JPH1070798A - Three-dimensional sound reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the same sound field effect as that obtained in a three- dimensional sound space only by two speakers without using many speakers. SOLUTION: A sound effect giving device 1 is constituted by cascading a sound field effect giving part 10 and a crosstalk cancellation part 20. The sound field effect giving part 10 gives specific three-dimensional sound field effect to an input sound signal to generate sound signals corresponding to a right and a left channel. The crosstalk cancellation part 20 performs arithmetic processing for the sound signals and outputs the processed signals to the speakers so that when the sound signals corresponding to the right and left channels are outputted from the two speakers right in front of a listener, they reaches the right and left ears of the listener without causing any crosstalk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional sound reproducing apparatus for reproducing sound signals by adding sound field effects corresponding to various three-dimensional sound spaces such as concert halls to sound signals.

[0002]

2. Description of the Related Art In a three-dimensional acoustic space such as a concert hall, a sound emitted by a player or the like is reflected at various places such as a wall of the hall and transmitted as reverberant sounds from various directions to a listener's ear. Is done. And the reverberation sounds from these various directions are a source of producing a sense of reality peculiar to the three-dimensional acoustic space. There is a so-called multi-speaker system as an acoustic system that faithfully reproduces the realism of a performance in such a three-dimensional acoustic space. According to such a multi-speaker system, a sound having an arbitrary sound image position can be reproduced by generating sounds from a large number of speakers arranged so as to surround a listener and controlling the volume of the sounds. Therefore, it is possible to provide the listener with the impression that reverberation sounds come from various directions, that is, the same realistic feeling as obtained in a three-dimensional acoustic space such as a concert hall.

[0003]

The above-mentioned multi-speaker system is an excellent system in terms of sound field effect. However, since it is a large-scale system using a large number of speakers, the system itself is expensive. Will be. Also, when using a multi-speaker system,
Since each speaker must be arranged at a predetermined position, a sound room having a certain size is required. In addition, since the multi-speaker system controls the sound image position based on the balance of the volume of each speaker, if the balance of the volume is out of balance, the impression that sound is output from the speakers will inevitably increase. For this reason, there is a problem that it is difficult to perform control for sound reproduction with a sense of reality.

[0004] The present invention has been made in view of the circumstances described above, and has been developed without using many speakers.
It is an object of the present invention to provide a three-dimensional sound reproducing device that can obtain a sound field effect equivalent to that obtained in a three-dimensional sound space by using only speakers.

[0005]

The invention according to claim 1 is
Sound field effect applying means for generating sound signals of left and right two channels by applying a predetermined three-dimensional sound field effect to an input sound signal; And crosstalk canceling means for performing arithmetic processing on each of the acoustic signals so that the sound signals reach the left and right ears of the listener without crosstalk when emitted from the speakers. The gist is a three-dimensional sound reproducing device.

According to a second aspect of the present invention, when the sound field effect applying means generates an impulse sound from a virtual point in a three-dimensional acoustic space, each reverberant sound wave detected at two points in the acoustic space is generated. 2. The three-dimensional sound reproducing apparatus according to claim 1, wherein the filter signals are obtained by sampling each shape and convolving each filter coefficient sequence with the input sound signal to generate the left and right two-channel sound signals. Is the gist.

According to a third aspect of the present invention, the two points in the acoustic space are positions corresponding to the left and right ears of a dummy head arranged in the acoustic space, and each of the filter coefficient sequences convolved with an input signal. The present invention provides a three-dimensional sound reproducing apparatus according to claim 2, wherein the apparatus includes a component corresponding to a head-related transfer function.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described for easier understanding of the present invention. These embodiments show one aspect of the present invention, and do not limit the present invention, and can be arbitrarily changed within the scope of the present invention.

The three-dimensional sound reproducing apparatus according to the present invention uses only two speakers arranged in front of a listener to reproduce sound with a sound field effect corresponding to an arbitrary three-dimensional sound space. It is provided to the listener. FIG. 1 is a block diagram showing a configuration of a sound field effect imparting device 1 according to one embodiment.

