Audio device, audio control method, and nonvolatile storage medium

Abstract

The present application relates to an audio device, an audio control method, and a nonvolatile storage medium. The audio device comprises a separation unit and a sound image positioning adjustment unit; the separation unit separates independent components, unassociated components, and associated components on the basis of a left input signal and a right input signal; the independent components have no association between a left sound channel and a right sound channel, and correspond to end sounds of which sound images are positioned at the left end or the right end of a specified area; the unassociated components have no association between the left sound channel and the right sound channel, and correspond to background sounds having sound image ranges broader than the end sounds; the associated components have an association between the left sound channel and the right sound channel, and correspond to intermediate sounds of which sound images are positioned closer to the inner side than the sound images of the left end sound and the right end sound; and the sound image positioning adjustment unit adjusts at least one of the associated components and the independent components, so that a left sound image and a right sound image of the end sounds generated on the basis of the independent components are positioned at the left end and the right end of the specified area, and the sound images of the intermediate sounds generated on the basis of the associated components are positioned between the positioning positions of the left sound image and the right sound image of the end sounds.

Description

Audio device, audio control method, and non-volatile storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Japanese patent application No. 2024-055239, filed with the Japan Patent Office on March 29, 2024, and entitled “Audio Device, Audio Control Method, and Program,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to an audio device, an audio control method and a non-volatile storage medium. Background Art

[0004] In a device that outputs sound, the following sound image localization technology is used: a correlated component (correlated between channels) and an uncorrelated component (uncorrelated between channels) are separated from a two-channel stereo signal, and these correlated and uncorrelated components are used to make the user feel the position of a virtual sound source.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-333698. Summary of the Invention

[0008] In display devices such as televisions, when it is desired to achieve sound image localization based on the sound output from multiple built-in speakers, previous sound image localization technologies sometimes cause multiple sound images that should have been separated to overlap, resulting in sound degradation and a lack of immersiveness.

[0009] The problem to be solved by the embodiments of the present application is to provide an audio device, an audio control method, and a program that can form high-quality sound and images.

[0010] An embodiment of the present application is an audio device that performs processing for outputting sound from a plurality of speakers, the audio device comprising a separation unit, a sound image localization adjustment unit, and an output control unit, the separation unit separating an independent component, an uncorrelated component, and a correlated component based on a left input signal corresponding to the left channel and a right input signal corresponding to the right channel, respectively. The independent component has no correlation between the left channel and the right channel and corresponds to an end sound whose sound image is localized at the left end or the right end of a specified area, and the uncorrelated component has no correlation between the left channel and the right channel and corresponds to a sound image having a range wider than that of the end sound. The associated component corresponds to the background sound, the associated component is associated between the left channel and the right channel, and corresponds to the middle sound whose sound image is positioned inside than the localization position of the sound image of the left and right end sounds, the sound image localization adjustment unit adjusts at least one of the associated component and the independent component so that the left and right sound images of the end sounds generated according to the independent component are localized at the left and right ends of the specified area, and the sound image of the middle sound generated according to the associated component is localized between the localization positions of the left and right sound images of the end sounds, and the output control unit causes the end sounds, background sounds and middle sounds to be output from multiple speakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 1 is a diagram showing an example of a hardware configuration of a display device according to a first embodiment;

[0012] FIG2 is a diagram showing an example of the structure of a plurality of speakers according to the first embodiment;

[0013] 3 is a diagram showing an example of a functional configuration of a DSP according to the first embodiment;

[0014] 4 is a diagram showing an example of the structure of a separation unit according to the first embodiment;

[0015] 5 is a diagram showing an example of components included in an input signal according to the first embodiment;

[0016] 6 is a diagram showing an example of a method of separating independent components and uncorrelated components based on the difference between an Lch input signal and an Lch target signal according to the first embodiment;

[0017] 7 is a diagram showing an example of a method of separating independent components and uncorrelated components based on the difference between the Rch input signal and the Rch target signal according to the first embodiment;

[0018] 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;

[0019] 9 is a diagram showing an example of the sound image localization adjustment process for the correlation component according to the first embodiment;

[0020] 10 is a flowchart showing an example of processing performed by the DSP in the first embodiment;

[0021] FIG11 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the second embodiment;

[0022] FIG12 is a diagram showing an example of a functional configuration of a DSP according to a second embodiment;

[0023] 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;

[0024] 14 is a diagram showing an example of sound image localization adjustment processing for independent components and uncorrelated components according to the second embodiment;

[0025] 15 is a flowchart showing an example of processing performed by the DSP according to the second embodiment;

[0026] FIG16 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the third embodiment;

[0027] FIG17 is a diagram showing an example of a functional configuration of a DSP according to a third embodiment;

[0028] 18 is a diagram showing an example of an input signal to a second separation unit according to the third embodiment;

[0029] 19 is a diagram showing an example of a method of separating independent components based on the difference between an Lch input signal and an Lch target signal according to the third embodiment;

[0030] 20 is a diagram showing an example of a method of separating independent components based on the difference between the Rch input signal and the Rch target signal according to the third embodiment;

[0031] 21 is a diagram showing an example of sound image localization adjustment processing for correlated components according to the third embodiment;

[0032] FIG22 is a diagram showing an example of components included in an input signal according to the third embodiment;

[0033] 23 is a diagram showing an example of a method of separating independent components based on the difference between an Lch input signal and an Lch target signal according to the third embodiment;

[0034] 24 is a diagram showing an example of a method of separating independent components based on the difference between an Rch input signal and an Rch target signal according to the third embodiment;

[0035] 25 is a flowchart showing an example of processing performed by the DSP in the third embodiment;

[0036] FIG26 is a diagram showing an example of the configuration of a plurality of speakers of the display device 1 according to the fourth embodiment;

[0037] FIG. 27 is a diagram showing an example of a functional configuration of a DSP according to the fourth embodiment.

[0038] Explanation of the reference numerals 1…display device, 21…DSP (audio device), 23ML…left main speaker (first left speaker), 23MR…right main speaker (first right speaker), 23SL…left speaker (second left speaker), 23SR…right speaker (second right speaker), 101…separation unit, 102…sound image localization adjustment unit, 103…output control unit, 201, 201R…adaptive filter (filtering unit), 211L, 211R…adaptive algorithm (coefficient updating unit), C, L1, L2, LL, R1, R2, RR, UU…sound image. DETAILED DESCRIPTION

[0039] Illustrative embodiments of the present application are disclosed below.

[0040] First embodiment

[0041] FIG1 is a diagram illustrating an example of the hardware configuration of a display device 1 according to a first embodiment. Display device 1 is a device capable of displaying images and outputting audio, and may be, for example, a television. The display device 1 illustrated here includes a processor 11, memory 12, a UI (User Interface) 13, peripheral circuits 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.

[0042] The processor 11 performs predetermined calculations and control processes according to programs stored in the memory 12. The memory 12 includes primary storage devices such as RAM (Random Access Memory) and ROM (Read Only Memory), as well as secondary storage devices such as SSDs (Solid State Drives) and HDDs (Hard Disk Drives), and stores programs and various data necessary to implement the functions of the display device 1. The UI 13 is a unit that receives user operations. The peripheral circuits 14 are circuits that assist the operations of the processor 11 and may include, for example, a power supply circuit, an oscillator circuit, and a reset circuit.

