JP2897643B2 - Sound field control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound field control device for providing a sound field effect in music reproduction, and to create a sound field having a three-dimensional feeling and a spacious feeling with at least two speakers. It was done.

[0002]

2. Description of the Related Art Recent music reproduction is required to provide a so-called sound field effect as a more advanced function.
The sound field effect is an effect that can give a sense of realism as if the user is in another space such as an actual hall while staying in a small room. In the conventional sound field effect, at least four or more sub-speakers are arranged so as to surround a room in which a sound field is to be reproduced, and a reflected sound signal generated for each direction based on a source signal is output from each sub-speaker. It was realized by playing.

FIG. 2 shows a conventional system configuration for providing a sound field effect in music reproduction. Left and right two-channel source signals L and R transmitted from the source device 10 are input to the sound field control device 16 via the input terminals 12 and 14. Here, the sound field control device 16 is configured as a stereo pre-main amplifier having a sound field effect imparting function, and converts an input source signal into a preamplifier 18 and a power amplifier 2.
0 and 22 to the speaker output terminals 24 and 26.

[0004] The source signals L and R are input to reflected sound signal generation means 28 (sound field effect processor). The reflected sound signal generating means 28 includes at least four or more loudspeakers arranged around a listening point in the room based on the reflected sound data obtained corresponding to each virtual sound source position of the reflected sound in an acoustic space such as a hall. In order to reproduce a large number of reflected sounds in the acoustic space or a model space similar thereto using impulse response characteristics, an impulse response characteristic of a reflected sound group to be emitted by each speaker is stored as a reflected sound parameter, and these stored. By performing a convolution operation on a common source signal with respect to each reflected sound parameter, a signal (reflected sound signal) of a large number of reflected sound groups to be emitted from each speaker is generated, and the corresponding position of each of the speakers is determined. It is originally configured to provide a sound field effect by supplying it to each of the objects. , JP-A-61-257099, see JP-A-62-53100, etc.). That is, the source signals L and R input to the reflected sound generation circuit 28 are
Are combined into one channel of LR or L + R. 1
The source signal combined with the channel is passed through a low-pass filter 32 for preventing aliasing at the time of A / D conversion.
The digital signal is converted by the D converter 34. Further, in order to give a frequency characteristic to the reflected sound, the digital signal is branched into digital filters 36, 38, 40, and 4.
Passed through 2. Digital filters 36, 38, 40,
The source signal output from 42 is input to reflected sound generation circuits 44, 46, 48, and 50 of each channel.

[0005] In the ROM 52, various acoustic spaces (halls, halls, etc.) composed of delay time data and gain data as shown in FIG.
A reflected sound parameter for each direction in a studio, jazz club, church, karaoke room, etc.) is stored. The reflected sound generation circuits 44, 46, 48, 50
Based on the reflected sound parameter of one mode arbitrarily selected from the reflected sound parameters stored in the OM 52,
By performing a convolution operation with the source signal, a reflected sound signal of the source signal is generated for each channel. These generated reflected sound signals are D / A converted by the D / A converter 54 in a time division multiplex manner. D / A converter 5
The output signal of No. 4 is distributed to each channel, smoothed by low-pass filters 56, 58, 60 and 62, returned to analog signals, and output from the reflected sound signal generating means 28. FL (front left), FR (front right), RL (rear left), R output from the reflected sound signal generation means 28
The reflected sound signals of the R (rear right) channels are guided to speaker output terminals 72, 74, 76, 78 via power amplifiers 64, 66, 68, 70, respectively.

The left and right two-channel main signals L and R output from the sound field control device 16 are
Main speaker 84 arranged in front of the listening point 82 of the
86 respectively. Further, the reflected sound signals FL, FR, RL, and RR of the four channels are output to the listening room 8.
Sub-speakers 88, 90, and 9 arranged near the four corners of 0
2, 94 respectively. With the above configuration, music can be enjoyed in the listening room 50 in an atmosphere as if it were in an actual sound field space.

[0007]

In the conventional apparatus,
In order to provide a sound field effect, at least four speakers were required as described above. Further, in order to obtain a feeling of the spread of the sound field, it is necessary to reduce the correlation between the direct sound and the reflected sound. And had to deal with the reflected sound with a long delay time. Also, as another method,
The spread can be obtained by slightly changing the left and right pitches by using a means for changing the pitch, but the effect in this case should be called a diffusion effect, and a three-dimensional effect cannot be obtained.

