JP2009077379A - Stereoscopic sound reproduction equipment, stereophonic sound reproduction method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reproduce stereoscopic sound signals constituted of a plurality of layers disposed in the vertical direction, with each of the plurality of layers comprising a plurality of channels, into a sound field with speakers that are fewer in number than the channels of the sound signals. <P>SOLUTION: Of 22.2 channels, 13.2 channels, including middle layer 10 channels, low layer 3 channels, and LFE2 channels, are assigned to 2n pieces of speakers which are disposed in the circumferential direction with a horizontal surface of right and left ears as a middle layer. For upper layer 9 channels, one or more channels are assigned to one or more pieces of ceiling speakers, with the rest channel being assigned to 2n pieces of speakers of middle layer (2n+1<22). The stereoscopic sound signals of the 22.2 channels are output to 2n+1 pieces or more of speakers, after they undergo spatial sound field treatment such that a virtual sound source of 22.2 channels will be heard from that direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stereophonic sound reproducing apparatus that is constituted by a plurality of layers arranged in the vertical direction and that reproduces a stereoacoustic signal in which each of the plurality of layers is constituted by a plurality of channels, particularly for super high vision. The present invention relates to a three-dimensional sound reproduction apparatus, a three-dimensional sound reproduction method, and a computer program that are suitable for reproducing a 22.2 channel sound signal with less speakers.

  In recent years, with the widespread use of DVD and the like, a surround system using multi-channels has permeated and sound reproduction with a sense of reality is possible. In general households, six speakers are installed for the front, right front, left front, right rear, left rear, and bass output of the listener (usually a subwoofer speaker placed in front) 5.1ch or further back The use of 7.1ch surround with two in the center is increasing. These can reproduce sound effects with a sense of presence by distributing audio signals recorded in multi-channel to 5 channels or 7 channels.

  By the way, the multi-channel method such as 5.1ch or 7.1ch described above is two-dimensional sound in which each speaker is arranged around the viewer on one horizontal plane (horizontal plane of left and right ears). By the way, research results have been obtained that sound sensations can be increased by sound waves coming from above. However, the above-described conventional surround system can reproduce the surround effect in which the sound image is dropped at the height of the speaker and is allocated at 360 degrees in the plane direction, but the surround effect in the vertical direction is not considered. While the actual sound field is a celestial sphere that surrounds the listener, the acoustic signal reproduced by these systems is planar, and the sound that is actually heard from above is lower than the actual sound reproduced. There was a sense of incongruity that the sound was heard, or in fact, the sound that was heard spreading in the vertical direction could feel unsatisfactory that the reproduced sound would no longer spread.

  In order to solve this, there is known a stereophonic sound in which the vertical direction is divided into a plurality of layers and a plurality of speakers are arranged around the viewer in each layer. As a 3D sound system, the 22.2 channel system for Super Hi-Vision was disclosed in Non-Patent Document 1 below, and was also exhibited at the 2005 Aichi Expo. In order to reproduce the three-dimensional sound in the large hall, the channel and speaker configuration of this system is installed near the ceiling (middle channel (10 channels, 360 °)) on the horizontal plane near the center of the screen height. The upper layer (9 channels, 360 °) and the lower layer (3 channels, front only) installed on the floor surface are configured by a three-layer speaker system. The LFE is also composed of 2-channel stereo.

The upper and lower speakers in the 22.2 channel system play an important role in sound image localization and sound image movement in the vertical direction, and the upper speakers aim at reproducing natural and high-quality acoustic space and expanding the optimum listening range. is there. Also, in recent years, transmission capacity and media capacity have increased due to technological advances, and there has been a movement of HDA (High Definition Audio), and it is assumed that broadcasting in 22.2 channels will be realized in the near future. Non-Patent Document 1 below discloses a 10.2 channel system (no lower layer) of 8 layers of intermediate layer + 2 channels of upper layer + 2 channels of LFE as another stereophonic system. As another stereophonic sound system, a 19.2 channel system such as an intermediate layer 10 channel + upper layer 9 channel + LFE 2 channel with the lower 3 channels of the 22.2 channel system omitted is known.
JAS Journal 2005 Vo1. 45 No. 1 “Stereoscopic Sound and Stereoscopic Video-Part 1 Stereophonic Sound”, p19-p22

  Now, in order to reproduce the three-dimensional sound by this system at home, it is necessary to reproduce an acoustic signal having a much larger number of channels than various conventional 5.1 surround systems from various places such as the rear wall and ceiling. is there. However, in the conventional 5.1 surround system and the sound image localization processing apparatus targeted for two sets of speakers, there is a problem that it is difficult to reproduce the upper sound field. In particular, sound field reproduction equivalent to the sound field created by the upper layer (9 channels) is expected.

  The present invention has been made in view of the above circumstances, and is composed of a plurality of layers arranged in the vertical direction, and a sound field of a stereophonic sound signal in which each of the plurality of layers is composed of a plurality of channels. It is an object of the present invention to provide a three-dimensional sound reproduction apparatus, a three-dimensional sound reproduction method, and a computer program that can be reproduced with fewer speakers.

In order to achieve the above-described object, the stereophonic sound reproducing device of the present invention has an upper layer formed by dividing the reproduction space in the height direction in a reproduction space for reproducing a stereoacoustic signal composed of a plurality of channels, In the stereophonic sound reproducing apparatus that reproduces the stereophonic signal with the middle part being the middle layer and the lower part being the lower layer,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer Means for distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. A spatial sound field that is processed by a spatial sound field so that a virtual sound source of each channel of the stereophonic signal can be heard from that direction and is output to the first and second speaker groups when reproduced by a group. Processing means,
It is characterized by having.

In order to achieve the above object, the stereophonic sound reproduction method of the present invention has an upper portion when the reproduction space is divided in the height direction in a reproduction space for reproducing a stereophonic signal composed of a plurality of channels. In the stereophonic sound reproduction method of reproducing the stereoacoustic signal with the upper layer, the middle part being the middle layer, and the lower part being the lower layer,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer A distribution step of distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. An output step of performing spatial sound field processing on the stereophonic sound signal so that a virtual sound source of each channel of the stereoacoustic signal can be heard from that direction when being reproduced by a group, and outputting it to the first and second speaker groups; The
It is characterized by having.