[0043] 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 decrypts encrypted audio signals. The audio input ADC 17 is a device that converts analog audio signals into digital signals.

[0044] The DSP 21 is an information processing device that performs predetermined processing on audio signals received from the communication circuit 15, audio decoder 16, or audio input ADC 17. The DSP 21 can be configured using, for example, a CPU (Central Processing Unit), memory, and input / output interfaces. The DSP 21 of this embodiment optimizes the audio output from the multiple speakers 23 built into the display device 1 so that the audio output forms a predetermined sound image. The audio signals processed by the DSP 21 are output to each speaker 23 via the amplifier 22.

[0045] Fig. 2 is a diagram showing an example of the configuration of the plurality of speakers 23 according to the first embodiment. Fig. 2 illustrates a state where the display device 1 is viewed from the front side of the display 31.

[0046] As shown in FIG2 , 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 speaker 23SL (an example of a second left speaker), and a right speaker 23SR (an example of a second right speaker). The left main speaker 23ML is located near the left end of the lower portion of the display device 1 (display 31). The right main speaker 23MR is located near the right end of the lower portion of the display device 1. The left speaker 23SL is located on the left side of the display device 1 and is located to the left of the left main speaker 23ML. The right speaker 23SR is located on the right side of the display device 1 and is located to the right of the right main speaker 23MR.

[0047] It should be noted that the arrangement of the left main speaker 23ML, the right main speaker 23MR, the left speaker 23SL, and the right speaker 23SR is an example and is not limited to the above.

[0048] FIG3 is a diagram illustrating an example of the functional configuration of the DSP 21 according to the first embodiment. The DSP 21 according to this embodiment includes a separation unit 101, a sound image localization adjustment unit 102, and an output control unit 103. These functional units are implemented through the collaboration of the hardware and software that comprise the DSP 21. Alternatively, at least one of these functional units may be implemented as dedicated hardware (e.g., circuitry).

[0049] The separation unit 101 separates independent components, uncorrelated components, and correlated components from the Lch input signal and the Rch input signal, which are audio signals input to the DSP 21. The Lch input signal corresponds to the left channel in two-channel stereo playback, and the Rch input signal corresponds to the right channel in the stereo playback.

[0050] Independent components are components that have no correlation between the left and right channels and correspond to edge sounds whose sound images are localized at the left or right end of the display 31 (an example of a predetermined area). Uncorrelated components are components that have no correlation between the left and right channels and correspond to background sounds whose sound images are wider than those of the edge sounds. Correlated components are components that have a correlation between the left and right channels and correspond to intermediate sounds whose sound images are localized further inward than the localized positions of the edge sounds.

[0051] The sound image localization adjustment unit 102 performs sound image localization adjustment processing to localize the sound images output from the plurality of speakers 23 (in this embodiment, the left main speaker 23ML, the right main speaker 23MR, the left speaker 23SL, and the right main speaker 23MR) at appropriate locations. The sound image localization adjustment processing in this embodiment includes adjusting at least one of the correlated components and the independent components so that the left and right sound images of the end sounds are localized at the left and right ends of the display 31 (display device 1), and the sound image of the middle sound is localized between the left and right localized positions of the end sound images.

[0052] The output control unit 103 causes the end sound generated based on the independent components, the background sound generated based on the uncorrelated components, and the middle sound generated based on the middle components to be output from the corresponding speakers 23, respectively. In this embodiment, the Lch end sound generated based on the independent components separated from the Lch input signal and the Lch background sound generated based on the uncorrelated components separated from the Lch input signal are output from the left speaker 23SL. The Rch end sound generated based on the independent components separated from the Rch input signal and the Rch background sound generated based on the uncorrelated components separated from the Rch input signal are output from the right speaker 23SR. The Lch middle sound generated based on the correlated components separated from the Lch input signal is output from the left main speaker 23ML. The Rch middle sound generated based on the correlated components separated from the Rch input signal is output from the right main speaker 23MR.

[0053] 4 is a diagram showing an example of the configuration of the separation unit 101 according to the first embodiment. The separation unit 101 shown here includes adaptive filters 201L and 201R (an example of a filtering unit) and adaptive algorithms 211L and 211R (an example of a coefficient updating unit).

[0054] Adaptive filters 201L and 201R apply finite impulse responses (FIRs) based on predetermined coefficients xl0 to xl7 and xr0 to xr7 to the left and right input signals il and ir, respectively, to output output signals ol and or. Specifically, the Lch adaptive filter 201L corresponding to the left channel applies a FIR based on coefficients xl0 to xl7 to the Lch input signal il, thereby outputting the output signal ol contained in the Lch input signal. The Rch adaptive filter 201R corresponding to the right channel applies a FIR based on coefficients xr0 to xr7 to the Rch input signal ir, thereby outputting the output signal or contained in the Rch input signal. It should be noted that while the FIR has an 8-tap number as an example, this is not a limitation.

[0055] Adaptive algorithms 211L and 211R are used to optimize the coefficients xl0 to xl7 and xr0 to xr7 of adaptive filters 201L and 201R. Adaptive algorithms 211L and 211R update the coefficients xl(n) and xr(n) to minimize the error signal values ​​el(n) and er(n). These error signal values ​​el(n) and er(n) are based on the difference between 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, which are output from adaptive filters 201L and 201R. In this example, n corresponds to the number of taps (8) in adaptive filters 201L and 201R and is a value between 0 and 7. The Lch adaptive algorithm 211L for the left channel updates the coefficients xl(n) to minimize the error signal value el(n), which is the difference between the target signal tl (the difference (il - ir) between the Lch input signal il and the Rch input signal ir) multiplied by a predetermined weight gl, and the output signal ol output from the Lch adaptive filter 201L. The Rch adaptive algorithm 211R for the right channel updates the coefficients xr(n) to minimize the error signal value er(n), which is the difference between the target signal tr (the difference (ir - il) between the Rch input signal ir and the Lch input signal il) multiplied by a predetermined weight gr, and the output signal or output from the Rch adaptive filter 201R.

[0056] Adaptive filters 201L and 201R, whose coefficients xl0 to xl7 and xr0 to xr7 are optimized by the adaptive algorithms 211L and 211R described above, separate the independent and uncorrelated components corresponding to the error signals el(n) and er(n) from the input signals il and ir. The independent and uncorrelated components are then subtracted from the input signals to separate the correlated components. Furthermore, the above-described configuration eliminates the need for filtering (eliminating) the uncorrelated components by adaptive filters 201L and 201R, reduces the sharp changes in the filter's frequency characteristics, and suppresses the occurrence of components that cause abnormal sounds.

[0057] FIG5 is a diagram showing an example of components included in input signals il and ir according to the first embodiment. In this example, the Lch input signal il 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.