The present invention is intended to solve the above-mentioned problems in the prior art, and to provide a sound field control device capable of creating a sound field having a three-dimensional feeling and a spacious feeling with at least two speakers. Is what you do.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a reflected sound signal to be emitted at the left and right positions in front of a listening point and a position behind the listening point to reproduce a large number of reflected sounds of a source signal around the listening point. In each of the generated reflected sound signals to be emitted, the reflected sound signal to be emitted at a position behind the listening point, subjected to a phase shift processing that changes the phase according to the frequency,
Two phase-shifted signals having a phase difference of approximately 180 degrees from each other are generated, and the reflected sound signal to be emitted at the front left position and one of the phase-shifted signals are added, and the reflected sound signal to be emitted at the front right position and the other. And the speakers disposed at the front left and right positions of the listening point are driven based on these two added signals.

[0010]

According to the present invention, since the reflected sound to be emitted at the front left and right positions is directly emitted from the front left and right positions, the sound is properly localized forward and a sound field feeling is obtained ahead. In addition, the reflected sound to be emitted at the rear is made into two reflected sounds having phases opposite to each other and emitted from the left and right positions, so that an in-head localization (a phenomenon in which a sound image is felt around the head) is obtained, and a pseudo backward sound is obtained. Thus, a sense of sound field up to the rear can be obtained with only the front two channels. In this case, if the reflected sound of the opposite phase is too conspicuous, an unpleasant feeling of reversed phase will occur.However, it will be masked by the reflected sound that is correctly localized in the front, and will be less noticeable. A feeling of the sound field can be obtained.

In addition, in the reflected sound obtained by merely delaying the direct sound, the similarity is high only due to the time difference from the direct sound, but in the present invention, the phase is changed according to the frequency by the phase shift processing. Therefore, the waveform similarity with the direct sound is reduced. Therefore, a very large back-and-forth feeling can be obtained even with a small amount of reflected sound processing and a short-time reflected sound, and a three-dimensional effect and a spaciousness can be increased. Even in this case, since only the phase is changed, the high-frequency component is not changed, so that a change in timbre and an increase in distortion are not caused.

Further, by performing the convolution operation using the impulse response characteristics based on the virtual sound source distribution to generate the reflected sound, it is possible to realize a sound field having an atmosphere close to various sound fields with speakers arranged in front and left and right. As a result, the sense of presence in audio reproduction of a normal two-speaker stereo system cassette deck with radio, an electronic musical instrument, a game machine, etc. is improved.

[0013]

An embodiment of the present invention will be described below. FIG. 1 shows the outline. Left and right two channel source signals L, R
Are combined by the mixer 30 into one channel of LR or L + R. The source signal synthesized into one channel is
The signals are input to delay circuits (reflected sound generation circuits) 2, 4, and 6.
The delay circuits 2, 4, and 6 perform a convolution operation of the reflected sound parameter and the source signal or other reflected sound generation processing, thereby obtaining the front left (FL), front right (FR), and rear left and right (RL + RR). Each reflected sound signal is generated.
Front left and right reflected sound signals F output from the delay circuits 2 and 4
L and FR are added to the left and right source signals L and R (main signal (direct sound)) by adders 104-1 and 104-2, respectively. The rear left and right reflected sound signals RL + RR output from the delay circuit 6 are input to the phase shift circuit 100. The phase shift circuit 100 performs a phase shift process of changing the phase according to the frequency by the phase shifter 114 and a process of inverting the phase by 90 ° by the phase inverter 118, so that the phase difference is substantially equal to each other. 180 ° and almost the same level 2
Two reflected sound signals R _{+ 90} and R- ₉₀ are created. These reflected sound signals R _{+ 90} and R- ₉₀ are added to adders 104-2 and 106-2.
, Are added to the left and right signals L + FL and R + RL, respectively, and output.

