JPH06261397A - Sound field signal reproducing device - Google Patents

Abstract

PURPOSE:To generate a natural spread sense without a sense of opposite phase and to produce the plural types of sound fields by convoluting reflection sounds separately on the sum signal and difference signal of a stereo signal. CONSTITUTION:An input means inputs a stereo signal, and a multiplier 3-1 and an adder 4-1 extract the difference signal between the L and R channel signals of the inputted stereo signal. An adder 4-2 generates the sum signal between L and P channel signals of the inputted stereo signal. Convoluting processing means 13-1 and 13-2 perform convoluting processing on the branched respective difference signals. Convoluting processing means 13-3 and 13-4 perform convoluting processing on the respective generated sum signal. Adders 4-3 and 4-4 add the processing results of the means 13-1 and 13-2 and the processing results of the means 13-3 and 13-4, and then the two output means outputs the addition result. Thus, the sound field with different convoluted reflection sounds can be reproduced in the signal outputted from the two output terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound field signal reproducing apparatus for reproducing realistic sound in AV (audio / visual) equipment.

[0002]

2. Description of the Related Art In recent years, VTRs have been used in the video and audio fields.
Due to the spread of, it is desired to have a large screen and realistic sound reproduction in order to enjoy movies at home, and not only movies but also realistic sound reproduction to enjoy music software,
It is necessary to develop hardware to support this.

A conventional sound field signal reproducing device will be described below with reference to the drawings. FIG. 4 is a hardware block diagram showing a configuration of a conventional sound field signal reproducing device. 4, 1 and 2 are input terminals, 3 is a multiplier for multiplying by -1, 4 is an adder, 5 is a delay device, 6 is a multiplier, 7 and 9 are adders, 8 is a multiplier, 10 and 11 Is the output terminal, L (t)
(T represents a continuous time, and L (t) represents a time function. The same applies hereinafter) is an L channel signal of a stereo audio signal, and R (t) is an R channel of a stereo audio signal. A signal, τ is a delay time in the delay device 5, and a is a coefficient of the multiplier 6.

The operation of the conventional sound field signal reproducing device configured as described above will be described with reference to FIG.

First, L (t) is input from the input terminal 1, and R (t) is input from the input terminal 2. The input signal is branched into two, L (t) is input to the adder 4 and the adder 7, and R (t) is input to the multiplier 3 and the adder 9. In the multiplier 3, R (t) is multiplied by -1, and the result, -R (t), is input to the adder 4. In the adder 4, L (t) and -R (t) are added, and as a result, L (t) -R (t) is output and L (t)
-R (t) is input to the delay device 5. In the delay device 5, L
(T) -R (t) is delayed by time τ to obtain L (t-τ)
-R (T-τ) is output. The output of the delay device 5 is the multiplier 6
To L (t-τ) -R (t-τ) in the multiplier 6.
Is multiplied by a to output a (L (t−τ) −R (t−τ)).

The output from the multiplier 6 is divided into two, one of which is input to the adder 7 and the other of which is input to the multiplier 8. In the multiplier 8, a (L (t-τ) -R (t -Τ)) is multiplied by -1 and the result is -a (L (t-τ) -R
(T−τ)) is input to the adder 9.

In the adder 7, L (t) and a (L (t-τ))
-R (t-τ)) is added and the result is L
(T) + a (L (t−τ) −R (t−τ)) is output from the output terminal 10. In the adder 9, R (t) and -a (L
(T-τ) -R (t-τ)) is added, and the result R (t) -a (L (t-τ) -R (t-τ)) is output from the output terminal 11. To be done. When the output from the output terminals 10 and 11 is reproduced by a two-channel speaker, a (L (t-τ) -R (t-
τ)) and from the other side -a (L (t-τ) -R (t-
τ)), which are opposite in phase to each other, are mixed and reproduced, thereby generating a sound field in which the localization of the sound image is unknown. Then, by adjusting the mix balance with L (t) and R (t), which are direct sounds that have not been subjected to any processing, a sound field with a sense of spaciousness and a sense of presence is generated.

[0008]

However, in the above-described configuration, adjustment is performed by the mix balance of the anti-phase sound and the direct sound, and the effect is small when the anti-phase sound is small, and the effect can be seen. On the other hand, when the anti-phase sound is increased, the anti-phase feeling becomes strong and the discomfort is brought. Therefore, there has been a demand for the development of a sound field signal reproducing device that can generate a natural sense of expanse without sense of antiphase. There is also a demand for the sound field signal reproducing device to be able to generate plural kinds of sound fields.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sound field signal reproducing apparatus capable of generating a natural sense of expanse without sense of antiphase and capable of generating a plurality of kinds of sound fields. To do.