Further, in order to achieve the above object, the computer program of the present invention provides an upper layer when the reproduction space is divided in the height direction in a reproduction space for reproducing a stereophonic signal composed of a plurality of channels, In a computer program for causing a computer to reproduce the stereophonic signal having a middle part as a middle layer and a lower part as a lower layer,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer A distribution step of distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. An output step of performing spatial sound field processing on the stereophonic sound signal so that a virtual sound source of each channel of the stereoacoustic signal can be heard from that direction when being reproduced by a group, and outputting it to the first and second speaker groups; The
It is characterized by having.

  According to the present invention, it is possible to reproduce a sound field of a stereophonic signal in which a plurality of layers are configured by a plurality of channels and each of the plurality of layers is configured by a plurality of channels with a smaller number of speakers. . For example, when the stereophonic sound reproducing device of the present invention is used in a narrow space such as in a home, one or more small speakers are attached to the ceiling and further to the wall surface in order to reproduce the upper layer. It is possible to reproduce a sound field such as a 22.2 channel stereophonic sound signal without using a large speaker that interferes with daily life. In addition, even when the upper small speaker is installed in a place that does not interfere with daily life, the sound field of the 22.2 channel stereophonic sound signal can be reproduced.

Embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram showing a first embodiment of the stereophonic sound reproducing apparatus of the present invention. The sound reproducing apparatus of the present embodiment includes a reproduced sound field data acquiring unit 1, an acoustic input / output unit 2, a sound field analysis data calculating unit 3, a sound field dividing unit 4, and a head-related transfer function data for each direction. Means 5, impulse response creating means 6, audible means 7, and control means 8. As an example, a sound field of a 22.2 channel stereophonic sound signal is generated by 2n middle layer speakers and one upper layer speaker. Reproduce with 2n + 1 (<22) channels.

  The reproduction sound field data acquisition means 1 acquires specific data such as coordinates as reproduction sound field data as data relating to the room shape of the sound field for reproducing the acoustic signal and data of the sound receiving points. In short, the binaural impulse response from each speaker is necessary to cancel the crosstalk, so the binaural impulse response is calculated from the reproduction speaker data such as the spread angle data of the reproduction speaker, the listening position, the distance to the speaker, etc. Get the data to send. The sound input / output means 2 is an example of a stereophonic signal recorded externally as 22.2 channels (= middle layer 10 channels M1 to M10 + upper layer 9 channels U1 to U9 + lower layer 3 channels D1 to D3 + LFE2 channels LFE1, LFE2: FIG. The acoustic signal of FIG. 7) is input, and the acoustic signal of 2n + 1 channel (middle layer 2n channel + upper layer 1 channel: 2n + 1 <22) is output. The sound source of the middle layer 2n channel output by the sound input / output means 2 is a pair of two speakers in order to reproduce on the horizontal planes of the left and right ears, and the number of speakers is 2n (n is a positive integer). However, the number of speakers arranged on the ceiling (upper layer) is not necessarily so, and here, one speaker is used.

  The sound field analysis data calculation means 3 calculates the arrival direction, frequency characteristics, and arrival delay time of all sound rays from the 22.2 channel at the sound receiving point set in the sound field to be reproduced. The sound field dividing unit 4 calculates the number of divisions for dividing the sound field to be reproduced based on the number of speakers to be used, and divides the sound field into a plurality based on the number of divisions. At this time, among the 22.2 channels, the middle layer 10 channel + the lower layer 3 channel + the LFE2 channel 13.2 channels are distributed to 2n speakers arranged in the circumferential direction with the horizontal surface of the left and right ears as the middle layer. For the upper 9 channels, one or more channels including overhead channels are allocated to one or more upper speakers, and the remaining channels are allocated to 2n speakers in the middle layer. Here, since it is difficult to locate the sound image of the overhead channel using speakers that are not overhead, one ceiling (overhead) speaker must always be placed, which is effective for sensing the “special effect of sound coming from overhead” It is.

  The head-related transfer function data storage unit 5 by direction stores head-related transfer function data by direction of 22.2 channels in both ears of the human head. The direction-specific head-related transfer function will be described with reference to FIG. FIG. 2 is a conceptual diagram showing a base in the direction in which the head-related transfer function is measured. This is a head-related transfer function when a sound source is placed in the entire circumferential direction surrounding the human head 100. From these, the head-related transfer functions corresponding to the bases where the 22.2 channel speakers should be placed are collected and used as the head-related transfer functions by direction. In the case of the present embodiment, the celestial sphere 101 with a radius of 1 m centering on the human head 100 is considered, the elevation angle is set to 10 degrees vertically, the horizontal angle is set to every 5 degrees, and the impulse response is measured with both ears. Data is stored as a file. The data measured with both ears with the speakers at each site is one set for the left and right pairs. If each data is provided as sound to the left and right ears, it indicates that it can be heard in the measured direction.

  The impulse response creating means 6 is based on the data relating to all the sound rays calculated by the sound field analysis data calculating means 3 and the head transmission in the corresponding direction from among the head-related transfer function data storage means 5 by direction. Selects function data and performs data processing such as equalizing and delaying the arrival delay time. Furthermore, the corresponding speaker divided by the sound field dividing means 4 is specified from the data regarding all sound rays, and the head-related transfer function data processed for each specified speaker is distributed. Then, the head-related transfer function data distributed for each speaker is convolved with the input voice data to create an impulse response. A series of processes of the sound field analysis data calculation means 3, the direction-specific head related transfer function data storage means 5, and the impulse response creation means 6 described above are performed in the room where the 22.2 channel sound reproduction system is actually installed. Thus, it is the same as measuring and storing the head-related transfer function, sorting and adding each speaker. The audible means 7 convolves the transfer function calculated from the impulse response created for each speaker with the playback acoustic signal, and further performs a crosstalk cancellation process to create a playback acoustic signal for each speaker.

Next, the operation of the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the sound reproduction processing of the present invention. First, the reproduction sound field data acquisition means 1 acquires the data of the environment that is currently being auditioned, particularly the speaker and listening position (both ear positions) (step S1). Next, the position data of the recommended speaker to be reproduced in 22.2ch is calculated by the sound field analysis data calculation means 3 (step S2). At this time, the following three types of sound field analysis data (1) to (3) are calculated.
(1) Arrival direction of each sound ray of 22.2ch speaker arriving at sound receiving point, ie, horizontal angle and elevation angle data (2) Reflecting air absorption of each sound ray of 22.2ch speaker arriving at sound receiving point Frequency characteristic data (3) Arrival delay time data from the sound source of each sound line of the 22.2ch speaker arriving at the sound receiving point to the sound receiving point

  Next, in the sound field dividing means 4, the number 2n + 1 of speakers connected to the sound input / output means 2 is acquired via the control means 8 (step S3), and the number of speakers 2n other than the ceiling installation is even and four. If not (2n ≧ 4 (n is a positive integer)) (NO in step S4), an error occurs and the process ends. When the condition of 2n ≧ 4 is satisfied (YES in step S4), the horizontal plane at the ear height is divided into n areas A1 to An in the circumferential direction as the sound field to be reproduced (step S5). Two speakers are installed on the left and right in each of the areas A1 to An divided into n in the circumferential direction. The range of the divided areas A1 to An is calculated as follows.

