Audio device and audio control method

Abstract

The present application relates to an audio device and an audio control method, which are capable of forming high-quality sound images based on sound signals with in-phase and equal-amplitude components. The audio device is configured to process sound output from a plurality of loudspeakers, and comprises: a first separation unit configured to respectively separate, from a left input sound signal corresponding to a left channel and a right input sound signal corresponding to a right channel, associated components used for forming sound image localization; a second separation unit configured to separate, from sound signals separated by the first separation unit, sound signal components that become in-phase and equal-amplitude components; and an output control unit configured to control so that the sound signals separated by the second separation unit are output from the plurality of loudspeakers.

Description

Audio device and audio control method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Japanese patent application No. 2024-055249, filed with the Japan Patent Office on March 29, 2024, and entitled “Audio Device, Audio Control Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to an audio device and an audio control method. Background Art

[0004] In devices that output sound, methods are known for extracting components that are in phase between two channels from a two-channel stereo signal. For example, the following method is disclosed: separating highly correlated components from less correlated components between the two channels and then adding the highly correlated components to extract the in-phase components.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 5065784. Summary of the Invention

[0008] However, the highly correlated components in conventional techniques include various weighted components, resulting in incorrectly correlated components being added to the uncorrelated signal output. Consequently, when attempting to localize sound using the sound output from a speaker, conventional sound localization techniques fail to accurately reproduce the sound, resulting in perceived 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 and an audio control method that can form a high-quality sound image based on a sound signal with in-phase and in-amplitude components.

[0010] One embodiment of the present application is an audio device that performs processing for outputting sound from multiple speakers, comprising: a first separation unit that separates associated components for forming sound image localization from a left input sound signal corresponding to a left channel and a right input sound signal corresponding to a right channel; a second separation unit that separates sound signal components that have an amplitude deviation below a prescribed value and a phase deviation within a prescribed range from the sound signal separated by the first separation unit, thereby becoming components of the same phase and amplitude; and an output control unit that controls so that the sound signal separated by the second separation unit is 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 components included in an input signal to a second separation unit according to the first embodiment;

[0019] 9 is a diagram showing an example of a method of separating the same-phase and same-amplitude components by the second separation unit according to the first embodiment;

[0020] 10 is a diagram showing an example of components included in the output signal of the first embodiment;

[0021] 11 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the first embodiment;

[0022] FIG12 is a diagram showing an example of the structure of a plurality of speakers according to the second embodiment;

[0023] 13 is a diagram showing an example of the structure of a separation unit according to a second embodiment;

[0024] FIG. 14 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the second embodiment.

[0025] Explanation of the reference numerals 1…display device, 21…DSP (audio device), 23L…left speaker, 23R…right speaker, 23C…center speaker, 101…first separation unit, 102…second separation unit, 103…output control unit, 201L, 201R…adaptive filter (filtering unit), 211L, 211R…adaptive algorithm (coefficient updating unit), 301…adaptive filter, 311…adaptive algorithm, 302…filter circuit, C, L1, L2, LL, R1, R2, RR, UU…sound and image. DETAILED DESCRIPTION

[0026] Hereinafter, exemplary embodiments of the present application will be disclosed.

[0027] First embodiment

[0028] FIG1 is a diagram showing an example of the hardware structure of a display device 1 equipped with a first embodiment of an audio device, i.e., a DSP, to which an example of the present application is applied. The display device 1 is a device capable of displaying images and outputting sounds, such as a television set. 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, a sound decoder 16, a sound input ADC (Analog Digital Converter) 17, a DSP (Digital Signal Processor) 21 (an example of an audio device), an amplifier 22, a speaker 23, and a display 31. It should be noted that the function of the audio device of the present application can also be provided in a speaker connected to a television set.

[0029] 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.

[0030] 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.

[0031] The DSP 21 is an audio 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 sound output from each of the multiple speakers 23 built into the display device 1 to achieve predetermined sound image localization. The audio signals processed by the DSP 21 are output to each speaker 23 via the amplifier 22.

[0032] FIG2 is a diagram illustrating an example of the configuration of multiple speakers 23 according to the first embodiment. FIG2 illustrates the display device 1 as viewed from the front side of the display 31. FIG2 illustrates the case where there are three speakers 23 as shown in FIG1.

