JP2012049652A - Multichannel audio reproducer and multichannel audio reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multichannel audio reproducer capable of correctly recognizing a sound source position regardless of a distance between the sound source and a listener.SOLUTION: A multichannel audio reproducer comprises a localization sound source estimation part 1 estimating a localization sound source signal when a localization sound source exists in an input multichannel audio signal, a sound source signal separation part 2 separating the input multichannel audio signal into the localization sound source signal and a non-localization sound source signal, a sound source position parameter calculation part 3 calculating a sound source position parameter based on signal components composing the localization sound source, a sound source position determination part 101 determining whether a sound source position specified by the sound source position parameter is in an area close to a listener or in a distant area, a first reproduction signal generation part 102 generating a reproduction signal to control the sound source position when it is in the distant area, a second reproduction signal generation part 103 generating a reproduction signal to control the sound source position when it is in the close area, and a switch part 104 switching between the first reproduction signal generation part 102 and the second reproduction signal generation part 103.

Description

  The present invention relates to a multi-channel audio playback apparatus and a multi-channel audio playback method that achieve high realism in multi-channel audio playback.

  With the spread of recording media such as DVD (Digital Versatile Disc) and BD (Blu-ray Disc) and digital television broadcasting, demand for multi-channel audio reproduction is increasing. The format most often used as a multi-channel audio signal is called 5.1ch surround, and the left channel (L), center channel (C), right channel (R) in front of the listener, and the rear of the listener. A total of 5 channels of surround left (Ls) and surround right (Rs) are arranged in The 0.1ch portion is called an LFE (Low Frequency Effect) channel, which mainly records only a low frequency component of several hundred Hz or less and is connected to a dedicated speaker called a subwoofer (SW). By connecting individual speakers to each audio channel and arranging the speakers on the same circumference surrounding the listener, multi-channel audio reproduction is realized.

  However, in an audio reproduction system in which speakers with a general number of audio channels are arranged on the same circumference, there are significant restrictions on the optimum speaker arrangement and listening position, and inappropriate speaker arrangement or optimum viewing position ( If you watch at a position outside the sweet spot), you cannot get a high sense of realism. As an example of solving this problem, the inventors of the present application have disclosed a playback device using a combination of a first speaker group disposed far away and a second speaker group disposed near the ear or headphones (Japanese Patent Application No. 2009). -084551). According to the technology used in this reproducing apparatus, the sound image position to be generated can be determined by appropriately distributing signal components between the first speaker group and the second speaker group and controlling each signal energy. Multi-channel audio playback with high precision and high realism is possible. FIG. 6 is a diagram illustrating an example of a configuration of a conventional multi-channel audio reproducing apparatus using a first speaker group and a second speaker group. As the first speaker group, peripheral speakers arranged at positions away from the listener are used, and the left channel (L) 5, the center channel (C) 6, the right channel (R) 7 in front of the listener, A total of five channels, a surround left channel (Ls) 9 and a surround right channel (Rs) 8, are arranged behind the listener. The LFE channel is not shown because it is used to reinforce the low frequency reproduction capability of the reproduction system and does not relate to the control of the sound image position. Moreover, headphones are used as the second speaker group. The headphones consist of a left headphone channel (Lh) 10 for the left ear and a right headphone channel (Rh) 11 for the right ear. The input multi-channel audio signal is a general 5ch surround signal, and is composed of signals corresponding to the L, C, R, Ls, and Rs channels. The localization sound source estimation unit 1 analyzes the input multi-channel audio signal and determines whether there is a localization sound source whose sound image position to be reproduced exists. When a localization sound source exists, the signal source constituting the localization sound source and other signal components are separated in the sound source signal separation unit 2. The sound source position parameter calculation unit 3 obtains a position where the localization sound source is localized in the reproduction acoustic space from the signal components constituting the localization sound source, and calculates a sound source position parameter. Based on the calculated sound source position parameter, the reproduction signal generating unit 4 distributes the signal components of the localization sound source to the peripheral speakers and headphones, and combines the signal components other than the localization sound source separated earlier, thereby And an output signal for each of the headphones. Here, the sound source position parameter is a direction angle γ of the localization sound source viewed from the listener and a distance r from the listener to the localization sound source.