  4 and 5 are explanatory views of an example of the installation positions of 2n + 1 speakers as viewed from directly above and from the side. In this example, one ceiling speaker C1 is installed in the upper layer, and four front left speakers L1, front right speaker R1, rear left speaker L2, and rear right speaker R2 are installed in the middle layer. In this embodiment, there are one speaker on the ceiling and four middle-layer speakers, so n = 2, and the sound field is divided into two. Here, when considering the entire spherical surface surrounding the listener, when the sphere centered on the listener is divided, it is divided into a front hemisphere area A1 and a rear hemisphere area A2 as shown in FIG. . For example, one of the 22.2ch recommended speaker positions corresponds to the front area A1 when the horizontal angle is 30 ° and the elevation angle is 0 °, and the other speaker position corresponds to the rear area A2 when the horizontal angle is 275 ° and the elevation angle is 40 °. . Thus, the corresponding area is determined by the number 2n and the positions of the speakers to be used.

  As shown in FIGS. 4 and 5, one ceiling speaker C1 is installed, and two front speakers (front speakers) L1 and R1 and two rear speakers (rear speakers) L2 and R2 are respectively connected to the front hemisphere area A1. The case where the 22.2 channel is assigned to each speaker C1, L1, R1, L2, R2 by installing in the rear hemisphere area A2 will be described with reference to FIG. First, for the upper nine channels U1 to U9, one overhead channel U1 is assigned to the ceiling speaker C1, and the remaining five channels U2 to U6 on the front side are assigned to the front speakers L1 and R1 in the front hemisphere area A1 and the rear three channels. U7 to U9 are distributed to the rear speakers L2 and R2 in the rear hemisphere area A2. For the middle 10 channels M1 to M10, the front 7 channels M1 to M7 are assigned to the front speakers L1 and R1, and the rear 3 channels M8 to M10 are assigned to the rear speakers L2 and R2. The lower three channels D1 to D3 are all assigned to the front speakers L1 and R1, and the LFE2 channels LFE1 and LFE2 are assigned to the front speakers L1 and R1, respectively. For the LFE2 channels LFE1 and LFE2, as shown in FIG. 7, the left channel LFE1 may be allocated to the left speakers L1 and L2, and the right channel LFE2 may be allocated to the right speakers R1 and R2.

  Returning to FIG. 3, the impulse response creating means 6 next performs impulses for each channel i (= 0, 1 to 21) based on the data regarding the sound receiving points and the speakers installed in the respective sound fields (step S <b> 6). A response is created. First, calculation processing of head-related transfer function data of 22.2 ch of sound rays is performed. From the horizontal angle and elevation angle data of the direct sound calculated by the sound field analysis data calculation means 3, corresponding left and right head transfer function data (1) is acquired from the head transfer function data storage means 5 by direction. (Step S7). Next, the acquired left-right paired head-related transfer function data is equalized for each band using the frequency data (2) calculated by the sound field analysis data calculation means 3 (step S8). This equalizing may be performed by any method, for example, FIR filter processing may be performed with 70 dB as a reference.

  Next, the equalized left and right pair of head related transfer function data is delayed by the delay time based on the arrival delay time data (3) of the sound calculated by the sound field analysis data calculation means 3 (step S9). . Next, the left-right paired head-related transfer function data and the input audio signal subjected to these processing processes are convoluted (step S10). These sounds are distributed to the corresponding areas of the divided sound field, and the left and right sounds are cumulatively added and distributed to the corresponding speakers (step S11). This processing is performed for each channel i (= 0, 1 to 21) (steps S12 and S13), and when the processing of all channels except the ceiling channel and 2ch LFE is completed (step S13 → YES), crosstalk cancellation is performed. Perform (step S14), and proceed to the audible processing (step S15).

  The audible means 7 creates sounds to be supplied to, for example, the ceiling speaker C1, the front speakers L1, R1, and the rear speakers L2, R2, and reproduces them on each speaker. The audio signal of the channel for the ceiling speaker C1 is given with a delay corresponding to the processing time from step S6 to step S13 in order to synchronize with the acoustic signals reproduced from the front speakers L1, R1 and the rear speakers L2, R2. The audible audio signal for reproduction is output from the sound input / output means 2 via the control means 8. The two-channel effect signal (LFE) is also supplied to the front speakers L1, R1 and the rear speakers L2, R2 with a delay corresponding to the processing time up to step S13.

6 and 7 are block diagrams showing the above processing. The head-related transfer functions according to directions of all the channels U2 to U9, M1 to M10, and D1 to D3 other than the ceiling channels U1 and LFE2 channels LFE1 and LFE2 are:
U: (U2L1, U2R1) to (U5L1, U5R1), (U6L2, U6R2) to (U8L2, U8R2), (U9L1, U9R1)
M: (M1L1, M1R1) to (M7L1, M7R1), (M8L2, M8R2) to (M10L2, M10R2),
D (D1L1, D1R1) to (D3L1, D3R1)
The channels U2 to U9, M1 to M10, and D1 to D3 are convolved.

  Next, the upper five channels U2 to U6 are assigned to the front speakers L1 and R1, the remaining three channels U7 to U9 are assigned to the rear speakers L2 and R2 in the rear hemisphere area A2, and the middle layer seven channels M1 to M7 are assigned to the front speakers L1. , R1 and the remaining three channels M8 to M10 are assigned to the rear speakers L2 and R2, and the lower three channels D1 to D3 are all assigned only to the front speakers L1 and R1 (adders 11L, 11R, 12L and 12R). Next, forward and rearward crosstalk cancellation is performed in the first and second crosstalk cancellation circuits 21 and 22, respectively, based on the reproduction sound field data information calculated in step S1.