[0058] The uncorrelated component UL included in the Lch input signal i1 is uncorrelated with the Rch input signal i1 and corresponds to background sound. The uncorrelated component UR included in the Rch input signal i1 is uncorrelated with the Lch input signal i1 and corresponds to background sound. Background sound is, for example, sound whose sound image is localized so as to propagate across the entire left and right area of ​​the display 31.

[0059] The independent component IL included in the Lch input signal il is a component that is unrelated to the Rch input signal ir and corresponds to the end sound on the left side. The independent component IR included in the Rch input signal ir is a component that is unrelated to the Lch input signal il and corresponds to the end sound on the right side. End sounds are, for example, sounds whose sound images are localized at or near the left or right ends of the display 31. For example, the sound image of the end sound on the left side is localized at the left end of the display 31, and the sound image of the end sound on the right side is localized at the right end of the display 31. In Figure 5, the value obtained by multiplying the independent components IL and IR, that is, the weight 1.0, represents the difference in output level (volume) of the sound between the left and right channels. In other words, it represents the following situation: the end sound on the left side corresponding to the independent component IL is output entirely from the left channel side and not from the right channel side, and the end sound on the right side corresponding to the independent component IR is output entirely from the right channel side and not from the left channel side.

[0060] Correlated components CC, CL1, CL2, CR1, and CR2 are components that are correlated between the Rch input signal ir and the Lch input signal il and correspond to the center sound. For example, a center sound is a sound whose sound image is localized inward of the localized positions of the left and right sound images of the end sounds. Correlated component CC corresponds to a sound whose sound image is localized in the center of the sound image range to the left of the center within the sound image range. Correlated component CL1 corresponds to a sound whose sound image is localized to the left of the center within the sound image range. Correlated component CL2 corresponds to a sound whose sound image is localized to the left of the localized position of the sound of correlation component CL1 and to the right of the localized position of the sound image to the left of the end sounds within the sound image range. Correlated component CR1 corresponds to a sound whose sound image is localized to the right of the center within the sound image range. Correlated component CR2 corresponds to a sound whose sound image is localized to the right of the localized position of the sound of correlation component CR1 and to the left of the localized position of the sound image to the right of the end sounds within the sound image range.

[0061] In Figure 5, the values ​​obtained by multiplying the associated components CC, CL1, CL2, CR1, and CR2, i.e., the weights (0.90, 0.80, 0.70, 0.60, and 0.44 in this example), respectively, represent the output level difference of the sound between the left and right channels. That is, it indicates that the output level of the intermediate sound corresponding to the associated components CL1 and CL2 from the left channel is greater than the output level from the right channel. In addition, it indicates that the output level difference between the left and right channels in the associated component CL2 is greater than the output level difference between the left and right channels in the associated component CL1. The same applies to the associated components CR1 and CR2. It should be noted that the weights illustrated here are set to Wl when the weight in the left channel is set to Wl and the weight in the right channel is set to Wr. 2 +Wr 2 is 1 or approximately 1. For example, the weight of the correlation component CL1 is 0.90. 2 +0.44 2 ≈1.0, the weight of the associated component CL2 is 0.80 2 +0.64 2 = 1.0. The same applies to the correlation components CR1 and CR2.

[0062] Based on the differences between the input signals il, ir and the target signals tl, tr as described above, the independent components IL, IR and the uncorrelated components UL, UR can be separated.

[0063] FIG6 illustrates an example of a method for separating independent components IR and uncorrelated components UR based on the difference between the Lch input signal i1 and the Lch target signal t1 according to the first embodiment. As described above, the Lch target signal t1 is the signal obtained by subtracting the Rch input signal ir from the Lch input signal i1. As shown in FIG6 , because both the Lch input signal i1 and the Lch target signal t1 contain the Lch independent component IL, the Lch uncorrelated component UL, and the correlated components CL1, CL2, CR1, and CR2, the Rch independent component IR and the Rch uncorrelated component UR 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.

[0064] FIG7 illustrates an example of a method for separating independent components IL and uncorrelated components UL based on the difference between the Rch input signal ir and the Rch target signal tr according to the first embodiment. As described above, the Rch target signal tr is the signal obtained by subtracting the Lch input signal il from the Rch input signal ir. As shown in FIG7 , because both the Rch input signal ir and the Rch target signal tr contain the Rch independent component IR, the Rch uncorrelated component UR, and the 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.

[0065] Furthermore, by obtaining the difference between the Lch independent component IL and the Lch uncorrelated component UL separated as described above 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 obtaining the difference between the Rch independent component IR and the Rch uncorrelated component UR separated as described above and the Rch input signal ir, the Rch-correlated components CC, CL1, CL2, CR1, and CR2 corresponding to the right channel can be separated.

[0066] FIG8 is a diagram illustrating an example of the relationship between the output locations of various sounds and their sound images in the first embodiment. In FIG8 , sound image LL shows the sound image on the left side of the end sound, and sound image RR shows the sound image on the right side of the end sound. Sound image UU shows the sound image of the background sound. Sound images C, L1, L2, R1, and R2 show the sound image of the intermediate sound.

[0067] The output control unit 103 of this embodiment outputs the Lch end sound generated based on the Lch independent component IL from the left speaker 23SL, and the Rch end sound generated based on the Rch independent component IR from the right speaker 23SR. This allows the left sound image LL of the end sound to be localized at the installation position of the left speaker 23SL, and the right sound image RR of the end sound to be localized at the installation position of the right speaker 23SR.

[0068] Furthermore, the output control unit 103 causes the left speaker 23SL to output the Lch background sound generated based on the Lch uncorrelated component UL, and causes the right speaker 23SR to output the Rch background sound generated based on the Rch uncorrelated component UR. This allows the sound image UU of the background sound to be localized so that it propagates in the space between the installation positions of the left speaker 23SL and the installation position of the right speaker 23SR.

[0069] Furthermore, the output control unit 103 causes the left main speaker 23ML to output the Lch middle sound generated based on the Lch-related components CC, CL1, CL2, CR1, and CR2, and causes the right main speaker 23MR to output the Rch middle sound generated based on the Rch-related components CC, CL1, CL2, CR1, and CR2. This allows the sound images C, L1, L2, R1, and R2 of the middle sound to be localized between the localized positions of the sound images LL and RR of the left and right end sounds.

[0070] At this time, the sound image localization adjustment unit 102 of this embodiment adjusts the left and right weights of the associated components CC, CL1, CL2, CR1, and CR2 so that the sound image L2 at the left end of the middle sound is positioned at the setting position of the left main speaker 23ML, and the sound image R2 at the right end is positioned at the setting position of the right main speaker 23MR.

[0071] FIG9 is a diagram showing an example of the sound image localization adjustment processing for the associated components CC, CL1, CL2, CR1, and CR2 according to the first embodiment. In FIG9 , the state before adjustment is illustrated in the upper portion, and the state after adjustment is illustrated in the lower portion. In the state before adjustment, because the weight of the right channel of the associated component CL2 at the left end is a value greater than 0 (0.44 in this example), the sound image L2 at the left end of the center sound is positioned at a position further inward than the setting position of the left main speaker 23ML. Similarly, because the weight of the left channel of the associated component CR2 at the right end is a value greater than 0 (0.44 in this example), the sound image R2 at the right end of the center sound is positioned at a position further inward than the setting position of the right main speaker 23MR.