[0010]

The present invention comprises input means for inputting a stereo signal, difference signal extraction means for extracting a difference signal between the L channel signal and the R channel signal of the input stereo signal, and Sum signal generation means for generating a sum signal of the L channel signal and the R channel signal of the input stereo signal, difference signal branch means for branching the extracted difference signal into at least two signals, and the generated Sum signal branching means for branching the sum signal into at least two signals, at least two difference signal convolution processing means for performing convolution processing on each of the branched difference signals, and convolution processing for each of the generated sum signals At least two sum signal convolution processing means, a processing result of the difference signal convolution processing means, and a processing result of the sum signal convolution processing means At least two adding means for adding, those having at least two output means for outputting the addition result of the adding means.

[0011]

In the present invention, the input means inputs a stereo signal,
The difference signal extracting means extracts a difference signal between the L channel signal and the R channel signal of the input stereo signal, and the sum signal generating means generates a sum signal of the L channel signal and the R channel signal of the stereo signal input. Then, the difference signal branching means branches the extracted difference signal into at least two signals, and the sum signal branching means divides the generated sum signal into at least two signals.
One signal and at least two difference signal convolution means perform convolution processing on each of the divided difference signals,
At least two sum signal convolution processing means perform convolution processing on each of the generated sum signals, and at least two addition means add the processing result of the difference signal convolution processing means and the processing result of the sum signal convolution processing means. , At least two output means output the addition result of the addition means.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a hardware block diagram of a sound field signal reproducing apparatus according to the first embodiment of the present invention. Figure 1
, 12-1 and 12-2 are A / D converters that convert the input analog signals into digital signals, 3-1 is a multiplier that multiplies the output from the A / D converter 12-2 by -1, 4-1 is an adder for adding the output from the A / D converter 12-1 and the output from the multiplier 3-1. 4-2 is the output from the A / D converter 12-1 and the A / D conversion. Adders for adding the outputs from the adder 12-2, 13-1 and 13-2 are adders 4
Convolution processing means for performing convolution processing on the output of -1;
3-3 and 13-4 are convolution processing means for performing convolution processing on the output of the adder 4-2, and 4-3 is an A / D converter 12-.
An adder for adding the output from 1 and the output of the convolution processing means 13-1 and the output of the convolution processing means 13-3, 4-
4 is an adder for adding the output from the A / D converter 12-2, the output of the convolution processing means 13-2 and the output of the convolution processing means 13-4, and 14-1 is the output from the adder 4-3. D / A that converts a digital signal that is an analog signal
A converter 14-2 is a D / A converter for converting the digital signal output from the adder 4-4 into an analog signal, L
(N) is obtained by converting L (t) into a digital signal whose time is discrete (t = nT when the sampling period of the digital signal is T. Usually, when expressing a discrete signal, L (n) or the like is used. The same applies hereinafter), and R (n) is R
(T) is converted into a digital signal. The same functions as those in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted.

The operation of the sound field signal reproducing apparatus of the first embodiment constructed as above will be described with reference to FIG.

First, L (t) is input from the input terminal 1, R (t) is input from the input terminal 2, and the input L (t) is input.
(T) and R (t) are A / D converters 12-1 and 1 respectively.
2-2 is input. The A / D converter 12-1 converts the analog signal L (t) into a digital signal L (n),
The / D converter 12-2 converts the analog signal R (t) into a digital signal R (n). L (n) is branched into three, one is input to the adder 4-1, the other is input to the adder 4-2, and the other is input to the adder 4-3. R (n) is also branched into three, one is input to the adder 4-2, the other is input to the multiplier 3-1 and the other one is input.
One is input to the adder 4-4.

The adder 4-2 adds L (n) and R (n), and outputs the result, L (n) + R (n). That is, the adder 4-2 constitutes the sum signal generating means. The output from the adder 4-2 is branched into two and inputted to the convolution processing means 13-3 and 13-4, respectively.
The convolution processing means 13-3 and 13-4 respectively have L
Convolution processing is performed on (n) + R (n), and the results are input to adders 4-3 and 4-4, respectively. On the other hand, in the multiplier 3-1, R (n) is multiplied by -1, and the result, -R (n), is input to the adder 4-1, and the adder 4-1 is added.
In, the addition of L (n) and -R (n) is performed and the result L (n) -R (n) is output. That is, the multiplier 3-
1 and the adder 4-1 form a difference signal extracting means. The output from the adder 4-1 is branched into two and inputted to the convolution processing means 13-1 and 13-2, respectively, and the convolution processing means 13-1 and 13-2 respectively have L (n) -R.
Convolution processing is performed on (n), and the results are input to adders 4-3 and 4-4, respectively. In the adder 4-3, the outputs from the convolution processing means 13-3 and 13-1 and L (n)
Are added and the result is input to the D / A converter 14-1. In the adder 4-4, the convolution processing means 13-
4, the output from 13-2 and R (n) are added,
The result is input to the D / A converter 14-2. D / A
The converters 14-1 and 14-2 convert the input digital signals into analog signals, and the results are output from the output terminals 10 and 11, respectively. The output signal is reproduced from a speaker or the like.