  In the configuration shown in FIG. 6, the ceiling channel U1 is delayed by the delay circuit 13 and supplied to the ceiling speaker C1. The LFE channels LFE1 and LFE2 are delayed by the delay circuits 14 and 15, respectively, and supplied to the front speakers L1 and R1 via the adders 23L1 and 23R1. In the configuration shown in FIG. 7, the left LFE channel LFE1 is delayed by the delay circuits 14L1 and 14L2, supplied to the left speakers L1 and L2 via the adders 23L1 and 23L2, and the right LFE channel LFE2 is the delay circuit. The signals are delayed by 15R1 and 15R2 and supplied to the right speakers R1 and R2 via the adders 23R1 and 23R2.

  The crosstalk cancellation process (step S14) of the present embodiment will be described with reference to FIG. Here, the crosstalk cancellation process is performed only on the signals distributed to the speakers L1, R1, L2, and R2. First, let s1 (t) be an acoustic signal input to the speaker SP1 in the area A1, and h1l (t) and h1r (t), which are transfer functions of the left and right pairs of the speaker SP1, are convolved with this s1 (t). Signals VL1 (t) and VR1 (t) to be reproduced in the left and right ears of the listener are obtained. These VL1 (t) and VR1 (t) are expressed by the following formula (1).

  The obtained VL1 (t) and VR1 (t) are signals subjected to sound image localization processing by convolution of the transfer function, and reproduce VL1 (t) in the left ear and VR1 (t) in the right ear. Thus, the listener sounds as if it is ringing from the speaker SP1. When these signals are reproduced by the front speakers L1 and R1, a crosstalk canceling process is performed so that the listener can hear them as if they are sounding from the speaker SP1. Here, h1ll (t) is a transfer function for reproducing the sound from the front left speaker L1 to the left ear of the listener in the sound field to be reproduced, and h1lr (t) is a transfer function for reproducing to the right ear. A transfer function for reproducing the sound from the front right speaker R1 to the listener's left ear is h1rl (t), and a transfer function for reproducing the sound to the right ear is h1rr (t). Thereby, signals L1 (t) and R1 (t) to be transmitted to the front speakers L1 and R1 are expressed by the following equation (2).

The above shows the sound arriving at the area A1 from one speaker SP1. When m is the number of sounds covering the area A1, all audio signals VL1 _ALL (t) and VR1 _ALL (t) in the area A1 are expressed by the following equation (3).

Therefore, assuming that the signals to be transmitted to the left and right speakers L1 and R1 in the area A1 are L1 _ALL (t) and R1 _ALL (t), these are expressed by the following equation (4).

  The same relationship is obtained for the area A2, and the signal VL2 (t) obtained by convolving the acoustic signal s2 (t) and the transfer function h2l (t) input to the speaker SP2 is s2 (t ) And the transfer function h2r (t) are reproduced to the right ear by reproducing the signal VR2 (t) obtained by convolution with the transfer function h2r (t).

  Therefore, the transfer function for reproducing the signal from the rear speaker L2 in the area A2 to the listener's left ear is h2ll (t), the transfer function for reproducing the signal to the right ear is h2lr (t), and the rear right speaker R2 Is to be transmitted to the rear speakers L2 and R2, respectively, by using h2rl (t) as a transfer function for reproducing the signal in the left ear of the listener and h2rr (t) as a transfer function for reproducing to the right ear. The signals L2 (t) and R2 (t) are expressed by the following equation (2) ′.

Similarly, if the signals to be transmitted to the left and right speakers L2 and R2 in the area A2 are L2 _ALL (t) and R2 _ALL (t), respectively, these are expressed by the following equation (4) ′.

From the above, the signals Ln _ALL (t) and Rn _ALL (t) to be transmitted to the left and right speakers Ln and Rn in the area An are expressed by the following equation (5).

  By performing these crosstalk cancellation processes, the audible acoustic signals are transmitted to the corresponding speakers, and the total reflected sound including the direct sound output from the speakers is reproduced so that it can be heard from the appropriate direction of arrival. The

  In addition, as shown in FIG. 7, the LFE channel is also supplied to the rear speaker, so that the sense of reality can be further improved. In this case, by enabling the listener to make adjustments, or by providing an automatic adjustment gain variable device and delay device, a low-frequency enveloping is realized, and a more natural and powerful sound field can be reproduced. The ceiling speaker to which the upper layer channel signal is supplied may be fixed as well as movable. Further, the height of the ceiling speaker to which the upper layer channel signal is supplied may be adjustable, and in this case, the volume of the channel signal can also be adjusted by a volume or the like (not shown).

  As described above, at least one speaker can be set on the ceiling, and the upper sound image localization that has been insufficient up to now can be accurately performed. In addition, an audible sound signal is created from the reproduction sound signal based on the head-related transfer function data for each direction, and the audible sound signal is further divided into a plurality of areas, and two or more pairs of pairs are formed. Since it is also reproduced from behind using a speaker, sound image localization in the backward direction can be performed more accurately, and a high-quality reproduced sound field with a more realistic feeling can be realized. Here, when the positions and the number of speakers to be arranged are determined, the coefficients of the crosstalk cancellation circuit and the delay circuit may be calculated and supplied in advance by the above-described steps S1 to S13, etc. Needless to say, it is not necessary to calculate the coefficients of the crosstalk cancellation circuit and the delay circuit every time the circuit is started up.

<Second Embodiment>
In the first embodiment, even if there is only one speaker to be placed on the ceiling, the sound of one channel from above physically comes in, so that a feeling of being wrapped from above is obtained, and the middle layer However, there is still room for improvement in accurately reproducing the sense of distance (depth) of each of the upper 9 channels U1 to U9. Therefore, in the second embodiment, two upper speakers (hereinafter referred to as “upper speakers”) are used for the purpose of reproducing the arrival directions of a plurality of upper channels and making it easy to recognize the distance of each channel. , UL1, and UR2). According to the second embodiment, if two speakers are added above the front wall instead of the ceiling, there is no resistance in installation and the user can easily arrange them. Here, FIG. 9 shows the speaker arrangement of upper layer channels U1 to U9 among p20 of Non-Patent Document 1 and 22.2 channels disclosed in Table 1. The channel U1 is located almost overhead, and the other channels U2 to U9 are arranged in a range of 360 ° from the front left side in the clockwise direction at substantially the same height as the channel U1.