  FIG. 2 is a diagram for explaining the process of allocating the localization sound source signal to the peripheral speakers and headphones in the reproduction signal generation unit 4. In the figure, 201 is the listening point that is the center position of the listener, 202 is the position of the stereophonic sound source, 203 is the L channel speaker, 204 is the C channel speaker, 205 is the R channel speaker, 206 is the Rs channel speaker, and 207 is the Ls channel. A speaker, 208 is an L channel headphone, 209 is an R channel headphone, and 210 is a fan-shaped region surrounded by the listening point, the L channel speaker, and the R channel speaker. Also, each peripheral speaker is arranged on the circumference surrounding the listening point, the L channel speaker and the R channel speaker, and the Ls channel speaker and the Rs channel speaker are arranged symmetrically with respect to the front of the listener, and the circumferential radius thereof is r0. It is. In addition, the output level of each peripheral speaker and headphone is adjusted so that the listener feels that the same volume of sound is being reproduced from each speaker and headphone when given a predetermined level of signal. The In general, in a multi-channel audio signal, a C channel signal is composed of signal components centered on a dialog, and other sound sources such as sound effects arranged in an acoustic space surrounding the listener are L, It is composed of signal components of R, Ls, and Rs channels. Therefore, L, R, Ls, and Rs speakers other than the C channel are used as peripheral speakers for controlling the position of the localization sound source. If there is a stereophonic sound source inside the sector created by the listening point and two neighboring speakers, the playback signal output from the speakers (headphones near the listening point and two peripheral speakers) placed at each vertex The position of the localization sound source is reproduced. In FIG. 2, the localization sound source 202 is in a fan-shaped region 210 surrounded by the listening point 201, the L channel speaker 203 and the R channel speaker 205. Therefore, the speakers used to control the position of the localization sound source 202 are headphones, an L channel speaker, and an R channel speaker near the listening point. When the signal component of the localization sound source 202 is X, and the direction angle γ of the localization sound source viewed from the listener and the distance r from the listener to the localization sound source are given, the distribution of signals to each speaker is as follows.

  First, the localization signal component X is distributed to the left signal Xl shown in Equation 1 and the right signal Xr shown in Equation 2.

  Here, the direction angle A is an angle representing the direction of the L channel speaker with respect to the front of the listener.

  Subsequently, the left signal Xl is distributed to the L channel speaker signal Xl_L shown in Expression 3 and the Lh channel headphone signal Xl_Lh shown in Expression 4.

  Similarly, the right signal Xr is distributed to the R channel speaker signal Xr_R shown in Expression 5 and the Rh channel headphone signal Xr_Rh shown in Expression 6.

  As described above, when the localization sound source 202 is in the fan-shaped region 210 surrounded by the listening point 201 and the L-channel speaker 203 and the R-channel speaker 205, the signal distributed to the speakers and headphones of each channel forming the fan-shaped vertex. Was calculated. Even when the localization sound source 202 is in a fan-shaped area surrounded by two adjacent neighboring speakers and listening points, the signals distributed to the speakers and headphones of each channel forming the fan-shaped apex are the same as described above. It can be calculated.

  The localization sound source signal components allocated to the peripheral speakers and headphones are combined with the signal components of the non-localized sound sources previously separated and then output to the peripheral speakers and headphones.

  In a conventional multi-channel audio reproduction system using a first speaker group disposed far away and a second speaker group disposed in the vicinity of the ear, each of the first speaker group and the second speaker group is used. The position of the localization sound source is controlled by changing the ratio of the signal energy to be reproduced. The control based on the ratio of the signal energy to be reproduced is based on the signal reproduced from each speaker when the sound source position is relatively far from the listener (for example, the sound source position is outside a radius of several tens of centimeters from the listener). A virtual sound image is generated by combining the components, and the listener can correctly recognize the sound source position. However, when the sound source position is very close to the listener (for example, the sound source position is inside the radius of several tens of centimeters from the listener), the distribution of the signal energy to be reproduced is the second speaker arranged near the ear. The distribution to the group becomes very large. That is, in the generation of the virtual sound image, the signal component reproduced from the second speaker group becomes dominant, and the contribution degree of the signal component reproduced from the first speaker group becomes very small. In order to control the sound source position in an area very close to the listener, it is necessary to perform signal energy distribution that correctly gives the amount of signal components from the first speaker group with a small contribution, but the first speaker group It is a speaker arranged far from the listener, and it is very difficult to correctly control fine signal energy distribution corresponding to a small contribution degree using a far speaker. As a result, the accuracy of the control of the sound source position in the area close to the listener is reduced, and it becomes difficult for the listener to recognize the correct sound source position.