[0033] As shown in FIG2 , the display device 1 of this embodiment includes a left speaker 23L, a right speaker 23R, and a center speaker 23C. The left speaker 23L is located near the left end of the lower portion of the display 31. The right speaker 23R is located near the right end of the lower portion of the display 31. The center speaker 23C is located in the center of the lower portion of the display 31. In other words, it is located between the left speaker 23L and the right speaker 23R. Alternatively, for example, the plurality of speakers may be composed of a left speaker 23L located to the left of the listener, a right speaker 23R located to the right of the listener, and a center speaker 23C located between the left speaker 23L and the right speaker 23R when viewed by the listener.

[0034] It should be noted that the arrangement of the left speaker 23L, the right speaker 23R, and the center speaker 23C is an example and is not limited to the above.

[0035] FIG3 is a diagram showing an example of the functional configuration of the DSP 21 according to the first embodiment. The DSP 21 according to this embodiment includes a first separation unit 101, a second separation unit 102, and an output control unit 103. These functional units are implemented by the collaboration of the DSP 21 (illustrated in FIG1 ) as hardware and software. Alternatively, at least one of these functional units may be implemented as dedicated hardware (e.g., circuitry).

[0036] The first separation unit 101 separates correlated components from the Lch input signal and the Rch input signal, the audio signals input to the DSP 21. Specifically, it separates independent components and uncorrelated components, and then separates the correlated components. The correlated components are then output to the second separation unit 102. The Lch input signal corresponds to the left channel in a two-channel stereo broadcast, while the Rch input signal corresponds to the right channel in this stereo broadcast. The input signals are also referred to as input audio signals.

[0037] Independent components refer to sound signals output from either the left or right channel, with no correlation between the left and right channels. Furthermore, independent components correspond to edge sounds, the sound images of which are localized at the left or right edge of display 31 (an example of a predetermined area).

[0038] The so-called uncorrelated component is a component of the sound signal corresponding to background sound with a wider sound image range than the edge sound, and has no correlation between the sound signal output from the left channel and the sound signal output from the right channel compared to a predetermined value.

[0039] The so-called correlated component refers to a signal that has a correlation degree of more than a specified value between the left channel and the right channel and is output by the left channel and the right channel. In addition, the correlated component is a component corresponding to the middle sound, the sound image of which is positioned inward compared to the localization position of the sound image of the end sound. Furthermore, the correlated component includes a sound signal component that is an in-phase and in-amplitude component corresponding to the central sound whose sound image is positioned in the center of the display 31 (an example of a specified area). The in-phase and in-amplitude component is, for example, a signal whose amplitude deviation is less than a specified value and whose phase deviation converges within a certain range. The specified value of the amplitude deviation is, for example, less than 1dB.

[0040] The signals of the correlated components separated by the first separator 101 are input to the second separator 102. The second separator 102 separates the in-phase and in-amplitude components CC from the Lch input signal and the Rch input signal, which are the correlated components. The first separator 101 separates the correlated components, and the second separator 102 separates the in-phase and in-amplitude components from the correlated components. This allows the in-phase and in-amplitude components to be separated.

[0041] The output control unit 103 controls the signal generated from the in-phase and in-amplitude components to be distributed as a Cch output signal to the center speaker 23C and output from the center speaker 23C. Furthermore, the output control unit 103 controls the signal generated from the in-phase and in-amplitude components to be subtracted from the Lch input signal and the Rch input signal, which are the audio signals input to the DSP 21, respectively, as the Lch output signal and the Rch output signal. These signals are distributed as Lch output signals and Rch output signals to the left speaker 23L and the right speaker 23R, respectively, and output from the left speaker 23L and the right speaker 23R.

[0042] FIG4 is a diagram illustrating an example of the configuration of the first separation unit 101 and the second separation unit 102 of the first embodiment. First, the first separation unit 101 will be described. The first separation unit 101 illustrated here includes adaptive filters 201L and 201R (an example of a filtering unit) and adaptive algorithms 211L and 211R (an example of a coefficient updating unit).

[0043] Adaptive filters 201L and 201R apply finite impulse responses based on predetermined coefficients to the left Lch input signal xl(n) and the right Rch input signal xr(n), respectively, to output output signals ol(n) and or(n). Specifically, the Lch adaptive filter 201L corresponding to the left channel applies a finite impulse response based on the coefficients to the Lch input signal xl(n) to output the output signal ol(n) included in the Lch input signal. The Rch adaptive filter 201R corresponding to the right channel applies a finite impulse response based on the coefficients to the Rch input signal xr(n) to output the output signal or included in the Rch input signal.