  The configuration of the second embodiment is shown in FIG. Since the configuration other than the sound input / output means 22 is almost the same as that shown in FIG. 1, the same components as those shown in FIG. In the present embodiment, since there are two upper-layer speakers, the number of output channels of the sound input / output means 22 is 2n + 2 channels. The operation of the second embodiment will be described with reference to FIGS. FIG. 11 is a flowchart showing the flow of a rough sound reproduction process of the present invention, FIG. 12 is a flowchart for explaining the “sound field dividing process” in FIG. 11 in detail, and FIGS. 13 to 15 are explanatory diagrams showing examples of upper layer division, FIG. 16 is an explanatory diagram showing an example of “upper spatial sound field processing” in FIG. 11, FIG. 17 is a flowchart for explaining in detail “upper spatial sound field processing” in FIG. 11, and FIG. 18 is a second embodiment. It is a block diagram which shows the example of distribution of the stereophonic signal in the stereophonic sound reproduction apparatus of 1, and the example of a spatial sound field process.

  Step S21 and step S22 shown in FIG. 11 are the same as step S1 and step S2 shown in FIG. In step S21, the reproduction sound field data acquisition unit 1 acquires the speaker and listening position data. In step S22, the sound field analysis data calculation unit 3 performs the sound field analysis data (1) to (3) described above. (1) to (3) are calculated.

  Next, as shown in detail in FIG. 12, the sound field dividing means 4 divides the sound field to be handled by each speaker from the number of speakers connected to the output side of the sound input / output means 22 (step S23). . First, the spatial sound field processing in the upper layer is performed (step S24). Here, the divided areas and processing of the sound field corresponding to the arrangement pattern of the two speakers UL1 and UR1 arranged in the upper layer with respect to the upper layer channels U1 to U9 are performed. In particular, the two speakers UL1 and UR1 are the listeners. If the relation is an isosceles triangle with the listener as the apex, biased forward or backward, spatial sound field processing is performed using the direction-specific head-related transfer function data storage means 5 and the impulse response creation means 6. Next, for the middle layer channels M1 to M10 and the lower layers D1 to D3, the space to be supplied to 2n speakers arranged in the middle layer using the head-related transfer function data storage unit 5 and the impulse response creating unit 6 in the same direction. Sound field processing is performed (step S25). Finally, the audible means 7 performs crosstalk cancellation for each pair of speakers (step S26), and a signal is reproduced via an amplifier (not shown) (step 27).

  The sound field dividing process in step S23 will be described in detail with reference to the flowchart of FIG. The number 2n of speakers connected to the output side of the sound input / output unit 22, the number of upper layer speakers = 2, and the arrangement pattern of the upper layer speakers are acquired by the input unit (not shown) via the control unit 8 (step S31). ) If the number of speakers 2n + 2 is not an even number and 4 or more (n is a positive integer) (NO in step S32), an error occurs and the process ends. When the condition of 2n + 2 ≧ 4 is satisfied (YES in step S32), the horizontal plane at the ear height is divided into n areas A1 to An in the circumferential direction as the sound field to be reproduced (step S33). Two speakers are installed on the left and right in each of the areas A1 to An divided into n in the circumferential direction. The range of the divided areas A1 to An is calculated by (Equation 1) described above.

  Next, when the speaker arrangement pattern arranged in the upper layer is placed before and after the listener as shown in FIG. 13B (YES in step S34), the sound field before the listener is The sound field is divided into two parts (step S35), and then the process ends. On the other hand, if the arrangement pattern is not before or after the listener (NO in step S34) but placed on the left and right sides as shown in FIG. 14B (YES in step S36), the listening The sound field on the left side and the sound field on the right side are divided into two (step S37), and the process is then terminated. The arrangement pattern is not right or left across the listener (NO in step S36), but is an isosceles triangle that is biased to the front (or rear) of the listener as shown in FIG. If it is installed in a shape (YES in step S38), it is not divided (step S39), and then the process ends. If none of the three arrangement patterns is present (NO in step S38), an error occurs and the process ends.

  13, 14, and 15 are examples of sound field division in the case where the middle-layer speakers at the height of the ears are 4 and the arrangement of the upper-layer speakers UL1 and UR2 is three patterns. FIG. FIGS. 13 (a), 14 (a), and 15 (a) show divided regions other than the upper layer, each of which is composed of front two channels L1 and R1 and rear two channels L2 and R2. Since there are four speakers in this layer, n = 2 and the sound field is divided into two. Here, when considering the entire spherical surface that surrounds the listener, the area is divided on a horizontal circle centered on the listener, and when the sphere is divided, the elevation angle is 0 degree and FIGS. a) As shown in FIG. 15A, it is divided into a front area A1 and a rear area A2. For example, in the recommended speaker position of 22.2 ch, all channels other than the upper layer are allocated to the area A1 or A2. For example, when the horizontal angle is 30 ° and the elevation angle is 0 °, it corresponds to the area A1, and when another speaker position is the horizontal angle 275 ° and the elevation angle is 40 °, it corresponds to the area A2. Thus, the corresponding area is determined by the speaker position.

  FIG. 13B, FIG. 14B, and FIG. 15B show the upper divided areas. For the upper layer 9 channels U1 to U9 of the recommended speaker position where the elevation angle is 45 degrees or more, when speakers are installed before and after the listener as shown in FIG. 13B (UF, UR in the figure), the horizontal plane Is divided into a front area B1 and a rear area B2. In addition, when the upper speakers are installed on the left and right sides of the listener as shown in FIG. 14B (UL, UR in the figure), for the upper 9 channels of the recommended speaker position where the elevation angle is 45 degrees or more, The listener is divided into a left area C1 and a right area C2. As shown in FIG. 15 (b), when the upper speaker is biased forward (or backward) of the listener and installed in a triangular shape with the listener at the apex (UFL, UFR in the figure), the elevation angle The upper layer 9 channels U1 to U9 of the recommended speaker position where the angle is 45 degrees or more is not divided (area D).

  Next, the “upper spatial sound field processing” in step S24 shown in FIG. 11 will be described in detail with reference to FIG. Here, sound field processing is performed according to the upper layer speaker arrangement pattern as shown in FIGS. 13B, 14B, and 15B, but FIG. 16 is an example of FIG. 14B. The case where upper-layer speakers are installed on the left and right as shown in FIG. First, when the sound field dividing means 4 divides the upper layer back and forth as shown in FIG. 13B, among the upper layer input channels U1 to U9, the channels U2 to U5 included in the listener's front area B1. , U9 (see FIG. 9) are added, the signals of channels U6 to U8 included in the rear area B2 are added, and the overhead channel U1 at the boundary between the areas B1 and B2 is ½ And the multiplication result is added to the signals in areas B1 and B2.