  The present invention solves the above problem, and by improving the accuracy of the control of the sound source position in the area close to the listener, it enables the recognition of the correct sound source position regardless of the distance from the sound source to the listener, The present invention provides a multi-channel audio playback device that realizes a high sense of realism.

  In addition, when the sound source position control is switched at the boundary between the area far from the listener and the area close to the listener in order to improve the accuracy of the control of the sound source position in the area close to the listener, discontinuity due to the switching occurs, and The listener may feel uncomfortable. The present invention makes it possible to recognize the correct sound source position regardless of the distance from the sound source to the listener by improving the accuracy of the control of the sound source position in the area close to the listener, as well as the area far from the listener and the listener. The present invention provides a multi-channel audio reproduction device that realizes a high sense of realism by smoothing the switching of sound source position control at the boundary of an area close to.

  The multi-channel audio reproduction apparatus of the present invention receives a multi-channel audio signal, determines whether or not a localized sound source exists in the input multi-channel audio signal, and estimates a localized sound source signal when a localized sound source exists. A local sound source estimation unit, a sound source signal separation unit that separates an input multi-channel audio signal into components of a localization sound source signal and a non-localization sound source signal, and a sound source position that calculates a sound source position parameter from the signal components constituting the localization sound source A parameter part, a sound source position determination part for determining whether the sound source position indicated by the calculated sound source position parameter is in an area close to or far from the listener, and an area where the sound source position is far from the listener Playback signal that controls the sound source position indicated by the sound source position parameter A first reproduction signal generation unit for generating, a second reproduction signal generation unit for generating a reproduction signal for controlling the sound source position indicated by the sound source position parameter when the sound source position is in an area close to the listener, A switch unit that switches between the first reproduction signal generation unit and the second reproduction signal generation unit;

  The multi-channel audio reproduction apparatus of the present invention receives a multi-channel audio signal as input, determines whether or not a localized sound source exists in the input multi-channel audio signal, and determines whether or not a localized sound source exists. A sound source position estimation unit, a sound source signal separation unit that separates an input multichannel audio signal into components of a sound source signal and a sound source signal that are not localized, and a sound source position parameter from a signal component that constitutes the sound source A sound source position parameter unit, a sound source position determination unit for determining whether the sound source position indicated by the calculated sound source position parameter is in an area close to or far from the listener, and a sound source position from the listener When the sound source is located in a distant area, the sound source position indicated by the sound source position parameter is controlled again. A first reproduction signal generation unit that generates a signal, and a second reproduction signal generation unit that generates a reproduction signal for controlling the sound source position indicated by the sound source position parameter when the sound source position exists in an area close to the listener A signal distribution unit that distributes the localization sound source and the non-localization sound source signal, and inputs the localization sound source and the non-localization sound source signal only to the first reproduction signal generation unit, or through the signal distribution unit, the first and second A switching unit that switches whether to input to both of the reproduction signal generation units, and an output reproduction signal is generated by adding the output of the first reproduction signal generation unit and the output of the second reproduction signal generation unit.

  By using the present invention, it is possible to control the position of the reproduced sound source with high accuracy regardless of whether the sound source included in the multi-channel audio signal is far or near from the listener, and thus it is possible to realize a high sense of presence. Become.