The sound field effect imparting device 1 includes a sound field effect imparting section 10 for imparting a sound field effect corresponding to a predetermined three-dimensional acoustic space to an input audio signal to be reproduced, and a sound field effect imparting section. A cascade connection is made between a two-channel sound signal obtained from 10 and a crosstalk canceling unit 20 for performing processing for canceling crosstalk, as shown in the figure. Then, the two-channel sound signals obtained from the crosstalk canceling unit 20 are supplied to left and right two-channel speakers (not shown) arranged in front of the listener, respectively, to provide sound with a predetermined sound field effect. Is provided to the listener.

The sound field effect imparting section 10 is provided with a FIR (Finite I)
mpulse Response (finite impulse response) filter 11
And 12. These FIR filters 11 and 12 perform an operation process of convolving time-series sample data of each reverberation sound waveform collected at two points in a predetermined three-dimensional sound space into an input audio signal (time-series sample data) as a filter coefficient sequence. Is what you do.

Each filter coefficient sequence used for the convolution operation of the FIR filters 11 and 12 is collected, for example, in an environment as shown in FIG. In FIG. 2, reference numeral 100 denotes a concert hall as a three-dimensional acoustic space. As shown in FIG. 2, a dummy head 101 is arranged at the center of the audience seat in the concert hall 100. The dummy head 101 imitates a human head, and a pair of microphones 101L and 101R corresponding to the left and right ears of the human are provided at respective positions on both the left and right sides. On the other hand, on a stage 102 in front of the concert hall 100, a sound source including two speakers 103 and 104 is arranged. These speakers simulate a musical instrument or a vocalist emitting sound on the stage 102. Conditions such as the number of speakers used and the attitude of each speaker may be selected in consideration of the radiation characteristics of the sound of a sound source such as a musical instrument to be simulated. In this example, two speakers are used to radiate the sound in all directions (that is, to make the radiation characteristic of the sound non-directional).

In such a device configuration, the speaker 1
An impulse sound is generated from a sound source consisting of 03 and 104. This impulse sound is indicated by arrows 105, 105,.
The light propagates along a number of paths exemplified by, and is reflected by the walls and the like of the concert hall 100 and reaches the microphones 101L and 101R of the dummy head 101.
Then, each of the microphones 101L and 101R collects a reverberation sound waveform obtained by synthesizing reverberation sounds from many directions.

Each reverberant sound waveform (impulse response waveform) collected by the microphones 101L and 101R in this manner is sampled at a predetermined sampling cycle. Then, the reverberation sound waveform sample data sequence obtained by the microphone 101L is used as a filter coefficient sequence of the FIR filter 11, and the reverberation sound waveform sample data sequence obtained by the microphone 101R is converted to the FIR filter.
It is used as a filter coefficient sequence of the filter 12.

In the configuration shown in FIG. 1, the FIR filters 11 and 12 convolve these filter coefficient sequences with the input audio signal.
The input audio signal is transmitted to speakers 103 and 10 in FIG.
Thus, an acoustic signal having exactly the same waveform as each reverberant sound that would be collected by the microphones 101L and 101R when output as a sound from No. 4 is obtained. The above is the function of the sound field effect imparting unit.

The crosstalk canceling section 20 includes four filters 21 to 24 and two subtracters 25 and 26, and as described above, the sound field effect applying section 1
A process for preventing the occurrence of crosstalk is performed on the audio signals of two channels output from 0. By providing the crosstalk canceling section 20, each acoustic signal obtained from the sound field effect applying section 10 can be transmitted to the left and right ears of the listener without causing crosstalk. That is, as described above, in the present embodiment, three-dimensional sound reproduction is performed by using two speakers. However, by employing the crosstalk canceling unit 20, regardless of the distance between the speakers and the listener. Thus, each sound corresponding to the two-channel sound signal output from the sound field effect imparting section 10 can be transmitted independently to the left and right ears of the listener. Therefore, it is possible to provide the listener with exactly the same sense of realism as obtained in a three-dimensional acoustic space such as a concert hall. The details of the function of the crosstalk cancel unit 20 will be described later.