[0072] Here, as shown in the table at the bottom of FIG9 , by setting the right channel weight of the left-most correlated component CL2, that is, the output level from the right main speaker 23MR, to 0 and adjusting the other weights as appropriate, the left-most sound image L2 of the center sound can be localized at the installation position of the left main speaker 23ML. Similarly, by setting the left channel weight of the right-most correlated component CR2, that is, the output level from the left main speaker 23ML, to 0 and adjusting the other weights as appropriate, the right-most sound image R2 of the center sound can be localized at the installation position of the right main speaker 23MR.

[0073] FIG10 is a flowchart illustrating an example of processing performed by the DSP 21 according to the first embodiment. In step S101, the separation unit 101 separates the independent components IL, IR, the uncorrelated components UL, UR, and the correlated components CC, CL1, CL2, CR1, and CR2 from the input signals il and ir. Specifically, the Lch independent component IL, the Lch uncorrelated component UL, and the Lch correlated components CC, CL1, CL2, CR1, and CR2 are separated 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 are separated from the Rch input signal ir.

[0074] In step S102, the sound image localization adjustment unit 102 performs sound image localization adjustment processing on the independent components and the correlated components so that the left and right sound images LL and RR of the end sound are respectively localized at the installation positions of the left and right speakers 23SL and 23R (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 center sound are localized between the localization positions of the left and right sound images LL and RR of the end sound. 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. In addition, as shown in FIG9 , the correlated components CC, CL1, CL2, CR1, and CR2 are adjusted so that the output level of the R channel of the left component is 0 and the output level of the L channel of the right component is 0.

[0075] In step S103, the output control unit 103 causes the side speakers 23SL and 23SR to output the end sound generated from the independent components and the background sound generated from the uncorrelated components. This causes the left-side sound image LL of the end sound to be localized at the location of the left speaker 23SL, and the right-side sound image RR of the end sound to be localized at the location of the right speaker 23SR. Furthermore, the sound image UU of the background sound is localized so that it propagates in the space between the locations of the left and right speakers 23SL and 23SR.

[0076] Furthermore, in step S104, the output control unit 103 causes the main speakers 23ML and 23MR to output the intermediate sound generated based on the correlation components. This causes the sound images C, L1, L2, R1, and R2 of the intermediate sound to be localized between the left and right sound images LL and RR of the end sounds. It should be noted that steps S103 and S104 are actually executed in parallel.

[0077] As described above, according to this embodiment, the input signal is separated into independent, uncorrelated, and correlated components. The center sound generated based on the correlated components is output from the main speakers 23ML and 23MR, while the end sounds generated based on the independent components are output from the side speakers 23SL and 23SR, which are positioned outboard of the main speakers 23ML and 23MR. This allows the sound images LL and RR of the end sounds to be localized at the ends of the display 31, ensuring a wide area for localizing the sound images C, L1, L2, R1, and R2 of the center sounds. This prevents sound degradation and reduced immersiveness caused by overlapping the sound images C, L1, L2, R1, and R2 of the center sounds and the sound images LL and RR of the end sounds. Furthermore, by outputting the background sound generated based on the uncorrelated components from the side speakers 23SL and 23SR, the background sound image UU can be localized so that it spreads across the entire left and right area of ​​the display 31. This allows for the formation of a high-quality sound image and the output of high-quality sound with a strong sense of immersiveness.

[0078] Hereinafter, other embodiments will be described with reference to the drawings. However, description of the same or similar parts as those of the first embodiment will be appropriately omitted.

[0079] Second embodiment

[0080] FIG11 illustrates an example configuration of multiple speakers 23 in a display device 1 according to a second embodiment. In this embodiment, the side speakers 23SL and 23SR of the first embodiment are not present. In other words, in this embodiment, all end sounds, background sounds, and intermediate sounds are output from the main speakers 23ML and 23MR.

[0081] 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.

[0082] As shown in FIG12 , the output control unit 103 of this embodiment outputs the Lch end sound, Lch background sound, and Lch middle sound from the left main speaker 23ML, and outputs the Rch end sound, Rch background sound, and Rch middle sound from the right main speaker 23MR.

[0083] As shown in FIG13 , the sound image localization adjustment unit 102 of this embodiment adjusts the independent components so that the left sound image LL of the end sound is localized to the left of the left main speaker 23ML, and the right sound image RR of the end sound is localized to the right 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 sound is located to the left of the left main speaker 23ML, and the right end of the sound image UU is located to the right 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 of the sound image L2 of the center sound is localized to the left of the left main speaker 23ML, and the right end of the sound image R2 of the center sound is localized to the right of the right main speaker 23MR.

[0084] 14 is a diagram showing an example of sound image localization adjustment processing for independent components IL, IR and 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 uncorrelated components UL, UR using crosstalk cancellation.

[0085] In FIG14 , the components indicated by the dotted lines correspond to the correction components used to achieve crosstalk cancellation. That is, as components of Lch, a correction component -0.96*IR' with an opposite phase to the independent component 1.96*IR of Rch and a correction component -0.96*UR' with an opposite phase to the uncorrelated component 1.96*UR of Rch are added. In addition, as components of Rch, a correction component -0.96*IL' with an opposite phase to the independent component 1.96*IL of Lch and a correction component -0.96*UL' with an opposite phase to the uncorrelated component 1.96*UL of Lch are added. Such correction components can be generated, for example, using a well-known crosstalk cancellation circuit. By using such correction components, the sound image LL on the left side of the end sound can be shifted to the left side of the setting position of the left main speaker 23ML, and the sound image RR on the right side of the end sound can be shifted to the right side of the setting position of the right main speaker 23MR. Furthermore, the sound image UU of the background sound can be propagated so that its left end reaches the left side of the installation position of the left main speaker 23ML and its right end reaches the right side of the installation position of the right main speaker 23MR.

[0086] 15 is a flowchart showing an example of processing performed by the DSP 21 according to the second embodiment. In step S201, the separation unit 101 separates independent components IL, IR, uncorrelated components UL, UR, and correlated components CC, CL1, CL2, CR1, CR2 from input signals il, ir.

[0087] In step S202, the sound image localization adjustment unit 102 performs sound field localization adjustment processing to adjust the independent components so that the left sound image LL of the end sound is localized to the left of the left main speaker 23ML, and the right sound image RR of the end sound is localized to the right of the right main speaker 23MR. Furthermore, the sound image localization adjustment unit 102 performs sound field localization adjustment processing to adjust the uncorrelated components so that the left end of the sound image UU of the background sound is located to the left of the left main speaker 23ML, and the right end of the sound image UU is located to the right of the right main speaker 23MR. Furthermore, the sound image localization adjustment unit 102 performs sound field localization adjustment processing to adjust the correlated components so that the left end of the sound image L2 of the center sound is localized to the left of the left main speaker 23ML, and the right end of the sound image R2 of the center sound is localized to the right of the right main speaker 23MR.