[0044] Adaptive algorithms 211L and 211R are used to optimize the coefficients of adaptive filters 201L and 201R. Adaptive algorithms 211L and 211R update the coefficients of the adaptive filters 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 the target signal xl(n)-xr(n) and the target signal xr(n)-xl(n), which are based on the difference between the Lch input signal xl(n) and the Rch input signal xr(n), and the output signals ol(n) and or(n) output from adaptive filters 201L and 201R. In this example, n corresponds to time.

[0045] Specifically, the Lch adaptive algorithm 211L corresponding to the left channel updates the coefficients of the adaptive filter so that the value el(n) of the error signal is minimized. The value el(n) of the error signal is the difference between the Lch input signal xl(n) and the Rch input signal xr(n), that is, the target signal xl(n)-xr(n) multiplied by the specified weight gl, and the output signal ol(n) output from the Lch adaptive filter 201L.

[0046] In addition, the Rch adaptive algorithm 211R corresponding to the right channel updates the coefficients of the adaptive filter so that the value of the error signal er(n) is minimized. The value of the error signal er(n) is the difference between the Rch input signal xr(n) and the Lch input signal xl(n), that is, the target signal xr(n)-xl(n) multiplied by the specified weight gr, and the output signal or(n) output from the Rch adaptive filter 201R.

[0047] Adaptive filters 201L and 201R, whose coefficients are optimized by the adaptive algorithms 211L and 211R described above, separate the independent components and uncorrelated components corresponding to the error signals el(n) and er(n) from the input signals xl(n) and xr(n). The independent and uncorrelated components er(n) are then subtracted from the input signal xl(n) to separate the correlated component cl(n). Similarly, the correlated component cr(n) is separated by subtracting the independent and uncorrelated components el(n) from the input signal xr(n). The correlated components cl(n) and cr(n) are output to the second separation unit 102.

[0048] Furthermore, by adopting the above-described configuration, filtering (elimination) of irrelevant components by the adaptive filters 201L and 201R becomes unnecessary, and abrupt changes in the frequency characteristics of the filters are reduced, thereby suppressing the generation of components that cause abnormal sounds.

[0049] Next, a description will be given of the second separation unit 102. The second separation unit 102 illustrated here includes an adaptive filter 301 (an example of a filter unit) and an adaptive algorithm 311 (an example of a coefficient update unit).

[0050] Adaptive filter 301 applies a finite impulse response based on predetermined coefficients to cl(n)-cr(n), which is obtained by subtracting the Rch input signal from the Lch input signal, as input signals, and outputs an output signal oc(n). In other words, adaptive filter 301 applies a finite impulse response based on the coefficients to the input signals cl(n)-cr(n), and outputs the output signal oc(n) included in the input signals.

[0051] Adaptive algorithm 311 is an algorithm for optimizing the coefficients of adaptive filter 301. Adaptive algorithm 311 updates the coefficients of the adaptive filter so that the value of the error signal ec(n) is minimized. The error signal value ec(n) is based on the difference between the target signal cl(n)+cr(n) based on the addition of the Lch input signal cl(n) and the Rch input signal cr(n) and the output signal oc(n) output from the adaptive filter 301.

[0052] Specifically, the adaptive algorithm 311 of the second separation unit 102 updates the coefficients of the adaptive filter so that the value ec(n) of the error signal is minimized. The value ec(n) of the error signal is the difference between the value obtained by multiplying the target signal cl(n)+cr(n) obtained by adding the Lch input signal cl(n) and the Rch input signal cr(n) by the prescribed weight gc and the output signal oc(n) output from the adaptive filter 301.

[0053] Adaptive filter 301, whose coefficients have been optimized using adaptive algorithm 311 as described above, outputs the CC of the independent components corresponding to error signal ec(n) based on input signals cl(n)-cr(n), and separates the in-phase and in-amplitude components. Then, to align the in-phase and in-amplitude components corresponding to error signal ec(n) with the center component of Lch input signal xl(n) and Rch input signal xr(n), multiplier gcc is set to 0.5 and multiplied by error signal ec(n), thereby generating cc(n).

[0054] In addition, by subtracting the in-phase and in-amplitude component cc(n) from the Lch input signal xl(n) and subtracting the in-phase and in-amplitude component cc(n) from the Rch input signal xr(n), an Lch signal xl′(n) and an Rch signal xr′(n) that do not contain the in-phase and in-amplitude component cc(n) are generated.