Hereinafter, the convolution processing means 13-1, 13-
2, 13-3 and 13-4 will be described in detail. Figure 2
FIG. 3 is a hardware block diagram of convolution processing means. In FIG. 2, 15 is an input terminal, 16-1, 16-
2, 16-3, ..., 16-m are delay devices, 17-1,
17-2, 17-3, ..., 17-m are multipliers, 18
Is an adder, 19 is an output terminal, D (n) is a digital signal input to the convolution processing means, n ₁ , n ₂ , n ₃ , ...
·, N _m is the delay device 16-1, ...
, A value obtained by dividing the delay time at 16-m by the sampling period, that is, a value indicating how many sampling periods are delayed, and a ₁ , a ₂ , a ₃ , ..., _Am are multipliers. 17-
The coefficients are 1, 17-2, 17-3, ..., 17-m.

The operation of the convolution processing device will be described with reference to FIG. A digital signal is input from the input terminal 15, and the input digital signal will be described below as D (n). However, the convolution processing means 13 in FIG.
-1, 13-2, D (n) = L (n) -R (n)
Therefore, in the case of the convolution processing means 13-3 and 13-4,
D (n) = L (n) + R (n). D entered
(N) is divided into m signals, each of which has a delay device 16-
1, 16-2, 16-3, ..., 16-m. Delay devices 16-1, 16-2, 16-3, ..., 1
In 6-m, the input D (n) is n ₁ , n ₂ , and n, respectively.
₃ , ..., N _m sampling periods are delayed, and the resulting D (n-n ₁ ), D (n-n ₂ ), D (n-n)
₃ ), ..., D (n- _nm ) are respectively multiplied by a multiplier 17-
1, 17-2, 17-3, ..., 17-m.

Multipliers 17-1, 17-2, 17-3, ...
.., 17-m, the input D (n-
n₁), D (n-n₂), D (n-n₃), ..., D
(N-n_m) To a₁, A₂, A₃,, a_mTo
Multiplied by each, the result a₁・ D (n-n₁),
a₂・ D (n-n₂), A₃・ D (n-n₃), ... a
_m・ D (n-n_m) Is output to the adder 18. Adder 18
Then input a₁・ D (n-n₁), A₂・ D (n-
n₂), A₃・ D (n-n₃), ... a_m・ D (n-n
_m) Is added and the result is a₁・ D (n-n₁) +
a₂・ D (n-n₂) + A₃・ D (n-n₃) + ... + a
_m・ D (n-n_m) Is output from the output terminal 19. this
Thus, the D (n) input to the convolution processing means is
If it is a direct sound, n₁sampling
A cycle later₁For reflected sound of doubled volume and direct sound
For n₂Delayed by the sampling period a₂Anti-doubled volume
N for shooting sound and direct sound₃Delayed by the sampling period
a₃N for the reflected sound of doubled volume, similarly for direct sound_m
Delayed by the sampling period a_mThe reflected sound of the doubled volume
The m reflected sounds are folded in. Also, n₁, N₂,
n₃, ..., n_m, And a₁, A₂, A ₃,, a_mof
Folds various types of reflected sound by changing the value
Can be crowded.

As described above, the four convolution processing means are provided, and the reflected sound is separately convoluted into the sum signal and the difference signal of the stereo signal, so that there is no sense of antiphase and there is a natural expansive and realistic sound field. It is also suitable for adding the initial reflected sound, because the reflected sound can be reproduced and the reflected sound is convoluted into the sum signal. Generally, a reverberation component is often extracted from the difference signal of the stereo signals, and it is suitable to perform the convolution process using the sum signal of the stereo signals to add the initial reflected sound. In addition, since two convolution processing means are provided for each of the sum signal and the difference signal of the stereo signal, the signals output from the two output terminals 10 and 11 have different convolved reflected sounds. The field can be reproduced, that is, reflected sound can be added in stereo. Further, by changing the delay amount of the delay device and the coefficient of the multiplier in the convolution processing means, it is possible to generate a plurality of types of sound fields such as a sound field with rich resonance and a sound field with few reflected sounds. Further, since the reflected sound can be convolved by making use of the characteristics of the sum signal and the difference signal of the stereo signal, it is possible to reproduce a wider variety of sound fields.