It is a figure which shows the structure of the multi-channel audio reproduction apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining the process which distributes the signal of a localization sound source to a surrounding speaker and headphones. It is a figure explaining the determination method of the position of a localization sound source. It is a figure explaining the signal processing in the 2nd reproduction | regeneration signal production | generation part which concerns on this Embodiment 1. FIG. It is a figure which shows the structure of the multi-channel audio reproduction apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the conventional reproducing | regenerating apparatus.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a multi-channel audio playback apparatus according to Embodiment 1 of the present invention. Parts having the same functions as those of the processing unit used in the conventional multi-channel audio playback apparatus described above are denoted by the same reference numerals in the drawing, and detailed description thereof is omitted. In FIG. 1, the multi-channel audio playback apparatus of the present invention is provided with a sound source position determination unit 101 and a playback signal generation unit 4 for the first playback in the conventional multi-channel audio playback apparatus shown in FIG. The signal generation unit 102 and the second reproduction signal generation unit 103 are configured to be switched by a switch unit 104.

  The localization sound source estimation unit 1 analyzes the input multi-channel audio signal and determines whether there is a localization sound source whose sound image position to be reproduced exists. When a localization sound source exists, the signal source constituting the localization sound source and other signal components are separated in the sound source signal separation unit 2. The sound source position parameter calculation unit 3 obtains a position where the localization sound source is localized in the reproduction acoustic space from the signal components constituting the localization sound source, and calculates a sound source position parameter. The sound source position determination unit 101 determines, based on the calculated sound source position parameter, whether the position of the localization sound source in the reproduction acoustic space is far from or close to the listener. FIG. 3 is a diagram for explaining a method by which the sound source position determination unit 101 determines whether the position of the localization sound source in the reproduction acoustic space is far from or close to the listener. As described above, the sound source position parameter is given by the direction angle γ of the localization sound source viewed from the listener and the distance r from the listener to the localization sound source. The reproduction acoustic space is divided into an area 302 near the listener and an area 303 far from the listener, with a circumference 301 having a radius r1 centered on the listening point 201 being the center of the listener. A preferable range of the radius r1 is about 0.2 m to 1.0 m. If the distance r to a given localization sound source is r1 or less, the localization sound source exists in an area close to the listener, and conversely if r is larger than r1, the localization sound source exists in an area far from the listener. become. The sound source position determination unit selects the first reproduction signal generation unit when it is determined that the localization sound source is in an area far from the listener, and the first sound source position determination unit is selected when it is determined that the localization sound source is in an area near the listener. The switch unit 104 is controlled so that the second reproduction signal generation unit is selected.

  Next, the operation of the reproduction signal generation unit will be described. The first reproduction signal generation unit selected when it is determined that the localization sound source is in an area far from the listener has the same function as the reproduction signal generation unit in the conventional multi-channel audio reproduction device, After the localization sound source signal input in accordance with the method described above is distributed to each peripheral speaker and headphones, it is synthesized with a non-localization sound source signal and output. The second playback signal generator selected when it is determined that the localization sound source is in an area close to the listener distributes the signal component of the localization sound source only to the headphones and applies signal processing based on human auditory characteristics By doing so, the position of the localization sound source is controlled.

  FIG. 4 is a diagram for explaining signal processing in the second reproduction signal generation unit. The localization sound source 202 is present at a position indicated by a direction angle γ and a distance r with respect to the listening point 201. A signal transmission path from the localization sound source to the left headphones Lh corresponding to the listener's left ear is indicated by an arrow 401, and a signal transmission path from the localization sound source to the right headphones Rh corresponding to the listener's right ear is indicated by an arrow 402. Indicated. That is, the listener is listening to a signal in which the transmission characteristics of both the signal transmission path indicated by the arrow 401 and the transmission path indicated by the arrow 402 are added to the signal emitted from the localization sound source 202. . These transfer characteristics are known as a head related transfer function HRTF (Head Related Transfer Function). By adding the HRTF characteristics to the original sound source signal by signal processing, the transfer is as if the sound source is indicated by the HRTF. You can feel as if you are at the end of the route. Generally, the HRTF is given as an impulse response or an FIR filter coefficient, and the process of adding the HRTF characteristic to the original sound source signal is realized by a convolution operation. That is, the signal component of the localization sound source is X, the HRTF of the transmission path indicated by the arrow 401 is HLh, the HRTF of the transmission path indicated by the arrow 402 is HRh, and the symbol representing the convolution operation is output to the left channel headphones Lh. The signal X_Lh and the output signal X_Rh to the light channel headphone Rh are obtained by the following equations 7 and 8, respectively.