[0088] In step S203, the output control unit 103 causes the main speakers 23ML and 23MR to output the end sound generated from the independent components, the background sound generated from the uncorrelated components, and the center sound generated from the correlated components. As a result, the left and right sound images LL and RR of the end sound are positioned outward of the left and right main speakers 23ML and 23MR, respectively, while the sound images C, L1, L2, R1, and R2 of the center sound are positioned between the left and right sound images LL and RR of the end sound. Furthermore, the sound image UU of the background sound is positioned so that its left end reaches to the left of the position of the left main speaker 23ML and its right end reaches to the right of the position of the right main speaker 23MR.

[0089] As described above, according to this embodiment, without using side speakers 23SL and 23SM, the sound images LL and RR of the end sounds generated based on the independent components can be localized near the left and right ends of the display 31, while ensuring a wide area for localizing the sound images C, L1, L2, R1, and R2 of the center sounds. Furthermore, 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 allows for the formation of a high-quality sound image using only two speakers, enabling the output of high-quality sound with a high sense of presence while suppressing any increase in cost.

[0090] Third embodiment

[0091] FIG16 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, three center speakers are added to the speakers of the first embodiment. The display device 1 according to 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 speaker 30SL (an example of a second left speaker), and a right 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.

[0092] The left main speaker 30ML is arranged near the left end of the lower part of the display 31. The right main speaker 30MR is arranged near the right end of the lower part of the display 31. The left speaker 30SL is arranged on the left side of the face of the display 31 and is located on the upper left side of the left main speaker 30ML. The right speaker 30SR is arranged on the right side of the face of the display 31 and is located on the upper right side of the right main speaker 30MR. Furthermore, the center speaker 30SC is arranged in the lower center of the display 31. The left center speaker 30SCL is arranged between the center speaker 30SC and the left main speaker 30ML. The right center speaker 30SCR is arranged between the center speaker 30SC and the right main speaker 30MR.

[0093] Sound images LL and RR are the end sounds output from the left and right speakers 30SL and 30SR and are localized at the positions of the left and right speakers 30SL and 30SR. Sound images L2 and R2 are the left and right main sounds output from the left main speaker 30ML and the right main speaker 30MR and are localized at the positions of the left and right main speakers 30ML and 30MR. Sound images L1 and R1 are the 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. Sound image C is the center sound output from the center speaker 30SC and is localized at the position of the center speaker 30SC.

[0094] Therefore, each speaker outputs a separate component of sound. It should be noted that the above speaker placement is an example and is not limited to this. That is, the placement could be at the top rather than the bottom. Furthermore, while the example of assigning the end sound, background sound, and center sound to each speaker is used separately, the number of speakers is not limited.

[0095] 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 to 303 , sound image localization adjustment units 311 to 312 , and output control units 321 to 327 .

[0096] 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 the sound signals input to the DSP 21, namely the Lch input signal and the Rch input signal, into independent components, uncorrelated components, and correlated components. The input signal is also called the input sound signal. The independent components and uncorrelated components are then sent to the output control unit 321 and the output control unit 322. Furthermore, the correlated components are sent to the first sound image localization adjustment unit 311. The Lch input signal is a signal corresponding to the left channel in a two-channel stereo playback of sound, and the Rch input signal is a signal corresponding to the right channel in the stereo playback. An uncorrelated component, for example, indicates that there is no correlation between the sound signal output in the left channel and the sound signal output in the right channel compared to a specified value. A correlated component, for example, indicates that there is a correlation between the left channel and the right channel that is greater than a specified value.

[0097] The second separation unit 302 separates the sound signals input from the first sound image localization adjustment unit 311, namely, the Lch input signal and the Rch input signal, into a second correlated component and a second independent component. The second independent component is then transmitted to the output control units 323 and 324. Furthermore, the second correlated component is transmitted to the second sound image localization adjustment unit 312. Similarly, the third separation unit 303 separates the sound signals input from the second sound image localization adjustment unit 312, namely, the Lch input signal and the Rch input signal, into a third correlated component and a third independent component. The third independent component is then transmitted to the output control units 325 and 326. Furthermore, the third correlated component is transmitted to the output control unit 327. It should be noted that while the description is based on the third separation unit 303 as an example, multiple separation units may be provided.

[0098] 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 that a second independent component is derived based on the correlated component input from the first separation unit 301. This allows the weights of the second independent component and the second correlated component to be adjusted based on the correlated component, thereby deriving the second independent component that localizes the sound image at the speaker positions. Specifically, the second independent component and the second correlated component are adjusted based on the correlated component so that the sound image is localized at the positions of the left main speaker 30ML and the right main speaker 30MR.

[0099] The second sound image localization adjustment unit 312 also performs the same processing as the first sound image localization adjustment unit 311. It adjusts the weights of the left and right channels so that a third independent component is derived based on the second correlated component from the second separation unit 302. This allows the weights of the third independent component and the third correlated component to be adjusted based on the second correlated component, thereby deriving the third independent component that localizes the sound image at the speaker positions. In other words, the third independent component and the third correlated component are adjusted based on the second correlated component so that the sound image is localized at the positions of the left center speaker 30SCL and the right center speaker 30SCR.

[0100] Output control units 321 to 327 are assigned to various speakers. For example, output control unit 321 is assigned to left speaker 30SL and is controlled to output Lch end sounds and Lch background sounds. Output control unit 322 is assigned to right speaker 30SR and is controlled to output Rch end sounds and Rch background sounds. Furthermore, output control units 321 and 322 receive inputs of uncorrelated components and independent components from first separation unit 301.

[0101] The output control unit 323 is assigned to the left main speaker 30ML and is controlled to output the Lch main sound. The output control unit 324 is assigned to the right main speaker 30MR and is controlled to output the Rch main sound. Furthermore, the output control units 323 and 324 receive the second independent component from the second separation unit 302.

[0102] The output control unit 325 is assigned to the left center speaker 30SCL and controls the output of the Lch center sound. The output control unit 326 is assigned to the left center speaker 30SCR and controls the output of the Rch center sound. Furthermore, the output control units 325 and 326 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 the output of the center sound. Furthermore, the third correlated component is input from the third separation unit 303. It should be noted that the remaining configurations may be the same as those of the first embodiment.

[0103] In the third embodiment, an example of an input signal to the first separation unit 301 is shown in FIG5 . Furthermore, an example of how the first separation unit 301 separates uncorrelated components from independent components is shown in FIG6 and FIG7 . Next, an example of the adjustment process performed by the first sound image localization adjustment unit 311 is shown in FIG9 . The adjusted signal shown in FIG9 is output to the second separation unit 302.

[0104] 18 is a diagram showing an example of input signals to the second separation unit 302 according to the third embodiment. In the third embodiment, the Lch input signal il includes the second independent component CL2 and the second correlated components CC, CL1, and CR1, and the Rch input signal ir includes the second independent component CR2 and the second correlated components CC, CL1, and CR1.