In this embodiment, adders 4-5, 4-
There is no multiplier for adjusting the mix balance when performing the addition at 6, but the convolution processing means 13-1 and 13
-2, 13-3, 13-4 and adders 4-5, 4-6 are respectively provided with multipliers, or adders 4-1 and 4
-4 is followed by a multiplier, and L (n), R (n)
It may be possible to adjust the mix balance between the signal and the signal after the convolution processing.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a hardware block diagram of a sound field signal reproducing apparatus according to the second embodiment of the present invention. In FIG. 3, 4-5, 4-6, 4-7, 4-8
Is an adder, and 8-1 is a multiplier that multiplies by -1. The same functions as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

The operation of the sound field signal reproducing apparatus according to the second embodiment having the above configuration will be described with reference to FIG.

First, L (t) is input from the input terminal 1 and R (t) is input from the input terminal 2. The input L (t) and R (t) are A / D converter 12-1, respectively.
It is input to 12-2. The A / D converter 12-1 converts the analog signal L (t) into a digital signal L (n),
The A / D converter 12-2 converts the analog signal R (t) into a digital signal R (n). L (n) is branched into three, one is input to the adder 4-1, the other is input to the adder 4-2, and the other is input to the adder 4-7. R (n) is also branched into three, one of which is an adder 4-2.
, The other is input to the multiplier 3-1 and the other is input to the adder 4-8. L in the adder 4-2
(N) and R (n) are added, and the result is L
(N) + R (n) is output. That is, the adder 4-2 constitutes the sum signal generating means. The output from the adder 4-2 is branched into two, and the convolution processing means 13-
3, 13-4, and the convolution processing means 13-3,
In 13-4, convolution processing is performed on L (n) + R (n), and the results are input to adders 4-5 and 4-6, respectively.

On the other hand, in the multiplier 3-1, R (n) is multiplied by -1, and the result, -R (n), is input to the adder 4-1, and in the adder 4-1, L (n). ) And -R (n) are added and the result L (n) -R (n) is output. That is, the multiplier 3-1 and the adder 4-1 form difference signal extraction means. The output from the adder 4-1 is branched into two, and convolution processing means 13-1 and 13-, respectively.
2, and the convolution processing means 13-1 and 13-2 respectively perform convolution processing on L (n) -R (n), and the results are input to adders 4-5 and 4-6, respectively. . In the adder 4-5, the convolution processing means 13-3, 1
The output from 3-1 is added, and the result is branched into two, one to adder 4-7 and the other to adder 4-
8 is input. In the adder 4-6, the convolution processing means 1
The outputs from 3-4 and 13-2 are added, the result is branched into two, and one is input to the multiplier 8-1 and the other is input to the adder 4-8. Adder 4 in multiplier 8-1
Multiply the output from -6 by -1 and add the result to adder 4-
Type in 7.

In the adder 4-7, L (n) and the adder 4-
The output from 5 and the output from the multiplier 8-1 are added,
The result is input to the D / A converter 14-1. In the adder 4-8, R (n), the output from the adder 4-6, and the output from the adder 4-5 are added, and the result is input to the D / A converter 14-2. D / A converters 14-1 and 14
At -2, the outputs from the adders 4-7 and 4-8 are converted from digital signals into analog signals, and the results are output from the output terminals 10 and 11, respectively. That is,
The outputs from the convolution processing means 13-3 and 13-1 are output in phase from the output terminals 10 and 11, while the outputs from the convolution processing means 13-4 and 13-2 are output terminals 10 and 1.
Output from 1 in reverse phase. The output signal is reproduced from a speaker or the like.

As described above, the difference signal and the sum signal of the stereo signals are separately convoluted into those reproduced in the same phase and those reproduced in the opposite phase, so that the sense of spread due to the opposite phase reproduction is provided. The uncomfortable sense of reverse phase can be softened by adding the signal obtained and reproduced in phase.

In this embodiment, adders 4-5, 4-
There is no multiplier for adjusting the mix balance when performing the addition at 6, but the convolution processing means 13-1 and 13
-2, 13-3, 13-4 and adders 4-5, 4-6 are respectively provided with multipliers, or adders 4-1 and 4
-2, a multiplier is provided after the convolution processing means 1
The mix balance of the outputs from 3-1, 13-2, 13-3, 13-4 may be adjusted.