FIG. 4 shows a configuration example of the phase shift circuit 100 of FIG. The rear left and right reflected sound signals RL + RR are
After the DC component is removed at 10, the phase shifter 11 composed of inverting amplifiers 113 and 115 is passed through the inverting amplifier 112.
In step 4, a process of changing the phase according to the frequency is performed, and further, the inverted reflected signal is inverted by the inverting amplifier 118 to generate two reflected sound signals R _{+ 90} and R- ₉₀ having a phase difference of approximately 180 degrees from each other. .

FIG. 5 shows frequency characteristics of gain and phase of the phase shift circuit of FIG. According to this, the gain is between A → B, A
The characteristic is flat between → C, and the characteristic that the phase changes according to the frequency while always maintaining a phase difference of 180 ° between A → B and A → C is obtained.

When the output signal of the sound field control device 16 shown in FIG. 1 is reproduced by two speakers arranged in front of and right and left of the listener,
The main signals (direct sounds) L and R are correctly localized forward. The reflected sound signals FL, F to be emitted at the front left and right positions
Since R is reproduced from the front left and right positions as it is, it is correctly localized forward, and a sound field feeling is obtained ahead. Also, the reflected sound signal RL + RR to be emitted at the rear is reproduced from the left and right positions as two reflected sound signals R _{+ 90} and R- ₉₀ having _phases opposite to each other. Is obtained,
As a result, a sound field feeling to the rear can be obtained with only the front two-channel speakers. Also, the reflected sounds due to the reflected sound signals R ₊₉₀ and R ₋₉₀ having opposite phases are masked by the right and left reflected sounds that are correctly localized in front and become less noticeable, so that an unpleasant feeling of reversed phase is reduced. A natural sound field feeling can be obtained.

Further, by performing a phase shift process in which the phase changes according to the frequency in the phase shift circuit 100, the following sound effects can be obtained according to the type of sound.

(A) Since the sound of the rhythm instrument among the input sounds is a discontinuous sound, the direct sound and the reflected sound have little overlap. Therefore, the fundamental part is localized relatively clearly.

(B) In a musical instrument having a continuous sound such as a violin, a direct sound, a forward reflected sound, and a back reflected sound are simultaneously overlapped and heard. The effect of the process of reducing the similarity of the front and rear waveforms in this way of hearing is such that even if the delay time of the reflected sound is short, a large front and back feeling can be obtained.

(C) More various operations are performed on sounds that are continuous and whose pitch and intensity are modulated with time in order to make a change, such as the sound of a synthesizer of an electronic musical instrument. In the case of a sound whose pitch changes with time, the waveform of the output of the phase shift circuit 100 changes according to the frequency change, and the similarity of the waveform also changes with time. In this case, an extremely wide sense of non-orientation in front, rear, left, and right directions can be obtained.

In any of the above cases, only the phase changes, so that the high-frequency component does not change, and therefore no change in timbre and no increase in the sense of distortion occurs. Even with a small amount of reflected sound processing and a short period of reflected sound, a very large scale back-and-forth feeling can be obtained and the three-dimensional effect can be increased.

As described above, according to the present invention, by performing the phase shift processing in which the phase changes in accordance with the frequency, the effect is different depending on the character of the musical instrument. For example, it is possible to realize a sound field expression in which the rhythm instrument is clearly displayed while the sound of the synthesizer is widely spread in the background, and variously separated. In addition, since there is basically no dependence on the length of the delay time or the number of reflected sounds, a great effect can be obtained with an inexpensive and simple circuit. It should be noted that the effects of the present invention can be obtained in a case where the front reflected sound is only one channel or a case in which the front reflected sound is eliminated for further simplification.

(Specific Example 1) A specific example of the sound field control device 16 of FIG. 1 will be described. Here, a case where the reflected sound is generated by a convolution operation using an impulse response characteristic based on the same virtual sound source distribution as shown in FIG. 2 will be described. FIG. 6 shows the configuration. The system shown in FIG. 6 can be constituted by a single device including, for example, a speaker as a cassette deck with a two-speaker stereo radio.