[0055] The signal of the in-phase and in-amplitude component cc(n) is distributed as the Cch output signal to the center speaker. The Lch signal xl′(n) is distributed as the Lch output signal to the left speaker. Then, the Rch component xr′(n) is distributed as the Rch output signal to the right speaker.

[0056] 5 is a diagram showing an example of components included in the input signals xl(n) and xr(n) input to the first separation unit 101 according to the first embodiment. In this example, the Lch input signal xl(n) includes an uncorrelated component UL, an independent component IL, and correlated components CC, CL1, CL2, CR1, and CR2, and the Rch input signal xr(n) includes an uncorrelated component UR, an independent component IR, and correlated components CC, CL1, CL2, CR1, and CR2.

[0057] The signal level differences between the left and right input signals xl(n) and xr(n) input to DSP 21 are as follows: the correlated component CC is 0 dB, the correlated components CL1 and CR1 are 3 dB, the correlated components CL2 and CR2 are 6 dB, the uncorrelated components UL and UR are ∞, and the independent components IL and IR are ∞. In this embodiment, a method is described in which the signal level difference between the left and right output signals xl′(n) and xr′(n) output from DSP 21 is set to the same signal level difference as the signal level difference between the input signals xl(n) and xr(n), while making the correlated component CC independent.

[0058] The uncorrelated component UL included in the Lch input signal xl(n) is uncorrelated with the Rch input signal xr(n) and corresponds to background sound. The uncorrelated component UR included in the Rch input signal xr(n) is uncorrelated with the Lch input signal xl(n) and corresponds to background sound. Background sound, for example, is localized sound whose sound image is propagated to the entire left and right areas of the display 31.

[0059] The independent component IL included in the Lch input signal xl(n) is a component that is not associated with the Rch input signal xr(n) and corresponds to the left end sound. The independent component IR included in the Rch input signal xr(n) is a component that is not associated with the Lch input signal xl(n) and corresponds to the right end sound. 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 left end sound is localized at the left end of the display 31, and the sound image of the right end sound is localized at the right end of the display 31.

[0060] In Figure 5 , the weight of 1.0, which is the value multiplied by the independent components IL and IR, represents the difference in sound output level (volume) between the left and right channels. Specifically, the left-side edge sound corresponding to the independent component IL is output entirely from the left channel and not from the right channel, while the right-side edge sound corresponding to the independent component IR is output entirely from the right channel and not from the left channel.

[0061] Correlated components CC, CL1, CL2, CR1, and CR2 are components that correlate between the Rch input signal xr(n) and the Lch input signal xl(n) 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 left and right sound images of the center sound. Correlated component CL1 corresponds to a sound whose sound image is localized to the left of the center position 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 left end sound within the sound image range. Correlated component CR1 corresponds to a sound whose sound image is localized to the right of the center position 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 right end sound within the sound image range.

[0062] In Figure 5, the values ​​multiplied by 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), represent the output level difference of the sound between the left and right channels. That is, the output level of the middle 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 is shown 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 exemplified here are set so that when the weight in the left channel is set to Wl and the weight in the right channel is set to Wr, Wl 2 +Wr 2 becomes 1 or approximately 1. For example, the weight of the correlation component CL1 is 0.90. 2 +0.44 2 is approximately equal to 1.0, and 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.

[0063] Based on the differences between the input signals xl(n), xr(n) and the target signals xl(n)-xr(n), xr(n)-xl(n), the independent components IL, IR and the uncorrelated components UL, UR are separated.

[0064] FIG6 is a diagram illustrating an example of a method for separating independent components IR and uncorrelated components UR based on the difference between the Lch input signal xl(n) and the Lch target signal xl(n)-xr(n) according to the first embodiment. As described above, the Lch target signal xl(n)-xr(n) is a signal obtained by subtracting the Rch input signal xr(n) from the Lch input signal xl(n). As shown in FIG6 , since both the Lch input signal xl(n) and the Lch target signal xl(n)-xr(n) 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 xr(n) can be separated by taking the difference between the Lch input signal xl(n) and the Lch target signal xl(n)-xr(n).