[0105] The second independent component CL2 included in the Lch input signal il is unrelated to the Rch input signal ir and corresponds to the Lch primary sound on the left. The second independent component CR2 included in the Rch input signal ir is unrelated to the Lch input signal il and corresponds to the Rch primary sound on the right.

[0106] The primary sound is, for example, a sound whose sound image is localized inward of an end sound localized at or near the left or right ends of the display 31. For example, the sound image of the left Lch primary sound is localized at the position of the left main speaker 30ML. The sound image of the right Rch primary sound is localized at the position of the right main speaker 30MR.

[0107] As shown in FIG18 , the weight 1.34, which is the value multiplied by the second independent components CL2 and CR2, represents the difference in sound output level (volume) between the left and right channels. Specifically, the left Lch primary sound corresponding to the second independent component CL2 is output entirely from the left channel, not from the right channel, while the right Rch primary sound corresponding to the second independent component CR2 is output entirely from the right channel, not from the left channel.

[0108] The second correlated components CC, CL1, and CR1 are components that correlate with the center sound, and are related to the Rch input signal ir and the Lch input signal il. The weights (0.99, 0.70, and 0.41 in this example) multiplied by the second correlated components CC, CL1, and CR1 respectively represent the difference in sound output level between the left and right channels.

[0109] That is, the output level of the Lch center sound corresponding to the second correlated component CL1 from the left channel is higher than the output level from the right channel. In addition, the output level of the Rch center sound corresponding to the second correlated component CR1 from the right channel is higher than the output level from the left channel.

[0110] Based on the differences between the input signals il, ir and the target signals tl, tr as described above, the second independent components CL2, CR2 can be separated.

[0111] FIG19 illustrates an example of a method for separating the second independent component CR2 based on the difference between the Lch input signal i1 and the Lch target signal t1 supplied to the second separation unit 302 according to the third embodiment. As described above, the Lch target signal t1 is the signal obtained by subtracting the Rch input signal ir from the Lch input signal i1. As shown in FIG19 , since both the Lch input signal i1 and the Lch target signal t1 contain the Lch second independent component CL2 and the second correlated component 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 then transmitted to the output control unit 324.

[0112] FIG20 illustrates an example of a method for separating the second independent component CL2 based on the difference between the Rch input signal ir and the Rch target signal tr supplied to the second separation unit 302 according to the third embodiment. As described above, the Rch target signal tr is the signal obtained by subtracting the Lch input signal il from the Rch input signal ir. As shown in FIG20 , since both the Rch input signal ir and the Rch target signal tr contain the Rch second independent component CR2 and the second correlated components CL1 and CR1, the Lch second independent component CL2 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. The Lch second independent component CL2 is then transmitted to the output control unit 323.

[0113] Then, as described above, the second separation unit 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. Furthermore, by taking the difference between the Rch second independent component CR2 separated as described above and the Rch input signal ir, the Rch second correlated components CC, CL1, and CR1 corresponding to the right channel can be separated.

[0114] 21 is a diagram showing an example of the sound image localization adjustment process performed by the second sound image localization adjustment unit 312 on the second correlation components CC, CL1, and CR1 according to the third embodiment.

[0115] The sound image L1 of the Lch center sound is adjusted so that it is localized at the installation position of the left center speaker 30SCL. In the state before adjustment in the upper portion of FIG21 , the weight of the right channel of the second correlation component CL1 on the left side is greater than 0 (0.41 in this example), so the sound image L1 of the Lch center sound is localized inward of the installation position of the left center speaker 30SCL.

[0116] Similarly, if the sound image R1 of the Rch center sound is to be localized at the installation position of the right center speaker 30SCR, in the state before adjustment in the upper part of FIG21 , the weight of the left channel of the second correlation component CR1 on the right side is greater than 0 (0.41 in this example), and therefore the sound image R1 of the Rch center sound is localized inward from the installation position of the right center speaker 30SCR.

[0117] Therefore, as shown in the adjusted state at the bottom of Figure 21, the weight of the right channel of the second correlated component CL1 on the left, that is, 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.

[0118] Similarly, the left channel weight of the right second correlated component CR1, that is, the output level of the left center speaker 30SCL, is set to 0, and the other weights are adjusted appropriately. This allows the sound image R1 of the Rch center sound to be localized at the installation position of the right center speaker 30SCR.

[0119] 22 is a diagram showing an example of input signals to the third separation unit 303 of the third embodiment. In the third embodiment, the Lch input signal il 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.

[0120] The third independent component CL1 included in the Lch input signal i1 is unrelated to the Rch input signal ir and corresponds to the Lch center sound on the left. The third independent component CR1 included in the Rch input signal ir is unrelated to the Lch input signal i1 and corresponds to the Rch center sound on the right.

[0121] The center sound is, for example, a sound whose sound image is localized inward of the main sound. The sound image of the main sound is localized inward of the left and right ends of the display 31. For example, the sound image of the left Lch center sound is localized at the position of the left center speaker 30SCL. The sound image of the right Rch center sound is localized at the position of the right center speaker 30SCR.

[0122] As shown in Figure 22, the weight 1.40, which is the value multiplied by the third independent components CL1 and CR1, represents the difference in sound output level (volume) between the left and right channels. Specifically, the left Lch center sound corresponding to the third independent component CL1 is entirely output from the left channel, not the right channel, while the right Rch center sound corresponding to the third independent component CR1 is entirely output from the right channel, not the left channel.

[0123] The third correlation component CC is a component corresponding to the center sound and correlated between the Rch input signal ir and the Lch input signal il. The value multiplied by the third correlation component CC, i.e., the weight (0.70 in this example), represents the difference in sound output level between the left and right channels.

[0124] Based on the differences between the input signals il, ir and the target signals tl, tr as described above, the third independent components CL1, CR1 can be separated.

[0125] FIG23 illustrates an example of a method for separating the third independent component CR1 based on the difference between the Lch input signal i1 and the Lch target signal t1 supplied to the third separation unit 303 according to the third embodiment. As described above, the Lch target signal t1 is the signal obtained by subtracting the Rch input signal ir from the Lch input signal i1. As shown in FIG23 , since both the Lch input signal i1 and the Lch target signal t1 contain the Lch third independent component CL1, 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 then transmitted to the output control unit 326.

[0126] FIG24 illustrates an example of a method for separating the third independent component CL1 based on the difference between the Rch input signal ir and the Rch target signal tr supplied to the third separation unit 303 according to the third embodiment. As described above, the Rch target signal tr is the signal obtained by subtracting the Lch input signal il from the Rch input signal ir. As shown in FIG24 , since both the Rch input signal ir and the Rch target signal tr contain the Rch third independent component CR1, the Lch third independent component CL1 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. The Lch third independent component CL1 is then transmitted to the output control unit 325.

[0127] Then, as described above, the third separation unit 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. Furthermore, the third correlated Rch component CC corresponding to the right channel can be separated by taking the difference between the Rch third independent component CR1 separated as described above and the Rch input signal ir.

[0128] 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 third correlated component CC, obtained by adding the left and right channel signals and multiplying them by 0.5, is sent to the output control unit 327. Thus, the center sound generated based on 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.