The left and right two-channel source signals L and R transmitted from the source device 10 are input to the sound field control device 16 via the input terminals 12 and 14. Sound field control device 16
Here, the stereo pre-
The input source signals L and R are transmitted through a preamplifier 18 to a reflected sound signal generation unit 2.
8 (sound field effect processor). The source signals L and R input to the reflected sound signal generation means 28 are
At 0, the signal is synthesized into one channel of LR or L + R.
The source signal synthesized into one channel is passed through a low-pass filter 32 for preventing aliasing at the time of A / D conversion, and is then subjected to A / D conversion.
The signal is converted into a digital signal by the / D converter 34. Further, in order to give a frequency characteristic to the reflected sound, the digital sound is branched into digital channels 36, 38, 40,
42. Digital filters 36, 38, 4
The source signals output from 0 and 42 are input to reflected sound generation circuits 44, 46, 48 and 50 of each channel.

The ROM 52 stores various sound spaces (such as halls, studios, jazz clubs, churches, karaoke rooms, etc.) as parameters of various sound field effect modes, for example, as shown in FIG. ) Is stored for each direction. The reflected sound generation circuits 44, 46, 48, and 50 perform convolution calculation with the source signal based on the reflected sound parameter of one mode arbitrarily selected from the reflected sound parameters stored in the ROM 52. ,
The reflected sound signal of the source signal is generated for each channel. These generated reflected sound signals are D / A converted by the D / A converter 54 in a time division multiplex manner. D / A
The output signal of the converter 54 is distributed to each channel, smoothed by low-pass filters 56, 58, 60, and 62, returned to an analog signal, and output from the reflected sound signal generation means 28.

The reflected sound signals RL and RR on the left and right sides of the reflected sound signals in the four directions are added by an adder 96, and then subjected to a phase shift process in which the phase changes according to the frequency in a phase shift circuit 100. Thus, two reflected sound signals R ₊₉₀ and R _-90 having a phase difference of approximately 180 ° and a substantially same level are generated. These reflected sound signals R _{+ 90} and R- ₉₀ are added to the adder 104.
(Combined adders 104-1 and 104-2 in FIG. 1) and 106 (combined adders 106-1 and 106-2 in FIG. 1) apply to the front left and right reflected sound signals FL and FR, respectively. Is added. Further, in the adders 104 and 106, the left and right source signals L and R (main signals) are added, and each added output is guided to speaker output terminals 72 and 74 via power amplifiers 64 and 66. Output terminal 24,
The left and right two-channel signals guided to the speaker 26 are output from a speaker 8 disposed in front of a listening point 82 of a listening room 80.
4, 86 (loudspeakers such as a cassette deck with a radio). As a result, both the main signal and the reflected sound signal are reproduced from the main speakers 84 and 86 in a state where a three-dimensional effect and a spaciousness are obtained. Further, in the specific example of FIG. 6, since the reflected sound is generated by the convolution operation using the impulse response characteristics based on the virtual sound source distribution, as is apparent from FIG. As soon as the sound arrives early, the sound is largely dominated by the front reflected sound that arrives early in human hearing, and the sense of reverse phase due to the back reflected sound can be further reduced to obtain a more natural sound field feeling.

As shown by a dotted line in FIG. 6, power amplifiers 20 and 22 and main signal output terminals 24 and 26 are provided on a main signal transmission line, and a main signal output terminal 2 is provided.
A separate speaker can be connected to each of the speakers 4 and 26 so that the main signal can be reproduced from this speaker. In this case, the supply of the main signal in the adders 104 and 106 can be stopped by a switch or the like.

(Specific Example 2) Another specific example of the sound field control device 16 of FIG. 1 is shown in FIG. This is disclosed in
The present invention is applied to a device described in Japanese Patent Application Publication No. 0-205, which generates a reflected sound signal by applying different reflected sound parameters to the sum signal L + R and the difference signal LR of the main signals L and R. The adder 110 obtains a sum signal L + R of the main signals L and R and inputs the sum signal L + R to the reflected sound generation unit 112.
Further, the subtractor 114 outputs a difference signal L−R between the main signals L and R.
Is input to the reflected sound generation unit 116. The reflected sound generation units 112 and 116 are, for example, the LPF 32 of FIG.
D converter 34, digital filters 36, 38, 40,
42, each of which includes a reflected sound generation circuit 44, 46, 48, 50, and performs a convolution operation using the reflected sound parameters stored in the ROMs 118, 120 to generate reflected sound signals, respectively. Here, since the sum signal L + R is a centrally located component such as a conversation, a reflected sound parameter applied to the sum signal L + R has a pattern that provides a relatively narrow sound field. Further, since the difference signal LR is a non-centered localization component, a reflected sound parameter applied to the difference signal LR has a pattern that provides a sound field having a relatively broad feeling.