[0065] FIG7 is a diagram illustrating an example of a method for separating independent components IL and uncorrelated components UL based on the difference between the Rch input signal xr(n) and the Rch target signal xr(n)-xl(n) according to the first embodiment. As described above, the Rch target signal xr(n)-xl(n) is a signal obtained by subtracting the Lch input signal xl(n) from the Rch input signal xr(n). As shown in FIG7 , since both the Rch input signal xr(n) and the Rch target signal xr(n)-xl(n) 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 xl(n) can be separated by taking the difference between the Rch input signal xr(n) and the Rch target signal xr(n)-xl(n).

[0066] Then, by taking the difference between the Lch independent component IL and the Lch uncorrelated component UL separated as described above and the Lch input signal xl(n), the Lch-correlated components CC, CL1, CL2, CR1, and CR2 corresponding to the left channel can be separated. Furthermore, by taking the difference between the Rch independent component IR and the Rch uncorrelated component UR separated as described above and the Rch input signal xr(n), the Rch-correlated components CC, CL1, CL2, CR1, and CR2 corresponding to the right channel can be separated.

[0067] Next, FIG8 is a diagram showing an example of components included in the input signal to the second separation unit 102 according to the first embodiment. Correlated components CC, CL1, CL2, CR1, and CR2 are output from the first separation unit 101 to the second separation unit 102. Specifically, components included in the Lch input signal cl(n) and components included in the Rch input signal cr(n) output from the first separation unit 101 are shown.

[0068] Figure 9 illustrates an example of a method for separating in-phase and in-amplitude components by the second separation unit in the first embodiment. As shown in Figure 9 , the input signal is obtained by subtracting the Rch input signal cr(n) from the Lch input signal cl(n). The input signal cl(n)-cr(n) represents the input signal to the adaptive filter. Furthermore, the input signal cl(n)-cr(n) represents the input signal to the adaptive algorithm. The target signal is obtained by adding the Lch input signal cl(n) and the Rch input signal cr(n).

[0069] The in-phase and in-amplitude components CC are separated as independent components based on the difference between the input signal cl(n)-cr(n) and the target signal cl(n)+cr(n) to the adaptive filter of the second separation unit 102. Because both the input signal cl(n)-cr(n) and the target signal cl(n)+cr(n) contain correlated components CL1, CL2, CR1, and CR2, the in-phase and in-amplitude components CC can be separated as independent components by taking the difference between the input signal cl(n)-cr(n) and the target signal cl(n)+cr(n).

[0070] Figure 10 illustrates an example of components included in the output signal of the first embodiment. As shown in Figure 10(a), the Cch output signal outputs an in-phase and in-amplitude component CC. For example, when the coefficient of multiplier gcc is set to 0.5, the weight of the in-phase and in-amplitude component CC is 0.7. Figure 10(b) illustrates the components included in the Lch output signal, the components included in the Rch output signal, and the signal level difference between the Lch and Rch output signals.

[0071] The components included in the Lch output signal are the result of subtracting the Cch output signal from the Lch input signal. Similarly, the components included in the Rch output signal are the result of subtracting the Cch output signal from the Rch input signal. Therefore, it is possible to output components that do not include the in-phase and in-amplitude component CC. Therefore, the Lch output signal can be output from the left speaker 23L, while the Rch output signal can be output from the right speaker 23R. Furthermore, the Cch output signal, after separating only the in-phase and in-amplitude component CC, can be output from the center speaker 23C.

[0072] Therefore, as shown by the signal level difference between the Lch output signal and the Rch output signal, the signal level difference of the output signal after removing the CC component is the same as the signal level difference of the input signal. Therefore, the components after removing the in-phase and in-amplitude components can produce the same sound image as the input signal.

[0073] FIG11 is a diagram illustrating an example of the relationship between the output locations of various sounds and the sound image in the first embodiment. As shown in FIG11 , the display device 1 includes a display 31, a left speaker 23L, a right speaker 23R, and a center speaker 23C. In this embodiment, the three speakers can be used to localize the sound image at multiple locations.

[0074] The output control unit 103 distributes the Cch output signal to the center speaker 23C, thereby localizing the sound image C of the in-phase and in-amplitude component CC at the installation position of the center speaker 23C. The output control unit 103 distributes the Lch output signal to the left speaker 23L and the Rch output signal to the right speaker 23R, thereby localizing the sound image UU of the uncorrelated components UL and UR so that they propagate in the space between the left speaker 23L and the right speaker 23R.