[0129] Next, FIG25 is a flowchart illustrating an example of processing performed by the DSP 21 according to the third embodiment. In step S301, the first separation unit 301 separates the independent components IL, IR, the uncorrelated components UL, UR, and the correlated components CC, CL1, CL2, CR1, and CR2 based on the input signals il and ir. Specifically, the first separation unit 301 separates the Lch independent component IL, the Lch uncorrelated component UL, and the Lch correlated components CC, CL1, CL2, CR1, and CR2 based on the Lch input signal il, and separates the Rch independent component IR, the Rch uncorrelated component UR, and the Rch correlated components CC, CL1, CL2, CR1, and CR2 based on the Rch input signal ir (step S301).

[0130] In step S302, the first sound image localization adjustment unit 311 performs sound field localization adjustment processing to further generate a second independent component based on the Lch and Rch related components CC, CL1, CL2, CR1, and CR2. Specifically, the Lch related component CL2 is adjusted so that the output level of the R channel is 0, thereby generating the Lch second independent component CL2. Similarly, the Rch related component CR2 is adjusted so that the output level of the L channel is 0, thereby generating the Rch second independent component CR2 (step S302).

[0131] In step S303, the second separation unit 302 separates the second independent components CL2 and CR2 and the second correlated components CC, CL1, and CR1 based on the Lch and Rch input signals i1 and ir from the first sound image localization adjustment unit. Specifically, the second independent Lch component CL2 and the second correlated Lch components CC, CL1, and CR1 are separated based on the Lch input signal i1, and the second independent Rch component CR2 and the second correlated Rch components CC, CL1, and CR1 are separated based on the Rch input signal ir (step S303).

[0132] In step S304, the second sound image localization adjustment unit 312 performs sound field localization adjustment processing to further generate a third independent component based on 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 is 0, thereby generating the Lch third independent component CL1. Similarly, the Rch second correlated component CR1 is adjusted so that the output level of the L channel is 0, thereby generating the Rch third independent component CR1 (step S304).

[0133] In step S305, the third separation unit 303 separates the third independent components CL1 and CR1 and the third correlated component CC based on the Lch and Rch input signals i1 and ir from the second sound image localization adjustment unit. Specifically, the third separation unit 303 separates the Lch third independent component CL1 and the Lch third correlated component CC based on the Lch input signal i1, and separates the Rch third independent component CR1 and the Rch third correlated component CC based on the Rch input signal ir (step S305).

[0134] In step S306, the first separation unit 301 distributes 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 distributed to the output control unit 322. The second separation unit 302 distributes the second independent component CL2 to the output control unit 323. The second independent component CR2 is distributed to the output control unit 324. The third separation unit 303 distributes the third independent component CL1 to the output control unit 325. The third independent component CR1 is distributed to the output control unit 326. Furthermore, the third correlated component CC is distributed to the output control unit 327 (step S306).

[0135] In step S307, the output control unit 321 controls the left speaker 30SL to output the Lch end sound generated based on the independent component IL and the Lch background sound generated based on the uncorrelated component UL. Similarly, the output control unit 322 controls the right speaker 30SR to output the Rch end sound generated based on the independent component IR and the Rch background sound generated based on the uncorrelated component UR.

[0136] The output control unit 323 also controls the left main speaker 30ML to output the Lch primary sound generated based on the second independent component CL2, and similarly, the output control unit 324 controls the right main speaker 30MR to output the Rch primary sound generated based on the second independent component CR2.

[0137] Furthermore, the output control unit 325 controls the left center speaker 30SCL to output the Lch center sound generated based on the third independent component CL1. Similarly, the output control unit 326 controls the right center speaker 30SCR to output the Rch center sound generated based on the third independent component CR1. The output control unit 327 controls the center speaker 30SC to output the center sound generated based on the third correlated component CC (step S307).

[0138] As a result, the sound image LL on the left side of the end sound is localized at the installation position of the left speaker 30SL, and the sound image RR on the right side of the end sound is localized at the installation position of the right speaker 30SR. In addition, the sound image UU of the background sound is localized so as to propagate in the space between the installation positions of the left speaker 30SL and the installation position of the right speaker 30SR.

[0139] In addition, 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.

[0140] 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.

[0141] As described above, according to this embodiment, the independent components, uncorrelated components, and correlated components assigned to each speaker are separated based on the left and right input signals, and further, the correlated components are separated into a second independent component and a second correlated component, thereby enabling the background sound generated based on the uncorrelated components and the end sound generated based on the independent components to be assigned to the left and right speakers and output. In addition, the sound composed of the correlated components can be assigned to the central speaker and output. In this way, a sound image localized to each speaker can be generated, and the sound images can be prevented from overlapping each other. As a result, the degradation of the sound and the reduction of the sense of presence can be suppressed. In addition, by generating independent components using the first separation unit and the second separation unit, a sound image independent of the independent components can be formed from each speaker.

[0142] Furthermore, by separating the sound into independent components and correlated components using the third separation unit, the sound composed of the independent components can be distributed to each speaker. Specifically, the sound composed of the independent components can be distributed to the left and right speakers, the left main speaker, the right main speaker, the left center speaker, and the right center speaker. This allows the formation of independent sound images from each speaker, enabling the output of high-quality sound with a high sense of presence.

[0143] Fourth embodiment

[0144] FIG26 is a diagram showing an example of the configuration of multiple speakers of a display device 1 according to a fourth embodiment. In this embodiment, a configuration is shown in which one center speaker is removed from the speakers of the third embodiment. The display device 1 according to 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 speaker 40SL (an example of a second left speaker), and a right 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).

[0145] FIG27 is a diagram showing an example of the functional configuration of the DSP 21 according to the fourth embodiment. The DSP 21 according to 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 removed.

[0146] 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 that of the third embodiment.

[0147] The sound signals output from the second sound image localization adjustment unit 412 , that is, the third correlated component of the Lch output signal and the Rch output signal and the third independent component are sent to the output control units 425 and 426 .

[0148] In the fourth embodiment, since there is no speaker assigned to the third correlated component, the left and right channel signals of the third correlated component are respectively assigned to the left center speaker 40SCL and the right center speaker 40SCR. Thus, the third correlated component can localize the sound image between the left center speaker 40SCL and the right center speaker 40SCR.

[0149] The audio device of the present embodiment is provided in a display device such as a television, for example. However, a speaker connected to a television and used may also have the functions of the audio device of the present application.

[0150] The program for realizing the functions of the display device 1 (DSP 21) described above may be provided as a file that can be installed on a computer or as an executable file recorded on a computer-readable storage medium such as a CD-ROM, floppy disk (FD), CD-R, or DVD (Digital Versatile Disk). Alternatively, the program may be stored on a computer connected to a network such as the Internet and downloaded via the network. Alternatively, the program may be provided or distributed via a network such as the Internet.

[0151] Several embodiments of the present invention have been described above. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms and can be omitted, replaced, or modified without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention and are included in the technical solutions described in the claims and their equivalents.

