

[0101] In step S307, the output control unit 321 controls the left side speaker 30SL to output the Lch end sound generated from the independent component IL and the Lch background sound generated from the uncorrelated component UL. Similarly, the output control unit 322 controls the right side speaker 30SR to output the Rch end sound generated from the independent component IR and the Rch background sound generated from the uncorrelated component UR.

[0102] The output control unit 323 also controls the left main speaker 30ML to output the Lch main sound generated from the second independent component CL2. Similarly, the output control unit 324 controls the right main speaker 30MR to output the Rch main sound generated from the second independent component CR2.

[0103] Furthermore, the output control unit 325 controls the left center speaker 30SCL to output the Lch center sound generated from the third independent component CL1. Similarly, the output control unit 326 controls the right center speaker 30SCR to output the Rch center sound generated from the third independent component CR1. The output control unit 327 controls the center sound generated from the third correlated component CC to output from the center speaker 30SC (step S307).

[0104] As a result, the left sound image LL of the end sound is localized at the installation position of the left side speaker 30SL, and the right sound image RR of the end sound is localized at the installation position of the right side speaker 30SR. Also, the sound image UU of the background sound is localized so as to spread in the space between the installation positions of the left side speaker 30SL and the right side speaker 30SR.

[0105] Furthermore, the sound image L2 of the Lch main sound is localized at the installation position of the left main speaker 30ML, and the sound image R2 of the Rch main sound is localized at the installation position of the right main speaker 30MR.

[0106] Furthermore, the sound image L1 of the Lch center sound is localized at the installation position of the left center speaker 30SCL, the sound image R1 of the Rch center sound is localized at the installation position of the right center speaker 30SCR, and the sound image C of the center sound is localized at the installation position of the center speaker 30SC.

[0107] As described above, according to this embodiment, the left and right input signals are separated into independent components, uncorrelated components, and correlated components to be assigned to each speaker. Furthermore, the correlated components are further separated into second independent components and second correlated components. This allows background audio generated from the uncorrelated components and edge audio generated from the independent components to be assigned to the left and right speakers and output. Furthermore, audio composed of correlated components can be assigned to the center speaker and output. This allows sound images localized at each speaker to be generated, preventing the sound images from overlapping with each other. As a result, audio degradation and a decrease in the sense of realism can be suppressed. Furthermore, by generating independent components using the first and second separation units, sound images independent of the independent components can be formed from each speaker.

[0108] Furthermore, by separating the sound into independent components and correlated components using the third separation unit, it is possible to assign sound made up of independent components to each speaker. Specifically, it is possible to assign sound made up of independent components to the left side speaker, right side speaker, left main speaker, right main speaker, left center speaker, and right center speaker, respectively. This makes it possible to form an independent sound image from each speaker, and to output high-quality sound with a high sense of presence.

[0109] (Fourth embodiment) 26 is a diagram showing an example of the configuration of multiple speakers of a display device 1 according to a fourth embodiment. This embodiment shows a configuration in which one center speaker is removed from the speakers of the third embodiment. The display device 1 of this embodiment includes a left main speaker 40ML (an example of a first left speaker), a right main speaker 40MR (an example of a first right speaker), a left side speaker 40SL (an example of a second left speaker), and a right side speaker 40SR (an example of a second right speaker), as well as a left center speaker 40SCL (an example of a third left speaker) and a right center speaker 40SCR (an example of a third right speaker).

[0110] 27 is a diagram showing an example of the functional configuration of a DSP 21 according to the fourth embodiment. The DSP 21 of the fourth embodiment includes separation units 401 and 402, sound image localization adjustment units 411 and 412, and output control units 421 to 426. The third separation unit 403 and the output control unit assigned to the center speaker of the third embodiment are omitted.

[0111] The processing of the first separation unit 401, the second separation unit 402, the first sound image localization adjustment unit 411, and the second sound image localization adjustment unit 412 is the same as in the third embodiment. Note that configurations not described in the fourth embodiment are omitted because they are the same as in the third embodiment.

[0112] The third correlated component and the third independent component of the Lch output signal and the Rch output signal, which are the audio signals output from the second sound image localization adjustment section 412, are sent to the output control sections 425 and 426.

[0113] In the fourth embodiment, since there is no speaker to be assigned to the third correlation component, the left and right channel signals of the third correlation component are assigned to the left center speaker 40SCL and the right center speaker 40SCR, respectively, which allows the third correlation component to localize a sound image between the left center speaker 40SCL and the right center speaker 40SCR.

[0114] The audio device of the present embodiment is provided in a display device such as a television, for example, as an example, but the functions of the audio device of the present invention may also be provided in a speaker that is connected to a television for use.