The sound field effect imparting device 1 has been described above. In addition, the use of the sound image localization device 2 illustrated in FIG. 3 enables a more realistic three-dimensional sound reproduction. The sound image localization device 2 includes a sound image localization unit 30 that assigns an arbitrary sound image position to acoustic signals of left and right two channels.
And a crosstalk canceling unit 20 having exactly the same configuration as that used in the sound field effect device 1 in cascade connection as shown in the figure.

Here, the function of the crosstalk cancel unit 20 will be described with reference to FIGS. As described above, in the present embodiment, three-dimensional sound reproduction is performed using only two speakers arranged in front of the listener. FIG. 4 illustrates this state, in which 201L and 201R indicate left and right speakers used in the present embodiment, M indicates a listener's head, and EL and ER indicate left and right ears of the listener.

As shown in FIG.
The sound emitted from (201R) is transmitted to the listener's ear EL (ER) by following each path indicated by a solid line, and the sound emitted from the listener's ear ER is determined by following the path indicated by a broken line.
(EL). The transmission of the latter sound is called crosstalk.

In sound reproduction, in order to obtain the desired sound field effect, the crosstalk is eliminated and the speaker 20 is used.
Each sound emitted from 1L (201R) is a listener's ear EL (E
R) only. However, since the speaker must be arranged at a certain distance from the listener's ear, crosstalk is an unavoidable problem beyond the use of the speaker. Therefore, a countermeasure is taken to effectively eliminate the crosstalk by supplying the left and right speakers 201L and 201R with predetermined processing applied to the audio signals of the two channels to be originally reproduced. The means for that is the crosstalk canceling unit 20 in FIG. 3 or FIG.

FIG. 5 is a diagram for explaining the function of the crosstalk cancel unit 20. In this figure, X and Y represent two-channel left and right sound signals output from the sound image localization unit 30 in FIG. 3 or the sound field effect imparting unit 10 in FIG. Represents the transfer function. HLL is the left speaker 201
HRR is a transfer function of a path from L to the listener's left ear EL, and HRR is a transfer function of a path from the right speaker 201R to the listener's right ear ER. HLR and HRL represent transfer functions of a path from the left speaker 201L to the right ear ER of the listener and a path from the right speaker 201R to the left ear EL of the listener, that is, transfer functions of respective paths that cause crosstalk. I have.

According to the crosstalk cancel unit 20,
By appropriately selecting the transfer functions A to D of the filters 21 to 24, it is possible to cancel the crosstalk component from the sounds heard by the left and right ears of the listener. Specifically, it is as follows.

First, as shown in FIG. 6, only a signal transmission system corresponding to the left channel acoustic signal X will be considered.

The sound signal X is supplied to the filter 21 and the speaker 2
01L and the path of the transfer function HLL, the sound a is transmitted as the sound a to the left ear EL.
2. The sound b is transmitted to the left ear EL through the path of the speaker 201R and the transfer function HRL.
These sounds a and b can be expressed as follows. a = A · HLL · X (1) b = B · HRL · X (2)

Here, in order to transmit only the sound corresponding to the acoustic signal X to the left ear EL of the listener, a + b = A.HLL.X + B.HRL.X = X must be satisfied. No. Therefore, transfer functions A and B
Must meet the following conditions: A · HLL + B · HRL = 1 (4)

On the other hand, the acoustic signal X passes through the path of the filter 21, the speaker 201L and the transfer function HLR, and is transmitted to the right ear ER as a sound a ', and is further transmitted to the filter 22, the speaker 201R and the transfer function HRR. The sound b ′ is transmitted to the right ear ER through the route. These sounds a 'and b' can be expressed as follows. a ′ = A · HLR · X (5) b ′ = B · HRR · X (6)

Here, in order to eliminate the crosstalk,
Eliminating the transmission of the acoustic signal X to the right ear ER of the listener, that is, the following condition must be satisfied. a ′ + b ′ = A · HLR · X + B · HRR · X = 0 (7) Therefore, the transfer functions A and B must satisfy the following conditions. A · HLR + B · HRR = 0 (8)

Therefore, A = − obtained from the above equation (8)
By substituting B · HRR / HLR into the above equation (4), −B · (HRR / HLR) · HLL + B · HRL = 1 (9) By solving this for B, B = −HLR / ( HLL · HRR−HLR · HRL) (10) By substituting B into equation (8) and solving for A, A = HRR / (HLL · HRR−HLR · HRL) (11) is obtained.