Claims

1. An audio device that performs processing for outputting sound from a plurality of speakers, wherein The audio device comprises: a separation unit for separating, based on a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component, an uncorrelated component, and a correlated component, the independent component having no correlation between the left channel and the right channel and corresponding to an edge sound whose sound image is localized at the left or right end of a predetermined area; the uncorrelated component having no correlation between the left channel and the right channel and corresponding to a background sound whose sound image is wider than that of the edge sound; and the correlated component having a correlation between the left channel and the right channel and corresponding to an intermediate sound whose sound image is localized inward of the localized positions of the left and right edge sounds; 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 end sound generated based on the independent component are localized at the left and right ends of the predetermined area, and the sound image of the middle sound generated based on the correlated component is localized between the localized positions of the left and right sound images of the end sound; and An output control unit causes the end sound, the background sound, and the intermediate sound to be output from the plurality of speakers.

2. The audio device according to claim 1, wherein The plurality of speakers include a first left speaker, a first right speaker disposed to the right of the first left 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 causes the middle sound to be output from the first left speaker and the first right speaker, and causes the end sound and the background sound to be output from the second left speaker and the second right speaker. The sound image localization adjustment unit adjusts the independent component so that the sound image on the left side of the end sound is localized at the setting position of the second left speaker, and the sound image on the right side of the end sound is localized at the setting position of the second right speaker, and the sound image localization adjustment unit adjusts the associated component so that the sound image on the left end of the middle sound is localized at the setting position of the first left speaker, and the sound image on the right end of the middle sound is localized at the setting position of the first right speaker.

3. The audio device according to claim 1, wherein 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 causes the end sound, the background sound, and the middle sound to be output from the first left speaker and the first right speaker. The sound image localization adjustment unit adjusts the independent components so that the sound image on the left side of the end sound is localized to the left of the setting position of the first left speaker, and the sound image on the right side of the end sound is localized to the right of the setting position of the first right speaker, and the sound image localization adjustment unit adjusts the associated components so that the sound image on the left end of the middle sound is localized at the setting position of the first left speaker, and the sound image on the right end of the middle sound is localized at the setting position of the first right speaker.

4. The audio device according to claim 3, wherein The sound image localization adjustment unit adjusts the uncorrelated component so that the left end of the sound image of the background sound reaches to the left of the installation position of the first left speaker and the right end of the sound image reaches to the right of the installation position of the first right speaker.

5. The audio device according to any one of claims 1 to 4, wherein The separation unit includes a filtering unit and a coefficient updating unit, The filter unit applies a finite impulse response based on predetermined coefficients to the left input signal and the right input signal, thereby outputting an output signal corresponding to a component correlated with a target signal, wherein the target signal is a signal based on a difference between the left input signal and the right input signal. The coefficient updating unit updates the coefficient so that a value of an error signal based on a difference between the target signal and the output signal is minimized.

6. An audio control method for outputting sound from a plurality of speakers, wherein: The audio control method comprises the following steps: Separating, based on a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component, an uncorrelated component, and a correlated component, the independent component having no correlation between the left channel and the right channel and corresponding to an end sound whose sound image is localized at the left or right end of a predetermined area; the uncorrelated component having no correlation between the left channel and the right channel and corresponding to a background sound whose sound image is wider than that of the end sound; and the correlated component having a correlation between the left channel and the right channel and corresponding to an intermediate sound whose sound image is localized inward of the localized position of the left and right end sounds; adjusting at least one of the correlated component and the independent component so that the left and right sound images of the end sound generated based on the independent component are localized at the left and right ends of the predetermined area, and the sound image of the middle sound generated based on the correlated component is localized between the localized positions of the left and right sound images of the end sound; and The end sound, the background sound, and the intermediate sound are output from the plurality of speakers.

7. A nonvolatile storage medium storing a program for causing an information processing device that performs processing for outputting sound from a plurality of speakers to execute the following processing: Separating, based on a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component, an uncorrelated component, and a correlated component, the independent component having no correlation between the left channel and the right channel and corresponding to an end sound whose sound image is localized at the left or right end of a predetermined area; the uncorrelated component having no correlation between the left channel and the right channel and corresponding to a background sound whose sound image is wider than that of the end sound; and the correlated component having a correlation between the left channel and the right channel and corresponding to an intermediate sound whose sound image is localized inward of the localized position of the left and right end sounds; adjusting at least one of the correlated component and the independent component so that the left and right sound images of the end sound generated based on the independent component are localized at the left and right ends of the predetermined area, and the sound image of the middle sound generated based on the correlated component is localized between the localized positions of the left and right sound images of the end sound; and The end sound, the background sound, and the intermediate sound are output from the plurality of speakers.

8. An audio device comprising at least: a first separation unit for separating, based on a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component, an uncorrelated component, and a correlated component, wherein the independent component has no correlation between the left channel and the right channel and localizes a sound image through a single channel; the uncorrelated component has no correlation between the left channel and the right channel and corresponds to background sound in a wider range than the sound image of the independent component; and the correlated component has a correlation between the left channel and the right channel and localizes a sound image through the left channel and the right channel inward of the sound image of the independent component; a first sound image localization adjustment unit configured to adjust the associated component into a second independent component and a second associated component, wherein the second independent component is generated on the left side by the left channel and on the right side by the right channel, and the sound image of the second associated component is localized inwardly of the sound image of the second independent component; a second separation unit, which separates the adjusted second independent component and second correlated component into the second independent component and the second correlated component; and An output control section performs control so that the components output from the first separation section and the second separation section are output from a plurality of speakers.

9. The audio device according to claim 8, wherein The audio device further comprises at least: a second sound image localization adjustment unit that adjusts the second correlated component into a third independent component and a third correlated component, wherein the third independent component is generated on the left side by the left channel and on the right side by the right channel, and the sound image of the third correlated component is localized inwardly of the sound image of the third independent component; and a third separation unit, which separates the adjusted third independent component and the third correlated component into the third independent component and the third correlated component; The output control unit performs control so that the components output from the first separation unit, the second separation unit, and the third separation unit are output from the plurality of speakers.

10. An audio control method for outputting sound from a plurality of speakers, wherein: The audio control method comprises at least the following steps: A first separation step comprises separating, based on a left input signal corresponding to a left channel and a right input signal corresponding to a right channel, an independent component, an uncorrelated component, and a correlated component, wherein the independent component has no correlation between the left channel and the right channel and localizes a sound image through a single channel; the uncorrelated component has no correlation between the left channel and the right channel and corresponds to background sound in a wider range than the sound image of the independent component; and the correlated component has a correlation between the left channel and the right channel and localizes a sound image through the left channel and the right channel inward of the sound image of the independent component; adjusting the associated component into a second independent component and a second associated component, wherein the second independent component is generated on the left side by the left channel and on the right side by the right channel, and a sound image of the second associated component is positioned inside the sound image of the second independent component; a second separation step of separating the adjusted second independent component and the second correlated component into the second independent component and the second correlated component; as well as The output control step performs control so that the components output from the first separation step and the second separation step are output from the plurality of speakers.

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