Also, in this embodiment, adders 4-7, 4-
Although there is no multiplier for adjusting the mix balance when performing the addition in 8, the convolution processing means 13-1, 13-is provided by providing a multiplier after the adders 4-5, 4-6.
Output from 2, 13-3, 13-4 and L (n), R
It may be possible to adjust the mix balance with (n).

[0030]

As described above, according to the present invention, the reflected sound is separately convoluted into the sum signal and the difference signal of the stereo signal,
It can reproduce a natural sound field with a sense of antiphase and a realistic sound field, and convolves the reflected sound into the sum signal, so it is also suitable for adding the initial reflected sound. Further, since two convolution processing means are provided for each of the sum signal and the difference signal of the stereo signal, a sound field in which the reflected sound convolved by the signals output from the two output terminals is different is reproduced. It is possible to add reflected sound in stereo.

Furthermore, by changing the delay amount of the delay device and the coefficient of the multiplier inside the convolution processing means, it is possible to generate a plurality of types of sound fields, such as a sound field with rich resonance and a sound field with few reflected sounds. Since the reflected sound can be convolved by taking advantage of the characteristics of the sum signal and the difference signal of the stereo signal, it is possible to reproduce a wider variety of sound fields.

Further, the difference signal and the sum signal of the stereo signals are separately convoluted into those reproduced in the same phase and those reproduced in the opposite phase, so that a sense of spread due to the opposite phase reproduction can be obtained. In addition, the uncomfortable feeling of the opposite phase can be softened by adding the signal to be reproduced in the same phase.

[Brief description of drawings]

FIG. 1 is a hardware block diagram of a sound field signal reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a hardware block diagram of convolution processing means according to the present embodiment.

FIG. 3 is a hardware block diagram of a sound field signal reproducing device according to a second embodiment of the present invention.

FIG. 4 is a hardware block diagram showing a configuration of a conventional sound field signal reproducing device.

[Explanation of symbols]

1, 2, 15 Input terminals 3, 3-1, 8, 8-1, 6, 17-1, 17-2, 1
7-3, ..., 17-m Multipliers 4, 4-1, 4-2, 4-3, 4-4, 4-5, 4-
6, 4-7, 4-8, 4-9, 4-10, 7, 9, 18
Adder 5, 16-1, 16-2, 16-3, ..., 16-m
Delay device 10, 11, 19 Output terminal 12-1, 12-2 A / D converter 13-1, 13-2, 13-3, 13-4 Convolution processing means 14-1, 14-2 D / A conversion vessel

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryo Tagami 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Mikio Oda 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. Input means for inputting a stereo signal, difference signal extracting means for extracting a difference signal between the L channel signal and the R channel signal of the input stereo signal, and the L channel of the input stereo signal. Signal generating means for generating a sum signal of the signal and the R channel signal, difference signal branching means for branching the extracted difference signal into at least two signals, and at least two generated sum signals.
Sum signal branching means for branching into one signal, at least two difference signal convolution processing means for performing convolution processing on each of the divided difference signals, and at least two sum signals for performing convolution processing on each of the generated sum signals Convolution processing means, at least two addition means for adding the processing result of the difference signal convolution processing means and the processing result of the sum signal convolution processing means, and at least two output means for outputting the addition result of the addition means. Device for reproducing sound field signal. 2. The at least two adding means is means for adding a stereo signal of a sum signal and a difference signal of both signals to the L channel signal or the R channel signal. Sound field signal reproduction device. 3. Input means for inputting a stereo signal, difference signal extracting means for extracting a difference signal between the L channel signal and the R channel signal of the input stereo signal, and the L channel of the input stereo signal. Signal generating means for generating a sum signal of the signal and the R channel signal, difference signal branching means for branching the extracted difference signal into two signals, and branching the generated sum signal into two signals. Sum signal branching means, two difference signal convolution processing means for performing convolution processing on each of the branched difference signals, two sum signal convolution processing means for performing convolution processing on each of the generated sum signals, and the difference Two adding means for adding the processing result of the signal convolution processing means and the processing result of the sum signal convolution processing means, and outputs from the two adding means, respectively. And two branch means for branching into two,
Two signal adding means for adding an output signal from one branching means of the two branching means and an output signal from the other branching means, and an addition result of each of the two signal adding means are output. And two output means,
A sound field signal reproducing apparatus, wherein one of the two signal adding means performs addition after multiplying one signal of the two signals input to the signal adding means by -1. 4. The two signal adding means are further each L
4. The sound field signal reproducing apparatus according to claim 3, wherein the channel signal and the R channel signal are added together.