[0115] A program for realizing the functions of the display device 1 (DSP21) described above may be provided by being recorded in a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a digital versatile disk (DVD) in the form of a file that can be installed or executed by a computer. Alternatively, the program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Alternatively, the program may be provided or distributed via a network such as the Internet.

[0116] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0117] 1...display device, 21...DSP (audio device), 23ML...left main speaker (first left speaker), 23MR...right main speaker (first right speaker), 23SL...left side speaker (second left speaker), 23SR...right side speaker (second right speaker), 101...separation unit, 102...sound image localization adjustment unit, 103...output control unit, 201, 201R...adaptive filter (filter unit), 211L, 211R...adaptive algorithm (coefficient update unit), C, L1, L2, LL, R1, R2, RR, UU...sound image

Claims

1. An audio device that performs processing to output audio from multiple speakers, a separation unit that separates, from each of a left input signal corresponding to the left channel and a right input signal corresponding to the right channel, into a sum of the independent components and the uncorrelated components, and the correlated components: an independent component corresponding to end sound that has no correlation between the left channel and the right channel and whose sound image is localized at the left end or the right end of a predetermined region; an uncorrelated component corresponding to background sound that has no correlation between the left channel and the right channel and whose sound image range is wider than the end sound; and a correlated component corresponding to intermediate sound that has a correlation between the left channel and the right channel and whose sound image is localized inside the localization positions of the sound images of the left and right end sounds; a sound image localization adjustment unit that adjusts at least one of the correlated components and the independent components so that left and right sound images of the end sound generated from the independent components are localized at the left and right ends of the predetermined area, and a sound image of the intermediate sound generated from the correlated components is localized between the localization positions of the left and right sound images of the end sound; an output control unit that outputs the end audio, the background audio, and the intermediate audio from the plurality of speakers, the plurality of speakers include a first left speaker and a first right speaker disposed to the right of the first left speaker, the output control unit outputs the end sound, the background sound, and the intermediate sound from the first left speaker and the first right speaker; the sound image localization adjustment unit adjusts the independent components so that a left sound image of the end sound is localized to the left of an installation position of the first left speaker and a right sound image of the end sound is localized to the right of an installation position of the first right speaker, and adjusts the correlated components so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker. Audio equipment.

2. the plurality of speakers include the first left speaker, the first right speaker, a second left speaker disposed to the left of the first left speaker, and a second right speaker disposed to the right of the first right speaker; the output control unit outputs the intermediate sound from the first left speaker and the first right speaker, and outputs the end sound and the background sound from the second left speaker and the second right speaker; the sound image localization adjustment unit adjusts the independent components so that a left sound image of the end sound is localized at an installation position of the second left speaker and a right sound image of the end sound is localized at an installation position of the second right speaker, and adjusts the correlated components so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker.

10. The audio device of claim 1.

3. the sound image localization adjustment unit adjusts the uncorrelated components so that the left end of the sound image of the background sound reaches the left side of the installation position of the first left speaker and the right end of the sound image reaches the right side of the installation position of the first right speaker.

10. The audio device of claim 1.

4. the separation unit includes: a filter unit that applies a finite impulse response based on predetermined coefficients to the left input signal and the right input signal, and outputs an output signal corresponding to a component correlated with a target signal based on a difference between the left input signal and the right input signal; and a coefficient update unit that updates the coefficients so that a value of an error signal based on the difference between the target signal and the output signal is minimized.

4. The audio device according to claim 1.

5. An audio control method for outputting audio from a plurality of speakers, comprising: a step of separating, from each of a left input signal corresponding to the left channel and a right input signal corresponding to the right channel, an independent component corresponding to end sound that has no correlation between the left channel and the right channel and whose sound image is localized at the left end or the right end of a predetermined region, an uncorrelated component corresponding to background sound that has no correlation between the left channel and the right channel and whose sound image range is wider than the end sound, and a correlated component corresponding to intermediate sound that has a correlation between the left channel and the right channel and whose sound image is localized inside the localization positions of the sound images of the left and right end sounds, into a sum of the independent component and the uncorrelated component and the correlated component; adjusting at least one of the correlated component and the independent component so that left and right sound images of the end sound generated from the independent component are localized at the left and right ends of the predetermined area, and a sound image of the intermediate sound generated from the correlated component is localized between the localization positions of the left and right sound images of the end sound; outputting the end sound, the background sound, and the intermediate sound from the plurality of speakers; the plurality of speakers include a first left speaker and a first right speaker disposed to the right of the first left speaker, the outputting step includes outputting the end sound, the background sound, and the intermediate sound from the first left speaker and the first right speaker; the adjusting step adjusts the independent components so that a left sound image of the end sound is localized to the left of an installation position of the first left speaker and a right sound image of the end sound is localized to the right of an installation position of the first right speaker, and adjusts the correlated components so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker. Audio control methods.