The reflected sound signals output from the reflected sound generators 112 and 116 are added to adders 122, 124, 126 and 12 respectively.
8, the corresponding channels are added, and D
In the / A converter 54, D / A conversion is performed in a time division multiplex manner. The output signal of the D / A converter 54 is distributed to each channel and the low-pass filters 56, 58, 60, 6
2, the signal is returned to an analog signal and output from the reflected sound signal generating means 28.

The reflected sound signals RL and RR on the left and right sides of the reflected sound signals in the four directions are added by an adder 96, and then subjected to a phase shift process in which the phase changes according to the frequency in a phase shift circuit 100. Thus, two reflected sound signals R ₊₉₀ and R _-90 having a phase difference of approximately 180 ° and a substantially same level are generated. These reflected sound signals R _{+ 90} and R- ₉₀ are added to an adder 104,
At 106, they are added to the front left and right reflected sound signals FL and FR, respectively. Further, in the adders 104 and 106, the left and right source signals L and R (main signals) are added, and each added output is guided to speaker output terminals 72 and 74 via power amplifiers 64 and 66. The left and right two-channel signals guided to the output terminals 24 and 26 are output to the listening room 80.
Speakers 84 and 86 arranged in front of the listening point 82
(A speaker such as a cassette deck with a radio). As a result, both the main signal and the reflected sound signal are reproduced from the main speakers 84 and 86. As described above, by using the two types of reflected sound parameters, it is possible to give an appropriate sound field feeling to a centrally located component such as a conversation and to give a rich sense of spread to a non-centralized component.

(Embodiment 3) FIG. 8 shows still another embodiment of the sound field control device 16 of FIG. This is disclosed in JP-A-4-15.
The present invention is applied to an apparatus described in Japanese Patent Application Laid-Open No. 0200, which performs reflected sound generation capable of giving a feeling of surroundings as in a 70 mm screening hall.

From the source device 10, Dolby Surround (trademark) is used as source signals L and R for left and right channels.
An encoded playback signal from an LV (laser vision disc) player, a VTR, or the like is output to an input terminal 1
2, 14 are inputted. The direction emphasis circuit 130 determines the level of the input L, R and L + R, LR, and controls the level of each channel according to the result. , S are output.

Of these four channel signals, L,
R and C are generated as L + C (or L + C / 2) in an adder 132 as main signals, and R + C is generated in an adder 134.
(Or R + C / 2) is created.

The main signal M is added and synthesized by the synthesizing means 136 and input to the main sound field signal generating means 138.
The main sound field signal forming means 138, and a convolution operation using the reflected sound parameters P1 read from the ROM 140, to create a reflected sound signal M ₀ giving the first sound field for the main signal M.

In order to enjoy the atmosphere of the 70 mm screening hall, the reflected sound parameter P1 is localized on the front screen side as a front screen side sound field, and a relatively tight sound field where sound effects and music are spread deep in the screen. Is suitable. The reflected sound generation unit 142 includes, for example, the LPF 32, the A / D converter 34, the digital filters 36, 38, 40, and 42 of FIG.
4, 46, 48 and 50.
A convolution operation is performed using the reflected sound parameter P1 stored in ₀ to generate a reflected sound signal M ₀ (main sound field signal).

On the other hand, the surround signal S output from the directivity emphasis circuit 130 is
4. Modified Dolby B type noise reduction 14
6, and is input to the surround sound field signal generating means 150 via a delay circuit 148 of 15 to 30 mmsec.

The surround sound field signal generating means 150
The convolution operation is performed using the reflected sound parameter P2 read from the OM 152, and the second
Sound signal S ₀ (surround sound field signal) that gives the sound field of
And the main sound field signal generating means 1
38, a reflected sound generation unit 154 having the same configuration as that of the first embodiment. In order to enjoy the atmosphere of the 70-mm screening hall, the reflected sound parameter P2 is suitable as a surround sound field that provides a vast sound field localized around the listener as a surround sound field.