  The HRTF used in signal processing holds the transfer characteristics measured in advance in a storage medium such as a ROM. However, since the characteristics of the HRTF change depending on the position of the localization sound source 202, it is difficult to hold all necessary HRTFs. However, since HRTF can generally be separated into a frequency characteristic depending on the direction angle γ and a gain characteristic depending on the distance from the listening point to the sound source, only the frequency characteristic with respect to the representative direction angle γ is retained. By adjusting the gain according to the distance r from the listening point to the sound source, the storage capacity necessary for holding the HRTF can be reduced.

  Furthermore, the second reproduction signal generation unit 103 distributes the components of the non-localized sound source signal separated in the sound source signal separation unit 2 to each channel of the peripheral speakers. Through the above processing, the localized sound source existing in the area close to the listener is reproduced from the headphones, and the signal components of the other non-localized sound sources are reproduced from the peripheral speakers.

  With the configuration described above, the position of the sound source reproduced using the optimum reproduction signal generation unit can be controlled depending on whether the localized sound source exists in an area close to or far from the listener. As a result, regardless of the distance between the sound source and the listener, it is possible to control the position of the sound source with high accuracy, thereby realizing a high sense of realism.

  In this embodiment, the boundary between the area 302 close to the listener and the area 303 far from the listener is a circle having a radius r1, but a boundary (for example, an ellipse) having a radius r1 that differs depending on the direction angle γ is used. May be. This is because human auditory characteristics differ in sensitivity and sense of distance depending on the direction angle γ. In that case, the sound source position determination unit is configured to determine in which area the localization sound source exists with reference to the sound source position parameters of both the direction angle γ and the distance r.

(Embodiment 2)
FIG. 5 is a diagram showing a configuration of a multi-channel audio playback apparatus according to Embodiment 2 of the present invention. Parts having the same functions as those of the processing unit used in the multi-channel audio reproducing apparatus according to Embodiment 1 of the present invention described above are denoted by the same reference numerals in the drawing, and detailed description thereof is omitted. In the configuration of the second embodiment, a signal distribution unit 105 is added to the reproduction signal generation unit 4 of the multimedia audio reproduction apparatus shown in FIG. 1, and the sound source signal input from the sound source signal separation unit 2 is passed through the switch 104. Whether to input only to the first reproduction signal generation unit 102 or to distribute and input to each of the first reproduction signal generation unit 102 and the second reproduction signal generation unit 103 through the signal distribution unit 105 Switch. Further, the output of the first reproduction signal generator and the output of the second reproduction signal generator are added and then output. The switching control of the switch 104 is the same as in the configuration of the first embodiment of the present invention. When the sound source position determination unit 101 determines that the sound source position exists in an area far from the listener, the first reproduction is performed. If it is determined that the sound source position is in the area close to the listener, the signal generator is switched to the signal distributor. The signal distribution unit 105 distributes the signal component of the localization sound source into two signals according to a predetermined ratio or a ratio based on the distance from the localization sound source to the listener, and each of them is divided into the first reproduction signal generation unit and the first reproduction signal generation unit. 2 to the reproduction signal generation unit. As an example, the ratio based on the distance from the localization sound source to the listener includes a distribution ratio for the first reproduction signal generation unit a, a distribution ratio for the second reproduction signal generation unit b, and from the listener to the localization sound source. The distance is r, and the distance from the listener to the boundary between the area close to the listener and the area far from the listener is r1, and is given by the following equation.

  The sound source signal components that are not localized are input to the first reproduction signal generation unit without being distributed. (The component of the non-localized sound source signal input to the second reproduction signal generation unit is 0.) Each of the first reproduction signal generation unit and the second reproduction signal generation unit follows the procedure described above. Output signals to peripheral speakers and headphones are calculated. The output signal from the first reproduction signal generation unit to the headphones and the output signal from the second reproduction signal generation unit to the headphones are added to generate a final output signal to the headphones. Similarly, the output signal from the first reproduction signal generation unit to each peripheral speaker and the output signal from the second reproduction signal generation unit to each peripheral speaker are added to become the final output signal to the peripheral speaker. It is obvious that both the first reproduction signal generation unit and the second reproduction signal generation unit are not given an input signal, or if the input signal is 0, the output signal becomes 0.