  Further, when the sound field dividing means 4 divides the upper layer into two left and right as shown in FIG. 14B, among the upper input channels U1 to U9 as shown in FIG. The signals of channels U2, U8, and U9 included are added, and the signals of channels U4, U5, and U6 included in the right area C2 are added. Further, the signals of channels U1, U3, and U7 that are the boundaries of areas C1 and C2 are added, the addition result is multiplied by 1/2, and the multiplication result is added to the signals of areas C1 and C2.

  Next, the spatial sound field process when the sound field dividing means 4 is “not divided for the upper layer” (step S39 in FIG. 12) will be described. For example, as shown in FIG. 15 (b), from the left and right speakers placed in a triangular shape with the listener at the top and biased to the front (or rear) of the listener, All the channels U1 to U9 in the upper layer shown in FIG. 9 are subjected to sound image localization processing and reproduced.

  FIG. 17 is a flowchart showing in detail the “upper spatial sound field processing” in step S24 shown in FIG. In the present embodiment, the impulse response creating means 6 first performs a calculation process of head-related transfer function data of sound lines for 9 ch. The calculation method is the same as in the first embodiment. The impulse response creating means 6 sets the upper layer channel i to the initial value 0 based on the data regarding the sound receiving point and the speakers installed in the respective sound fields in step S41. Then, steps S42 to S48 are repeated until i is determined to be 9 or more in step S48, and an impulse response is created for each channel i. Subsequent steps S42 and S43 are the same as steps S7 and S8 in the first embodiment, and thus will not be described in particular.

  Since step S44 and step S45 are the same as step S9 and step S10 of the first embodiment, they are not specifically described. In step S46, the left and right sounds are cumulatively added and distributed to the corresponding upper speakers (step S46). If this process is repeated for all channels in the upper layer (step S48 → YES), if all channels are completed (step S48 → NO), the process proceeds to “spatial sound field processing other than upper layer” in step S25 of FIG.

  In “spatial sound field processing other than upper layer” in step S25 of FIG. 11, left and right impulse responses for 13.2 ch excluding upper 9 ch out of 22.2 ch are created and convolved with the corresponding input audio signal. Then, the left and right sounds are cumulatively added for each of the corresponding speakers L1, R1, L2, and R2, and distributed to the front speakers L1 and R1 and the rear speakers L2 and R2. When “upper spatial sound field processing” and “spatial sound field processing other than upper layer” are completed, the process proceeds to crosstalk cancellation (step 26) and signal reproduction (step 27).

  The audible means 7 creates sounds to be supplied to the above two upper speakers UL1, UR1, the front speakers L1, R1, and the rear speakers L2, R2, and each speaker UL1, UR1, L1, R1, L2, Play with R2. Since the sound signals reproduced from the respective speakers UL1, UR1, L1, R1, L2, and R2 need to be synchronized, they are given with a delay corresponding to the processing time from step S24 to step S25. The audible audio signal for reproduction is output from the sound input / output means 2 via the control means 8. Note that the 2-channel effect signal (LFE) does not need to be processed in the spatial sound field when the subwoofer is specially processed, and only the delay processing for the processing time up to step S26 is performed to the subwoofer. What is necessary is just to supply.

FIG. 18 is a block diagram for realizing the above processing. Directional head related transfer functions of all channels U1-U9, M1-M10, D1-D3, LFE1, LFE2 are:
U: (U1UL1, U1UR1) to (U9UL1, U9UR1)
M: (M1L1, M1R1) to (M7L1, M7R1) ... (M8L2, M8R2) to (M10L2, M10R2)
D: (D1L1, D1R1) to (D3L1, D3R1)
LFE: (LFE1L1, LFE1R1), (LFE2L1, LFE2R1)
The channels U1 to U9, M1 to M10, D1 to D3, and LFE1 to LFE2 are convolved.

  Next, according to the speaker arrangement shown in FIG. 13 (b), FIG. 14 (b) or FIG. 15 (b), the upper 9 channels U1 to U9 are distributed to the upper speakers UL1 and UR1 (adders 11L and 11R). . Further, the middle seven front channels M1 to M7, the lower three channels D1 to D3, LFE1 and LFE2 (all of which are front channels) are all distributed to the front speakers L1 and R1 (adders 12L and 12R). Further, the remaining rear three channels M8 to M10 in the middle layer are distributed to the rear speakers L2 and R2 (adders 13L and 13R). Here, the adders 11L, 11R, 12L, 12R, 13L, and 13R shown in FIG. 18 are merely shown for explanation. In practice, for example, as shown in FIG. Includes a coefficient multiplier.

  Next, on the basis of the calculated reproduction sound field data information, the first, second, and third crosstalk cancel circuits 21, 22, and 23 perform the upper layer, front, and rear crosstalk cancellation (step S26), respectively. Here, the crosstalk cancellation processing for the middle layer has been described with reference to FIG. 8, but for the upper layer, L1 and R1 in FIG. 8 are the upper layer speakers UL1 and UR1, and the upper layer speakers SP1 and SP2 are reproduced. , It can be seen that the formula can be established with the same relationship. By performing these crosstalk cancellation processes, the audible acoustic signals are transmitted to the corresponding speakers, and the sound output from the 2n + 2ch speakers is reproduced so that it can be heard from the appropriate direction of arrival of 22.2ch. Is done.

  As described above, by providing the two speakers UL1 and UR1 on the ceiling and performing the optimal sound field reproduction processing according to the arrangement pattern, the upper sound image localization that has been difficult to reproduce until now only in the direction of arrival has been difficult. Can be done accurately. Also, an audible sound signal is created from the reproduction sound signal based on the head-related transfer function data for each direction, and the audible sound signal is further divided into a plurality of areas, and one or more pairs of speakers. Can be reproduced from behind, so that the sound image localization in the backward direction can be performed more accurately, and a more realistic sound field with a higher sound quality can be realized. Here, when the speaker positions and the number of speakers to be arranged are determined, the coefficients of the crosstalk cancellation circuit and the delay circuit may be calculated and supplied in advance through steps S21 to S25 described above, It goes without saying that it is not necessary to calculate the coefficients of the crosstalk cancellation circuit and the delay circuit every time the apparatus is started up.

  Although the LFE channels LFE1 and LFE2 perform sound image localization in this embodiment, when there are two subwoofers, two delay circuits are provided with the time required for spatial sound field processing other than the upper layer and the upper layer as a delay amount. May be supplied to two subwoofers, or if there is no subwoofer, addition processing may be performed after the second crosstalk cancellation circuit 22 and supplied to the front speakers L1 and R1.