The main sound field signal M ₀ and the surround sound field signal S ₀ generated by the main sound field signal generating means 138 and the surround sound field generating means 150 are added to the adders 156, 1
At 58, 160 and 162, the corresponding channels are added and synthesized. The synthesized reflected sound signal M ₀ + S ₀ is D /
The A / D converter 54 performs D / A conversion in a time division multiplex manner. The output signal of the D / A converter 54 is distributed to each channel and the low-pass filters 56, 58, 60, 6
2, the signal is returned to an analog signal and output from the reflected sound signal generating means 28.

The reflected sound signals RL and RR on the left and right sides of the reflected sound signals in the four directions are added by an adder 96, and then subjected to a phase shift process in which the phase is changed according to the frequency by a phase shift circuit 100. Thus, two reflected sound signals R ₊₉₀ and R _-90 having a phase difference of approximately 180 ° and a substantially same level are generated. These reflected sound signals R _{+ 90} and R- ₉₀ are added to an adder 104,
At 106, they are added to the front left and right reflected sound signals FL and FR, respectively. Further, in the adders 104 and 106, the left and right source signals L and R (main signals) are added, and each added output is guided to speaker output terminals 72 and 74 via power amplifiers 64 and 66. The left and right two-channel signals guided to the output terminals 24 and 26 are output to the listening room 80.
Speakers 84 and 86 arranged in front of the listening point 82
(A speaker such as a cassette deck with a radio). As a result, both the main signal and the reflected sound signal are reproduced from the main speakers 84 and 86. In this way, a movie or the like can be watched while enjoying the atmosphere of a 70 mm screening theater.

[0040]

[Modification] In each of the above embodiments, parameters in four directions of front left, right, rear and left and right are used as reflected sound parameters, but as shown in FIG.
If the reflected sound parameter of L + RR is prepared in the ROM 166 in advance, the reflected sound generation circuit can be used for the FL 168 and the FR 1
70, RL + RR 172 only simplifies the configuration.

The rear reflected sound signal is not the sum of the rear left and right reflected sound signals, but may be a unique reflected sound parameter of the reflected sound signal to be emitted at the rear center position.

In the above-described embodiment, the case where the reflected sound is generated by the convolution operation using the impulse response characteristic based on the virtual sound source distribution has been described. However, in order to reproduce a large number of reflected sounds around the listening point, the reflected sound is generated. The present invention can be applied to various reflected sound signal generation schemes for generating a reflected sound signal of a source signal to be emitted at the left and right positions in front of the listening point and a reflected sound signal of a source signal to be emitted at a position behind the listening point.

Further, the phase shifting means is not limited to the one shown in the above-mentioned embodiment, but may be of any other type which performs a phase shifting process in which the phase changes according to the frequency.

[0044]

As described above, according to the present invention, since the reflected sound to be emitted from the front left and right positions is directly emitted from the front left and right positions, the sound is properly localized forward and a sound field feeling is obtained ahead. In addition, the reflected sound to be emitted at the rear is made into two reflected sounds of opposite phases to each other and emitted from the left and right positions, thereby localizing in the head (a phenomenon in which a sound image is felt around the head).
And a pseudo backward feeling is obtained.
The sound field feeling to the rear can be obtained only by the channel. In this case, if the reflected sound of the opposite phase is too conspicuous, an unpleasant feeling of reversed phase will occur.However, it will be masked by the reflected sound that is correctly localized in the front, and will be less noticeable. A feeling of the sound field can be obtained.

In the reflected sound obtained by simply delaying the direct sound, the similarity is high only because of the time difference from the direct sound. However, in the present invention, the phase is changed in accordance with the frequency by the phase shift processing. Therefore, the waveform similarity with the direct sound is reduced. Therefore, a very large back-and-forth feeling can be obtained even with a small amount of reflected sound processing and a short-time reflected sound, and a three-dimensional effect and a spaciousness are enhanced. Even in this case, since only the phase is changed, the high-frequency component is not changed, so that a change in timbre and an increase in distortion are not caused.

Further, by generating the reflected sound by a convolution operation using an impulse response characteristic based on a virtual sound source distribution, it is possible to realize a sound field having an atmosphere close to various sound fields with speakers arranged in front and left and right. As a result, the sense of presence in audio reproduction of a normal two-speaker stereo system cassette deck with radio, an electronic musical instrument, a game machine, etc. is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a conventional device.