  With the configuration described above, the position of the sound source reproduced using the optimum reproduction signal generator is controlled depending on whether the localization sound source exists in an area close to or far from the listener, and the listener The switching of sound source position control at the boundary between the area far from the listener and the area close to the listener can be smoothed. As a result, regardless of the distance between the sound source and the listener, it is possible to control the position of the sound source with high accuracy, thereby realizing a high sense of realism.

  Note that (1) Each of the above devices is specifically a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. A computer program is stored in the RAM or hard disk unit. Each device achieves its functions by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

  (2) A part or all of the constituent elements constituting each of the above-described devices may be configured by one system LSI (Large Scale Integration). The system LSI is an ultra-multifunctional LSI manufactured by integrating a plurality of components on a single chip, and specifically, a computer system including a microprocessor, ROM, RAM, and the like. . A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating according to the computer program.

  (3) Part or all of the constituent elements constituting each of the above devices may be configured from an IC card that can be attached to and detached from each device or a single module. The IC card or the module is a computer system including a microprocessor, a ROM, a RAM, and the like. The IC card or the module may include the super multifunctional LSI described above. The IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

  (4) The present invention may be the method described above. Further, the present invention may be a computer program that realizes these methods by a computer, or may be a digital signal composed of the computer program.

  The present invention also provides a computer-readable recording medium such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray Disc). ), Recorded in a semiconductor memory or the like. Further, the digital signal may be recorded on these recording media.

  The present invention may also be such that the computer program or the digital signal is transmitted via an electric communication line, a wireless or wired communication line, a network represented by the Internet, data broadcasting, or the like.

  The present invention may be a computer system including a microprocessor and a memory, wherein the memory stores the computer program, and the microprocessor operates according to the computer program.

  In addition, the program or the digital signal is recorded on the recording medium and transferred, or the program or the digital signal is transferred via the network or the like, and executed by another independent computer system. It is good.

  (5) The above embodiment and the above modifications may be combined.

  The present invention can be applied to a multi-channel audio reproducing apparatus and the like that can recognize the correct sound source position regardless of the distance from the sound source to the listener and realize a high sense of reality.

DESCRIPTION OF SYMBOLS 1 Localization sound source estimation part 2 Sound source signal separation part 3 Sound source position parameter calculation part 4 Playback signal generation part 5 Left channel speaker (L)
6 Center channel speaker (C)
7 Light channel speaker (R)
8 Surround light channel speakers (Rs)
9 Surround Left Channel Speaker (Ls)
10 Left channel headphones (Lh)
11 Light channel headphones (Rh)
DESCRIPTION OF SYMBOLS 101 Sound source position determination part 102 1st reproduction | regeneration signal generation part 103 2nd reproduction | regeneration signal generation part 104 Switch part 105 Signal distribution part 201 Listening point 202 Localization sound source 203 Left channel speaker (L)
204 Center channel speaker (C)
205 Light channel speaker (R)
206 Surround Light Channel Speaker (Rs)
207 Surround Left Channel Speaker (Ls)
208 Left channel headphones (Lh)
209 Light channel headphones (Rh)
301 Circumference (boundary that divides playback acoustic space)
302 Area close to the listener 303 Area far from the listener 401, 402 Arrow

Claims (10)