[0075] Furthermore, the output control unit 103 can distribute the Lch output signal to the left speaker 23L, thereby localizing the sound image LL of the independent component IL at the installation position of the left speaker 23L. Similarly, by distributing the Rch output signal to the right speaker 23R, the output control unit 103 can localize the sound image RR of the independent component IR at the installation position of the right speaker 23R.

[0076] Furthermore, the output control unit 103 can localize the sound images L2 , L1 , R1 , and R2 composed of the correlation components CL1 , CL2 , CR1 , and CR2 by using the left speaker 23L and the right speaker 23R.

[0077] Specifically, sound image LL shows the sound image on the left side of the Lch sound, and sound image RR shows the sound image on the right side of the Rch sound. Sound image UU shows the sound image of the background sound. Sound image C shows the sound image of the Cch sound. Sound images L1 and L2 show the sound image between the Lch and Cch sounds. Furthermore, sound images R1 and R2 show the sound image between the Rch and Cch sounds.

[0078] The output control unit 103 of this embodiment controls the left speaker 23L to output the Lch end sound generated based on the Lch independent component IL, and the right speaker 23R to output the Rch end sound generated based on the Rch independent component IR. This allows the sound image LL on the left side of the end sound to be localized at the installation position of the left speaker 23L, and the sound image RR on the right side of the end sound to be localized at the installation position of the right speaker 23R.

[0079] Furthermore, the output control unit 103 controls the left speaker 23L to output the Lch background sound generated based on the Lch uncorrelated component UL, and the right speaker 23R 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 23L and the installation position of the right speaker 23R.

[0080] Furthermore, the output control unit 103 controls the left speaker 23L to output the Lch intermediate sound generated based on the Lch-related components CL1, CL2, CR1, and CR2, and the right speaker 23R to output the Rch intermediate sound generated based on the Rch-related components CL1, CL2, CR1, and CR2. This allows the sound images L1, L2, R1, and R2 of the intermediate sound to be localized between the localized positions of the sound images LL and RR of the left and right end sounds.

[0081] The output control unit 103 also controls the center speaker 23C to output the Cch sound generated from the in-phase and in-amplitude component CC, thereby localizing the sound image C of the center sound at the position of the center speaker 23C.

[0082] This allows for a high-quality sound image localized at the center speaker without changing the sound image localization after removing the in-phase and in-amplitude components CC by extracting the in-phase and in-amplitude components from the stereo signal. Furthermore, by distributing the signals to the center speaker 23C using the first and second separation sections 101 and 102, a Cch output signal with clear localization of the sound image C can be generated.

[0083] Fig. 12 is a diagram showing an example of the configuration of a plurality of speakers according to Embodiment 2. Fig. 2 illustrates a state where the display device 1 is viewed from the front side of the display 31.

[0084] As shown in FIG12 , the display device 1 of this embodiment includes a left speaker 23L and a right speaker 23R. The left speaker 23L is located near the left end of the lower portion of the display 31. The right speaker 23R is located near the right end of the lower portion of the display 31. Alternatively, for example, when viewed from the listener, the plurality of speakers may consist of the left speaker 23L located to the left of the listener and the right speaker 23R located to the right of the listener. Alternatively, for example, the left speaker 23L and the right speaker 23R may be located on either side of the audio device.

[0085] It should be noted that the arrangement of the left speaker 23L and the right speaker 23R is an example and is not limited to the above.

[0086] Fig. 13 is a diagram showing an example of the configuration of the first separation unit 101 and the second separation unit 102 according to the second embodiment. The first separation unit 101 is the same as that of the first embodiment.

[0087] The second separation unit 102 is similar up to separating the in-phase and in-amplitude components CC. The second embodiment takes as an example a case where the center speaker 23C is removed and the filter circuit 302 is provided in the output control unit 103.

[0088] The in-phase and in-amplitude components CC separated by the second separation unit 102 are processed by the filter circuit 302. Then, they are added to the Lch input signal and the Rch input signal to generate an output signal in which only the in-phase and in-amplitude components CC of the Lch output signal and the Rch output signal are emphasized.

[0089] For example, when the coefficient of multiplier gcc is 0, the components of the Lch input signal and the Rch input signal are output unchanged. On the other hand, when the coefficient of multiplier gcc is 1, the components of the Lch input signal and the Rch input signal with the same phase and amplitude CC are emphasized and output. Therefore, the level of emphasis can be adjusted using the coefficient of multiplier gcc.