By using filters having such transfer coefficients A and B as the filters 21 and 22,
The sound corresponding to the sound signal X of the left channel is output to the listener's left ear EL.
It can only be communicated to them.

Although the above description has been made with reference to the case of the left channel acoustic signal X as an example, the same method can be applied to the right channel acoustic signal Y, and the transfer functions C, C The following is obtained as D: C = -HRL / (HLL / HRR-HLR / HRL) (12) D = HLL / (HLL / HRR-HLR / HRL) (13)

When the speakers are arranged symmetrically with respect to the listener, HLL = HRR and HLR = HRL hold, so that the transfer functions A,
The filters 21 to 24 may be designed based on B, C, and D (in this case, A = D, B = C). The above is the details of the function of the crosstalk canceling unit 20 in the present embodiment.

Next, the sound image localization unit 30 in FIG. 3 will be described. In the present embodiment, as illustrated in FIG. 4, the sound signals are generated by the speakers 201 </ b> L and 201 </ b> R disposed in front of the listener, and the sound image localization unit 30 generates the sound corresponding to the sound signal as if This makes it possible for the listener to hear the sound as if it were being sounded from speakers 202L and 202R (virtual speakers that are not actually used).

For the sake of simplicity, a case where the sound image of the left-channel sound signal is localized at the position of the virtual speaker 202L in FIG. 4 will be described. FIG. 7 shows a virtual speaker 202L.
FIG. 3 illustrates the positional relationship between the left and right ears EL and ER of the listener. In this example, the virtual speaker 202L is in a direction of an angle θ from the front of the listener M, and the virtual speaker 20L
The sound emitted from 2L is transmitted to the left ear EL along the path of the transfer function HL, and transmitted to the right ear ER along the path of the transfer function HR.

In order to localize the sound image of the left-channel sound signal at the position of the virtual speaker 202L, filters 31 and 32 having transfer functions corresponding to the transfer functions HL and HR are used. By providing the left channel sound signal to these filters 31 and 32, when the sound signal is output as sound from the virtual speaker 202L in FIG.
An acoustic signal having exactly the same waveform as the sound heard by L and ER is obtained from each filter.

The sound signals output from the filters are passed through the crosstalk canceling section 20 to the left and right speakers 20.
1L and 201R (FIG. 3). Therefore, regardless of the distance between the speakers 201L and 201R and the listener, each sound corresponding to the sound signal of each channel output from each filter of the sound image localization unit 30 is independently transmitted to the left and right ears of the listener. The sound image of the sound heard by the listener can be accurately localized at the position of the virtual speaker 202L.

While the above description has been made with reference to the left channel acoustic signal as an example, the same applies to the right channel acoustic signal.
A virtual speaker 20 whose sound image is illustrated in FIG.
A transfer function for localizing at the position of 2R is obtained in advance, and the filters 33 and 3 having such a transfer function are used.
4 are used.

Next, a specific application example of the three-dimensional sound reproducing apparatus according to the embodiment described above will be described. First, FIG. 8 shows that the input sound signal is supplied to the sound field effect device 1 (FIG. 1) described above, and the left and right two channel sound signals obtained from the sound field effect device 1 are passed through the power amplifiers 301L and 301R. In this way, the power is supplied to the speakers 201L and 201R located in front of the listener M. It is a typical example of a three-dimensional sound reproducing device using the sound field effect device 1. According to this device, for the listener M,
As shown by the arrows, it is possible to give an impression as if reverberant sounds are coming from various directions, and it is possible to provide three-dimensional sound full of a sense of reality.

Next, an application example of the three-dimensional sound reproducing apparatus according to the present embodiment to an electronic musical instrument will be described with reference to FIGS. In a conventional electronic musical instrument, as shown in FIG.
Left and right speakers 201L and 201R are provided at positions on both sides of the electronic musical instrument, and a sound having a spatial expanse is generated by adjusting the balance of the volume when sound is output from these speakers. In order to generate a sound having a spatial spread by adjusting the volume balance, the speakers 201L and 201R need to be provided at positions separated by a certain distance or more. There is a problem that the dimension in the direction becomes long.