<Third Embodiment>
When there are two speakers to be placed on the ceiling, there is still room for improvement in accurately reproducing the sense of direction from the rear in addition to the sense of distance (depth) of each of the upper 9 channels U1 to U9. . Therefore, in the third embodiment, in addition to the sense of distance (depth) of each of the upper layer 9 channels U1 to U9, in order to accurately reproduce the sense of direction from the rear, the upper layer speakers are connected to the front left and right 2 It is assumed that the number (UL1, UR1) + the left and right two (UL2, UR2). According to the third embodiment, it seems that the user also adds speakers before and behind the wall instead of the ceiling, or stacks another speaker above the conventional horizontal level speaker. If a vertically long speaker is installed, there is no resistance in installation, and it can be easily arranged.

  The configuration of the third embodiment is almost the same as the configuration shown in FIGS. 1 and 10 as shown in FIG. 19, but the number of output channels of the sound input / output means 202 is 2 + 2, because there are 2 + 2 upper speakers. Are 2n + 4 channels. Since the flow of the rough sound reproduction process of the third embodiment is the same as that in FIG. 11, detailed description thereof is omitted.

FIG. 20 shows in detail the sound field dividing process in the upper layer in step 23 of FIG. The number of middle layer speakers connected to the sound input / output unit 2 = 2n and the number of upper layer speakers = 2 + 2, and the arrangement pattern of the upper layer speakers are acquired by the input unit (not shown) via the control unit 8 (step S31). If the number of speakers 2n + 4 is not an even number and 6 or more (n is a positive integer) (NO in step S32), an error occurs and the process ends. When the condition of 2n + 4 ≧ 6 is satisfied (YES in step S32), first, the sound field to be reproduced is divided into n areas A1 to An in the circumferential direction on the horizontal plane (step S33). Two speakers are installed on the left and right in each of the areas A1 to An divided into n in the circumferential direction. The range of the divided areas A1 to An is calculated by (Equation 1) as in the first and second embodiments. Next, the upper layer of the sound field, that is, the portion having an elevation angle of 45 degrees or more in FIG. 2 is divided into two front and rear areas B1 and B2 as shown in FIG. 21B (step S34). As for the upper layer, a total of 2 + 2 speakers are installed on the left and right in the divided areas B1 and B2.

  FIG. 21A is an explanatory view of an example of the installation positions of 2n + 4 speakers viewed from directly above, and FIG. 21B is an explanatory view of FIG. Is forward. Regarding the sound field division area, the front area A1 and the rear area A2 other than the upper layer, and the front area B1 and the rear area B2 of the upper layer with an elevation angle of 45 degrees as a boundary are shown. In this example, the upper layer front speakers UL1 and UR1 are arranged in the area B1, and the upper layer rear speakers UL2 and UR2 are arranged in the area B2. Further, the front speakers L1, R1 and the rear speakers L2, R2 are installed in the front area A1 and the rear area A2, respectively.

  That is, in the third embodiment, as in the second embodiment, since there are four middle-layer speakers, n = 2, and the sound field other than the upper layer is divided into two areas A1 and A2. On the other hand, for the upper 9 channels U1 to U9 of the recommended speaker position with an elevation angle of 45 degrees or more, as shown in detail in FIG. 21B, the upper front area B1 and the rear area for the sound field with an elevation angle of 45 degrees or more. Divided into B2.

  “Spatial sound field processing in the upper layer” follows the flowchart shown in FIG. The third embodiment is different from the second embodiment in steps S46 to S48. Steps S41 to S45 are substantially the same as those in the second embodiment, and thus will not be particularly described.

  In the third embodiment, the left and right sounds are cumulatively added for each of the sound fields B1, B2 (four divided areas) divided in step S46, and the corresponding upper front speakers UL1, UR1, upper rear speaker UL2 are added. , UR2 (step S46). This process is repeated for all channels in the upper layer (step S48 → YES). When all channels are completed (step S48 → NO), the process proceeds to “spatial sound field processing other than upper layer” (step S25). Since the processing after step S25 is the same as that of the second embodiment, a description thereof will be omitted.

  FIG. 22 is a block diagram for realizing the above processing. For the upper nine channels U1 to U9, the channels U2 to U5 and U9 are allocated to the upper front speakers UL1 and UR1, and the channels U1 and U6 to U8 are allocated to the upper rear speakers UL2 and UR2 (adders 31L and 31R). , 32L, 32R). Similarly to the second embodiment, the middle 7 front channels M1 to M7 and the lower 3 channels D1 to D3 and LFE1 and LFE2 (all of which are front channels) are all distributed to the front speakers L1 and R1 (addition). 33L, 33R). Further, the remaining rear three channels M8 to M10 in the middle layer are distributed to the rear speakers L2 and R2 (adders 34L and 34R). Here, the adders 31L to 34L and 31R to 34R shown in FIG. 22 are merely shown for explanation, and actually, as shown in FIG. 16, for example, more adders and coefficient multipliers are provided. Including.

The upper layer areas B1 and B2 may be further divided into left and right parts (total of 4 parts). Here, the overhead channel U1 is assigned to the rear side. Among the upper layer channels U1 to U9, the left channel U2 and U9 are added in front of the listener and distributed to the upper layer front left speaker UL1, and the right channel U4 and U5 are added in front to the upper layer front right speaker UR1. Distribute. Further, ½ of the channel U3 at the front center of the upper layer is distributed to the speakers UL1 and UR1. The left channel U8 is assigned to the upper rear left speaker UL2 behind the listener, and the right channel U6 is assigned to the upper rear right speaker UR2 behind. Further, the channels U1 and U7 on the upper rear side are added, and ½ of the addition result is distributed to the speakers UL2 and UR2.

  Next, on the basis of the reproduced sound field data information calculated in step S21, the first to fourth crosstalk cancel circuits 41 to 44 perform upper front and rear, front and rear crosstalk cancellation, respectively. As for the crosstalk cancellation in the upper areas B1 and B2, L1 and R1 in FIG. 8 reproduce the upper speaker SP1 with the upper front speakers UL1 and UR1, and L2 and R2 in FIG. 8 correspond to the upper rear speakers UL2 and UR2. Considering that the upper speaker SP2 is reproduced, it can be seen that the equation can be established with the same relationship. By performing these crosstalk cancellation processes, audible acoustic signals are transmitted to the corresponding speakers, and reproduced so that the sound output from the 22.2 ch speakers can be heard from the appropriate direction of arrival.