A multi-channel audio reproduction device that reproduces a multi-channel audio signal using a first speaker group arranged near the listener and a second speaker group arranged near the ear,
A localization source estimation unit for estimating a localization source included in the input multi-channel signal;
A sound source signal separation unit that separates an input multi-channel signal into a signal component of a localization sound source and a component of a sound source signal other than the localization source when a localization sound source exists;
A sound source position parameter calculation unit for calculating and parameterizing the position of the localization sound source;
A sound source position determination unit that determines whether the localization sound source exists in an area close to the listener or in a distant area based on the sound source position parameter;
A first reproduction signal generation unit that generates a reproduction signal for controlling the sound source position when the localization sound source exists in an area far from the listener;
A second reproduction signal generation unit that generates a reproduction signal for controlling the sound source position when the localization sound source exists in an area close to the listener;
A multi-channel audio reproduction device comprising: a switch unit that switches between a first reproduction signal generation unit and a second reproduction signal generation unit according to a determination result of a sound source position determination unit. The sound source position parameter is the direction angle γ and the distance r of the localization sound source with respect to the listener, and the boundary between the area close to the listener and the area far from the listener is defined by a distance r1 predetermined with respect to the direction angle γ. The multi-channel audio reproduction device according to claim 1, wherein the sound source position determination unit determines a sound source position by comparing the distance r and the distance r1 at the direction angle γ. The first reproduction signal generation unit reproduces the distribution of the signal energy of the localization sound source between the first speaker group and the second speaker group according to the direction angle γ and the distance r to the listener. Control the sound source position
The second reproduction signal generation unit controls a sound source position to be reproduced by outputting a sound source signal to which a transfer characteristic from a sound source to a listener is added to the second speaker group. Multi-channel audio playback device. The multi-channel audio reproduction device according to claim 2, wherein the distance r1 is a value determined in accordance with the direction angle γ in accordance with human auditory characteristics. The multi-channel audio reproducing apparatus according to claim 2, wherein the distance r1 is determined in a range of about 0.2 m to 1.0 m. A multi-channel audio reproduction device that reproduces a multi-channel audio signal using a first speaker group arranged near the listener and a second speaker group arranged near the ear,
A localization source estimation unit for estimating a localization source included in the input multi-channel signal;
A sound source signal separation unit that separates an input multi-channel signal into a signal component of a localization sound source and a component of a sound source signal other than the localization source when a localization sound source exists;
A sound source position parameter calculation unit for calculating and parameterizing the position of the localization sound source;
A sound source position determination unit that determines whether the localization sound source exists in an area close to the listener or in a distant area based on the sound source position parameter;
A first reproduction signal generation unit that generates a reproduction signal for controlling the sound source position when the localization sound source exists in an area far from the listener;
A second reproduction signal generation unit that generates a reproduction signal for controlling the sound source position when the localization sound source exists in an area close to the listener;
A signal distribution unit that distributes the signal component of the localization sound source and the other non-localization sound source signal components;
According to the determination result of the sound source position determination unit, the signal component of the localization sound source and the other non-localization sound source signal components are input only to the first reproduction signal generation unit, or the first reproduction signal is transmitted through the signal distribution unit. A switch unit for switching whether to input to both the generation unit and the second reproduction signal generation unit,
A multi-channel audio reproduction device that generates an output reproduction signal by adding the output of a first reproduction signal generation unit and the output of a second reproduction signal generation unit. The signal distribution unit distributes the signal component of the localization sound source into two signals according to a predetermined ratio, and inputs each of the signals to the first reproduction signal generation unit and the second reproduction signal generation unit. A multi-channel audio playback apparatus according to claim 1. The signal distribution unit distributes the signal component of the localization sound source into two signals according to a ratio based on the distance from the localization sound source to the listener, and the first reproduction signal generation unit and the second reproduction signal generation unit, respectively. The multi-channel audio reproducing apparatus according to claim 6. A multi-channel audio reproduction method for reproducing a multi-channel audio signal using a first speaker group arranged in the vicinity of a listener and a second speaker group arranged in the vicinity of the ear,
Estimating a localization sound source included in the input multichannel signal;
Separating the input multichannel signal into a signal component of the localization sound source and a component of the other signal when a localization sound source exists;
Calculating the position of the localization sound source and converting it to a sound source position parameter;
Based on the sound source position parameter, performing a sound source position determination whether the localization sound source exists in an area close to the listener or in a distant area;
A first reproduction signal generation step of generating a reproduction signal for controlling the sound source position when the localization sound source is in an area far from the listener;
A second reproduction signal generation step of generating a reproduction signal for controlling the sound source position when the localization sound source is present in an area close to the listener;
A multi-channel audio reproduction method comprising a step of switching between a first reproduction signal generation step and a second reproduction signal generation step according to a determination result of a sound source position determination step.   A program for causing a computer to execute each step included in the multi-channel audio reproduction method according to claim 9.

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