If the sound field effect device 1 or the sound image localization device 2 described above is used, the spatial expansion is achieved by the two speakers arranged in front of the listener (the player of the electronic musical instrument in this application example). Therefore, as shown in FIG. 10, two speakers 201L and 201R may be provided in the center of the electronic musical instrument, and the width of the electronic musical instrument can be reduced. .

FIG. 11 shows a circuit configuration example when this embodiment is applied to an electronic musical instrument. In the example shown in this figure, sound signals of left and right two channels are generated by the sound source 41 in accordance with the keyboard operation performed by the player, and these are input to the sound image localization apparatus 2 (see FIG. 3) already described. At the same time, the sum of these by the adder 42 is input to the sound field effect device 1 (see FIG. 1) described above.

The roles played by the sound image localization device 2 and the sound field effect device 1 are as described above, and the sound image localization device 2 and the sound field effect device 1 correspond to the left and right two-channel sound signals provided with the predetermined sound image positions and the predetermined three-dimensional sound space. The left and right two-channel sound signals to which the sound field effect is applied are output. Then, the two left and right channel acoustic signals obtained from the sound image localization device 2 and the two left and right channel acoustic signals obtained from the sound field effect device 1 are added by the adders 43 and 44 between the same channels. Output signals of the adders 43 and 44 are supplied to the speakers 201L and 201R via the power amplifiers 301L and 301R, respectively. As a result,
The sound having the predetermined sound image position and the sound to which the sound field effect of the predetermined three-dimensional sound space is added are heard by the performer.

In the circuit configuration example shown in FIG. 11, the sound field effect device 1 and the sound image localization device 2 each have a crosstalk canceling unit 20 at the latter stage of the circuit, as is clear from FIGS. Therefore, these may be used in common. Specifically, the two outputs of the sound field effect imparting unit 10 of the sound field effect device 1 and the two outputs of the sound image localization unit 30 of the sound image localization device 2 are added to the adder 4 shown in FIG.
3 and 44, and these two outputs are added to the crosstalk cancel unit 2 described above.
The input is input to a single crosstalk canceling unit having the same configuration (same filter coefficient) as 0, and two outputs of the single crosstalk canceling unit are supplied to power amplifiers 301L and 301R shown in FIG. Thus, the circuit scale can be reduced.

This application example can be said to be one of the applications to which the present embodiment is easily applied. That is, usually, the performer faces the two speakers 201L and 201R and performs the performance while being away from the electronic musical instrument by a distance that is not inconvenient for the performance.
It is considered that the positional relationship between the player and the left and right ears of the player is substantially fixed. Therefore, each signal processing of the sound field effect device 1 and the sound image localization device 2 on the premise of such a positional relationship becomes just appropriate, and the provision of the sound field effect and the sound image localization are performed as expected.

FIG. 12 shows an example in which the present embodiment is applied to a piano practice classroom. As shown in this figure, a microphone 52 for collecting piano performance sounds is arranged below the sound board of the piano 51. Also,
The left and right speakers 201 are located on the upper surface or above the piano 51 and in a position substantially in front of the piano player.
L and 201R are arranged. The acoustic signal obtained by the microphone 52 is input to the already described sound field effect device 1 (see FIG. 1) via the amplifier 53. The left and right two-channel sound signals obtained from the sound field effect device 1 are power amplifiers 301L or 301R.
Are output from the speakers 201L and 201R respectively. As a result, the sound obtained by adding the sound field effect of the three-dimensional sound space such as a concert hall to the piano performance sound is heard by the piano player. The distance between the speakers 201L and 201R and the piano player can be appropriately adjusted. Symbol S in FIG. 12 illustrates an area where a sound field is formed. The piano player will feel as if he / she is inside a concert hall or the like.

FIG. 13 shows an example in which the present embodiment is applied to a music practice room in which various musical instruments such as saxophones and flutes are played and vocals are performed. The configuration of the device is exactly the same as that shown in FIG. In this example, the performers of each instrument are speakers 201L and 20L.
By playing (or singing) in front of the 1R, the sound spread as indicated by the area S is felt as a sound field feeling.