  As described above, by providing the upper front and rear speakers UL1, UR1, UL2, UR2, it is possible to accurately perform the upper front and rear sound image localization which has been insufficient until now. In addition, an audible sound signal is created from the reproduction sound signal based on the head-related transfer function data for each direction, and the audible sound signal is divided into a plurality of areas to be divided into four or more pairs of speakers. Since it is also reproduced from behind, a high-quality reproduced sound field with a more realistic feeling can be provided. Here, the head-related transfer functions LFE1L1, LFE1R1, LFE2L1, and LFE2R1 for LFE1 and LFE2 by direction may be replaced with simple delay functions. Furthermore, it goes without saying that the present invention can be applied to other stereophonic systems such as the intermediate layer 10 channel + upper layer 9 channel + LFE 2 channel 19.2 channel system (the system in which the lower layer of the 22.2 channel system is omitted) and the like. Absent.

  Here, when the positions and the number of speakers to be arranged are determined, the coefficients of the crosstalk cancellation circuit and the delay circuit may be calculated and supplied in advance by the above-described steps S21 to S25, etc. Needless to say, it is not necessary to calculate the coefficients of the crosstalk cancellation circuit and the delay circuit every time the circuit is started up.

  In addition, this invention contains the program for making a computer implement | achieve the function of said sound reproduction apparatus. This program may be read from a recording medium and loaded into a computer, or may be transmitted via a communication network and loaded into a computer. In particular, the speaker disposed on the ceiling is preferably a speaker that is wireless and can also supply power wirelessly.

It is a block diagram which shows the stereophonic sound reproduction apparatus by the 1st Embodiment of this invention. It is a conceptual diagram which shows the direction used for the head-related transfer function according to direction in the stereophonic sound reproduction apparatus of FIG. It is a flowchart which shows the process of the stereophonic sound reproduction apparatus of FIG. It is a top view which shows the installation position of the speaker in the stereophonic sound reproduction apparatus of FIG. It is a side view which shows the installation position of the speaker in the stereophonic sound reproduction apparatus of FIG. It is a block diagram which shows the example of distribution of the stereophonic signal in the stereophonic sound reproduction apparatus of FIG. 1, and the example of a spatial sound field process. It is a block diagram which shows the other example of distribution of the stereophonic sound signal in the stereophonic sound reproduction apparatus of FIG. 1, and the example of a spatial sound field process. It is explanatory drawing which shows the transfer function of the horizontal direction from the installation position of each speaker in the stereophonic sound reproduction apparatus of FIG. 1, and each speaker to a listener's both ears. It is explanatory drawing which shows the speaker arrangement | positioning of upper layer channel U1-U9 among 22.2 channels. It is a block diagram which shows the stereophonic sound reproduction apparatus by the 2nd Embodiment of this invention. It is a flowchart which shows the process of the stereophonic sound reproduction apparatus of FIG. 12 is a flowchart for explaining in detail an upper-layer sound field dividing process in the “sound field dividing process” of FIG. 11. It is explanatory drawing which shows the example of a division | segmentation of an upper layer. It is explanatory drawing which shows the example of a division | segmentation of an upper layer. It is explanatory drawing which shows the example of a division | segmentation of an upper layer. It is explanatory drawing which shows an example of upper layer channel distribution in FIG. 12 is a flowchart for explaining in detail “upper spatial sound field processing” in FIG. 11. It is a block diagram which shows the example of distribution of the stereophonic sound signal in the stereophonic sound reproduction apparatus of 2nd Embodiment, and the example of a spatial sound field process. It is a block diagram which shows the stereophonic sound reproduction apparatus by the 3rd Embodiment of this invention. It is a flowchart explaining in detail the upper layer sound field division | segmentation process in the 3rd Embodiment of this invention. It is explanatory drawing which shows the upper layer sound field division | segmentation example in the 3rd Embodiment of this invention. It is a block diagram which shows the example of distribution of the stereophonic sound signal in the stereophonic sound reproduction apparatus of 3rd Embodiment, and the example of a spatial sound field process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reproduction | regeneration sound field data acquisition means 2,22,202 Sound input / output means 3 Sound field analysis data calculation means 4 Sound field division means 5 Head transfer function data storage part according to direction 6 Impulse response creation means 7 Audible means 8 Control means

Claims (3)

In a reproduction space for reproducing a stereophonic signal composed of a plurality of channels, the stereoacoustic signal is reproduced with the upper part being the upper layer, the middle part being the middle layer, and the lower part being the lower layer when the reproduction space is divided in the height direction. In a three-dimensional sound reproduction device,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer Means for distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. A spatial sound field that is processed by a spatial sound field so that a virtual sound source of each channel of the stereophonic signal can be heard from that direction and is output to the first and second speaker groups when reproduced by a group. Processing means,
A stereophonic sound reproducing apparatus comprising: In a reproduction space for reproducing a stereophonic signal composed of a plurality of channels, the stereoacoustic signal is reproduced with the upper part being the upper layer, the middle part being the middle layer, and the lower part being the lower layer when the reproduction space is divided in the height direction. In the three-dimensional sound reproduction method,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer A distribution step of distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. An output step of performing spatial sound field processing on the stereophonic sound signal so that a virtual sound source of each channel of the stereoacoustic signal can be heard from that direction when being reproduced by a group, and outputting it to the first and second speaker groups; The
A stereophonic sound reproducing method comprising: In a reproduction space for reproducing a stereophonic signal composed of a plurality of channels, when the reproduction space is divided in the height direction, the stereoacoustic signal with the upper part being the upper layer, the middle part being the middle layer, and the lower part being the lower layer is provided to the computer. In a computer program to be played,
The first channel group including at least one channel among the plurality of channels reproduced in the upper layer, the plurality of channels excluding the first channel group reproduced in the upper layer, and the middle layer A distribution step of distributing to a second channel group including a plurality of channels to be reproduced and a plurality of channels to be reproduced in the lower layer;
The first speaker group is reproduced by a first speaker group including one or more speakers disposed in the upper layer, and the second channel group includes a plurality of speakers disposed in the middle layer. An output step of performing spatial sound field processing on the stereophonic sound signal so that a virtual sound source of each channel of the stereoacoustic signal can be heard from that direction when being reproduced by a group, and outputting it to the first and second speaker groups; The
A computer program comprising:

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