FIG. 3 is a diagram showing an example of reflected sound parameters stored in a ROM 52 of FIGS. 1 and 2;

FIG. 4 is a circuit diagram showing a specific example of the phase shift circuit 100 of FIG.

FIG. 5 is a diagram illustrating gain and phase characteristics with respect to frequency of the phase shift circuit 100 of FIG. 4;

FIG. 6 is a block diagram showing a specific example of the sound field control device 16 of FIG.

FIG. 7 is a block diagram showing another specific example of the sound field control device 16 of FIG.

8 is a block diagram showing still another specific example of the sound field control device 16 in FIG.

FIG. 9 is a block diagram showing a modified example of the reflected sound signal generation means and a diagram showing reflected sound parameters.

[Explanation of symbols]

Reference Signs List 16 sound field control device 28 reflected sound signal generation means 82 listening point 84, 86 speaker 100 phase shift circuit (phase shift means) 104, 106 adders (first addition means, second addition means) L, R source signals FL, FR, RL, RR Reflected sound signal R _{+ 90} , R- ₉₀ phase-shifted signal (first phase-shifted signal, second phase-shifted signal)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-55-27705 (JP, A) JP-A-5-260597 (JP, A) JP-A-5-207597 (JP, A) 127700 (JP, A) JP-A-4-281700 (JP, A) JP-A-2-150900 (JP, U) JP-A-4-61997 (JP, U) JP-A-63-52400 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H04S 1/00 G10K 15/00 H04S 5/02

Claims (3)

(57) [Claims] To reproduce a large number of reflections of a source signal around a listening point, the sound should be emitted at the left and right positions in front of the listening point.
A reflected sound signal generation means for generating a reflected sound signal of the reflected sound signal and the source signal to be emitted at a rearward position of the listening point of the source signal, respectively, the reflection sound signal to be emitted at a rearward position of the listening point ,
A outputs a first phase shift signal and the second phase shift signal by performing phase processing phase changes in accordance with the frequency
The phase of the first and second phase-shifted signals.
Phase shifting means for performing the phase shifting processing so that the difference becomes approximately 180 ° ; a reflected sound signal to be emitted at a front left position of the reflected sound signal; and a first phase shifted signal among outputs of the phase shifting means. Adding means for adding a reflected sound signal to be emitted at a front right position of the reflected sound signal and a second phase-shifted signal among outputs of the phase-shifting means. A sound field control device comprising: driving speakers arranged at the front left and right positions of the listening point based on output signals of the first and second adding means. 2. A method for reproducing a large number of reflected sounds in the acoustic space or a model space similar to the acoustic space around a listening point based on reflected sound data obtained corresponding to each virtual sound source position of the reflected sound in the acoustic space. The source signal is convoluted with respect to the impulse response characteristics of the reflected sounds to be emitted at the front left and right positions and the rear left and right positions of the listening point, and the respective reflected sounds of the source signal to be emitted at the front and left positions of the listening point Signal and the corresponding source signal to be emitted at the rear left and right positions
A reflected sound signal generation means for generating respectively a sum signal of the reflected sound signal, the relative sum signal, a first phase shift signal and the second transferring is subjected to phase shift processing phase changes in accordance with the frequency And outputs a first phase shift signal and a second phase signal.
2 so that the phase difference with the phase shift signal of FIG.
Phase shifting means for performing a phase shifting process; first adding means for adding a front left reflected sound signal of the reflected sound signals and a first phase shifted signal of the output of the phase shifting means; A second adder for adding a front right reflected sound signal of the sound signal and a second phase shift signal of the output of the phase shifter; and an output of the first and second adder. A sound field control device for driving speakers arranged at right and left positions in front of the listening point based on a signal. 3. The first adding means includes at least a left signal of the source signal, a front left reflected sound signal of the reflected sound signal, and a first shifted signal of an output of the phase shifting means. Phase signal, and the second adding means determines at least a right signal of the source signal, a front right reflected sound signal of the reflected sound signal, and a second signal of the output of the phase shifting means. The sound field control device according to claim 1, wherein the phase shift signal is added to the sound field control signal.