Next, FIG. 14 shows an example in which the present embodiment is applied to a karaoke room. As shown in the figure, a microphone 61 and a video monitor 64 are installed in front of the singer. In the video monitor 64,
Based on the video output information supplied from the karaoke system 63, lyrics and the like are displayed. The acoustic signal of the vocal sound collected from the singer by the microphone 61 is supplied to the karaoke system 63, while being supplied to the sound field effect device 1 via the amplifier 62. As a result, the sound field effect device 1 outputs vocal sound signals of two channels on the left and right sides to which a sound field effect corresponding to the three-dimensional sound space is given. In the karaoke system 63, the sound signals of the accompaniment sound composed of two channels on the left and right are reproduced in accordance with the progress of the music, and these sound signals are supplied to the sound image localization device 2.
As a result, the sound image localization device 2 outputs the acoustic signals of the accompaniment sounds of the two left and right channels to which the predetermined sound image positions are assigned.

Each of the acoustic signals output from the sound field effect device 1 and the sound image localization device 2 is added to the same channel by adders 43 and 44. The output signal of each of the adders 43 and 44 is output to the power amplifier 301L or 30L.
The singers hear the accompaniment sound having a predetermined sound image position and the vocal sound provided with the sound field effect of the predetermined three-dimensional sound space, which are supplied to the speakers 201L and 201R via the respective 1Rs. In FIG. 14, reference numeral S1 denotes an area where a vocal sound field is formed,
The symbol S2 exemplifies an area where a sound field of an accompaniment sound is formed. The area for forming the sound field may be appropriately determined in accordance with the intended use.

[0048]

As described above, according to the present invention, by applying a predetermined three-dimensional sound field effect to an input sound signal, a sound field effect for generating left and right two-channel sound signals is provided. Means, and when the sound signals of the respective channels are respectively emitted from two speakers positioned in front of the listener, the respective sound signals are transmitted to the left and right ears of the listener without causing crosstalk. Since the crosstalk canceling means for performing the arithmetic processing is provided, it is possible to obtain a sound field effect equivalent to that obtained in a three-dimensional acoustic space by using only two speakers without using many speakers. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a sound field effect imparting device in a three-dimensional sound reproducing device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a function of the sound field effect giving device.

FIG. 3 is a block diagram illustrating a configuration of a sound image localization device according to the first embodiment.

FIG. 4 is a diagram illustrating functions of the sound image localization apparatus.

FIG. 5 is a diagram illustrating a function of a crosstalk canceling unit in the embodiment.

FIG. 6 is a diagram illustrating a function of a crosstalk canceling unit according to the first embodiment.

FIG. 7 is a diagram illustrating functions of the sound image localization device.

FIG. 8 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 9 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 10 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 11 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 12 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 13 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

FIG. 14 is a diagram showing an application example of the three-dimensional sound reproduction device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sound field effect device (3D sound reproduction device), 10 ... Sound field effect imparting part (sound field effect imparting means), 20 ... Crosstalk canceling part (crosstalk canceling means).

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akio Takahashi 10-1 Nakazawacho, Hamamatsu City, Shizuoka Prefecture Yamaha Corporation

Claims (3)

[Claims] 1. A sound field effect providing means for generating two left and right channel sound signals by applying a predetermined three-dimensional sound field effect to an input sound signal; Crosstalk canceling means for performing arithmetic processing on each of the acoustic signals so that the two speakers reach the left and right ears of the listener without crosstalk when emitted from two speakers located in front of each other. A three-dimensional sound reproducing device characterized by the above-mentioned. 2. The sound field effect imparting means samples each reverberant sound waveform detected at two points in a sound space when an impulse sound is generated from a virtual point in a three-dimensional sound space. 3. The three-dimensional sound reproduction apparatus according to claim 1, wherein the left and right two-channel sound signals are generated by convolving each of the filter coefficient sequences obtained by the above with the input sound signal. 3. The two points in the acoustic space are positions corresponding to left and right ears of a dummy head disposed in the acoustic space, and each of the filter coefficient sequences convolved with an input signal is:
3. The three-dimensional sound reproducing apparatus according to claim 2, wherein the three-dimensional sound reproducing apparatus includes a component corresponding to a head-related transfer function.