6. An information processing device that performs processing to output audio from multiple speakers, a process of separating, from each of a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component corresponding to end sound that has no correlation between the left channel and the right channel and whose sound image is localized at the left end or the right end of a predetermined region, an uncorrelated component corresponding to background sound that has no correlation between the left channel and the right channel and whose sound image range is wider than the end sound, and a correlated component corresponding to intermediate sound that has a correlation between the left channel and the right channel and whose sound image is localized inside the localization positions of the sound images of the left and right end sounds, into a sum of the independent component and the uncorrelated component and the correlated component; a process of adjusting at least one of the correlated components and the independent components so that left and right sound images of the end sound generated from the independent components are localized at the left and right ends of the predetermined area, and a sound image of the intermediate sound generated from the correlated components is localized between the localization positions of the left and right sound images of the end sound; outputting the edge audio, the background audio, and the intermediate audio from the plurality of speakers; the plurality of speakers include a first left speaker and a first right speaker disposed to the right of the first left speaker, the outputting process includes outputting the end sound, the background sound, and the intermediate sound from the first left speaker and the first right speaker; The adjustment process includes adjusting the independent components so that a left sound image of the end sound is localized to the left of an installation position of the first left speaker and a right sound image of the end sound is localized to the right of an installation position of the first right speaker, and adjusting the correlated components so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker. program.

7. a first separation unit that separates, from each of a left input signal corresponding to the left channel and a right input signal corresponding to the right channel, an independent component that has no correlation between the left channel and the right channel and localizes a sound image by one of the channels, an uncorrelated component that has no correlation between the left channel and the right channel and corresponds to a background sound in a wider range than the sound image of the independent component, and a correlated component that has a correlation between the left channel and the right channel and localizes a sound image inward from the sound image of the independent component by the left channel and the right channel, into a sum of the independent component and the uncorrelated component and the correlated component; a first sound image localization adjustment unit that adjusts the correlated components to a second independent component that is generated on the left side by the left channel and on the right side by the right channel, and a second correlated component whose sound image is localized more inward than the sound image of the second independent component; a second separation unit that separates the adjusted second independent component and the adjusted second correlated component into the second independent component and the second correlated component; an output control unit that controls the components output from the first separation unit and the second separation unit to be output from a plurality of speakers; the plurality of speakers include a first left speaker and a first right speaker disposed to the right of the first left speaker, the output control unit outputs, from the first left speaker and the first right speaker, an end sound whose sound image is localized by the one channel, the background sound, and an intermediate sound whose sound image is localized inside the sound image of the independent component; the first sound image localization adjustment unit adjusts the independent components so that a left sound image of the end sound is localized to the left of an installation position of the first left speaker and a right sound image of the end sound is localized to the right of an installation position of the first right speaker, and adjusts the second independent component and the second correlated component so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker. Audio equipment.

8. a second sound image localization adjustment unit that adjusts the second correlated component to a third independent component that is generated on the left side by the left channel and on the right side by the right channel, and a third correlated component whose sound image is localized more inward than the sound image of the third independent component; a third separation unit that separates the adjusted third independent component and the adjusted third correlated component into the third independent component and the third correlated component; the output control unit controls the components output from the first separation unit, the second separation unit, and the third separation unit to be output from the plurality of speakers.

8. An audio device according to claim 7.

9. An audio control method for outputting audio from a plurality of speakers, comprising: a first separation step of separating, from each of a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component that is not correlated between the left channel and the right channel and that localizes a sound image by one of the channels, an uncorrelated component that is not correlated between the left channel and the right channel and corresponds to a background sound in a wider range than the sound image of the independent component, and a correlated component that is correlated between the left channel and the right channel and that localizes a sound image inward from the sound image of the independent component by the left channel and the right channel; adjusting the correlated components to a second independent component generated on the left side by the left channel and on the right side by the right channel, and a second correlated component whose sound image is localized more inward than the sound image of the second independent component; a second separation step of separating the adjusted second independent component and the adjusted second correlated component into the second independent component and the second correlated component; an output control step of controlling the components output from the first separation step and the second separation step so that the components are output from the plurality of speakers; the plurality of speakers include a first left speaker and a first right speaker disposed to the right of the first left speaker, the output control step includes outputting, from the first left speaker and the first right speaker, an end sound whose sound image is localized by the one channel, the background sound, and an intermediate sound whose sound image is localized inside the sound image of the independent component; the adjusting step adjusts the independent components so that a left sound image of the end sound is localized to the left of an installation position of the first left speaker and a right sound image of the end sound is localized to the right of an installation position of the first right speaker, and adjusts the second independent component and the second correlated component so that a left edge sound image of the intermediate sound is localized at an installation position of the first left speaker and a right edge sound image of the intermediate sound is localized at an installation position of the first right speaker. Audio control methods.

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