[0090] FIG14 is a diagram showing an example of the relationship between the output location of each sound and the sound image in the second embodiment. As shown in FIG14 , the display device 1 includes a display 31, a left speaker 23L, and a right speaker 23R. In the second embodiment, the sound image can be localized in multiple locations using two speakers.

[0091] 13 , the processing of the filter circuit 302 can emphasize only the sound image C composed of the in-phase and in-amplitude components CC. This improves the sound quality and allows the in-phase and in-amplitude components CC to be reproduced more clearly.

[0092] As described above, according to this embodiment, an audio device that performs processing for outputting sound from multiple speakers improves the quality of the sound image C localized by the sound output from the center speaker. The first separation unit, which separates the correlated components used to form the sound image localization from the Lch input sound signal and the Rch input sound signal, separates the correlated components. The second separation unit, which separates the correlated components into sound signal components with the same phase and amplitude, separates the same phase and amplitude components. The sound generated based on the same phase and amplitude components is distributed to the center speaker 23C. This improves the quality of the sound image C localized by the sound output from the center speaker. Consequently, the same phase and amplitude components CC can be reproduced more clearly.

[0093] Furthermore, control is performed such that the sound generated based on the in-phase and in-amplitude component CC is distributed to the center speaker, which is located between the two speakers of the audio device, and the left and right speakers, which are located on either side of the audio device. Furthermore, control is performed such that the sound signals obtained by subtracting the in-phase and in-amplitude component CC from the Lch input signal and the Rch input signal are distributed to the left and right speakers for output. This allows for the generation of sound images localized to the respective speakers. Consequently, it is possible to suppress the degradation of sound and the reduction of the sense of presence caused by overlapping sound images.

[0094] Furthermore, in the case of an audio device with left and right speakers located on either side of the device, instead of a center speaker, the sound signal generated by adding the in-phase and in-amplitude component CC generated by the second separation unit to the Lch input signal and the Rch input signal is distributed to the left and right speakers. This improves the sound image quality of the in-phase and in-amplitude component located in the center between the left and right speakers. Furthermore, by using the second separation unit to generate the in-phase and in-amplitude component CC, it is possible to emphasize only the in-phase and in-amplitude components output from the left and right speakers. This, in turn, reduces the degradation of sound and the reduction in the sense of presence caused by overlapping sound images.

[0095] 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 and provided via the network. Alternatively, the program may be provided or distributed via a network such as the Internet.

[0096] While the embodiments of the present application have been described above, 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 various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are intended to be included within the scope and spirit of the invention, and are intended to be 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 first separation unit for separating associated components for forming sound image localization from a left input sound signal corresponding to a left channel and a right input sound signal corresponding to a right channel; a second separation unit for separating a sound signal component having the same phase and amplitude from the sound signal separated by the first separation unit; as well as An output control unit controls so that the sound signals separated by the second separation portion are output from the plurality of speakers.

2. The audio device according to claim 1, wherein The plurality of speakers include, when viewed from the listener: a left speaker provided on the left side of the listener; a right speaker provided on the right side of the listener; and a center speaker provided between the left speaker and the right speaker. The output control unit controls so that the sound signal separated by the second separation part is output from the center speaker. The output control unit controls so that a sound signal obtained by subtracting the sound signal separated by the second separation unit from the left input sound signal is output from the left speaker. The output control section controls so that a sound signal obtained by subtracting the sound signal separated by the second separation section from the right input sound signal is output from the right speaker.

3. The audio device according to claim 1, wherein The plurality of speakers include, when viewed from the listener: a left speaker provided on the left side of the listener; and a right speaker provided on the right side of the listener, The output control unit controls so that a sound signal obtained by adding the sound signal separated by the second separation unit to the left input sound signal is output from the left speaker. The output control unit controls the right speaker to output a sound signal obtained by adding the sound signal separated by the second separation unit to the right input sound signal.

4. An audio control method that performs processing for outputting sound from a plurality of speakers, wherein: The audio control method comprises the following steps: A first step of separating correlation components for forming sound image localization from a left input sound signal corresponding to a left channel and a right input sound signal corresponding to a right channel respectively; a second step of separating the sound signal components into components having the same phase and the same amplitude from the sound signal separated in the first step; as well as A step of performing control so that the sound signals separated in the second step are output from the plurality of speakers.

Images