JPH0728482A - Acoustic effect control device - Google Patents

Abstract

PURPOSE:To simply and freely change the spread of reproduced sound field only while keeping the quality of the reproduced sound constant in an acoustic effect control device which artifically generates and adds reverberation. CONSTITUTION:The device consists of an initial reflected sound generation means 1 which generates an initial reflected sound, a second reverberation sound generating means 2 which generates a second reverberation sound that follows the initial reflected sound, an adding means 3, which adds the outputs of the means 1 and 2 into input signals, and a sound field control means 4 which variably controls respective circuit coefficients tau1 to tau6 and r of the means 1 and 2 by using a room size k of the reproduced sound field as a parameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound effect control device for artificially generating reverberation and adding the reverberation. The present invention relates to a sound effect control device that can be freely changed.

[0002]

2. Description of the Related Art Sounds heard in a concert hall include not only direct sounds but also indirect sounds complicatedly reflected by surrounding walls. FIG. 11 shows a reverberation pattern of sound in a concert hall or the like. In this reverberation pattern, ER is the initial reflected sound that is primarily reflected from the surrounding walls, and REV is a high temporal density that is caused by repeating the initial reflected sound ER many times and has a long duration. It is a long late reverberation. The reverberation time T is represented by the time it takes for the original sound to decay to -60 dB.

As is apparent from FIG. 11, the reverberation is composed of an early reflection sound ER and a subsequent late reverberation sound REV. Therefore, when reproducing music with a stereo device or the like, the early reflection sound ER and the late reverberation sound R as shown in FIG.
By artificially generating the EV and adding them to the original sound, it is possible to reproduce a sound having the same sound as in a concert hall.

FIG. 12 shows an example of a conventional acoustic effect control device for artificially generating and adding the above-mentioned reverberation.
In the figure, reference numeral 81 denotes an initial reflected sound E from the input signal (original sound).
An early reflection sound generator for generating R, 82 a late reverberation sound generator for generating a late reverberation sound REV from an input signal, and 83 an early reflection sound signal ER (made by the early reflection sound generator 81. The same sign as the initial reflected sound) and the late reverberation sound signal REV (which uses the same sign as the late reverberation sound) generated by the late reverberation sound generator 82 are added to the input signal (original sound) and shown in FIG. It is an adder that obtains an output signal having such a predetermined reverberation pattern.

In general, the early reflection sound generator 81 is used.
Is a known digital filter using convolution, and the late reverberation generator 82 is an all-pass filter combining a delay circuit, an adder and a multiplier.

[0006]

By the way, the initial reflected sound generator 81 and the late reverberation sound generator 82 have an initial reflected sound ER and a late reverberation sound REV each having an arbitrary pattern by changing their circuit coefficients. Can be generated. Therefore, the combination of the early reflection sound ER and the late reverberation sound REV can be considered infinitely, and it requires a fairly high degree of specialized knowledge and training to obtain the desired reverberation characteristics of the reproduced sound field, and it is considerably handled by an amateur. There was a problem that it was difficult.

Further, as described above, the fact that the relationship between the early reflected sound ER and the late reverberant sound REV changes randomly means that the quality of the reproduced sound changes, which means that the reproduced sound field currently realized. Is that it will change to something else. Therefore, when the early reflection sound ER and the late reverberation sound REV can be freely changed as in the conventional sound effect control device, the amateur does not have a clear reference for the reverberation effect, so It was not possible to easily change only the width of the reproduced sound field that was realized, for example, from a small hall to a large hall, while maintaining the same quality of sound.

The present invention has been made in order to solve the above problems, and an object of the present invention is to make it possible to simply and freely adjust the width of a reproduced sound field while maintaining the same quality of the reproduced sound. An object of the present invention is to provide a sound effect control device that can be changed.

[0009]

In order to solve the above-mentioned problems, an acoustic effect control device according to the invention generates an initial reflected sound generating means for generating an initial reflected sound and a late reverberant sound following the initial reflected sound. Late reverberant sound generating means, adding means for adding the output of the early reflected sound generating means and the output of the late reverberant sound generating means to the input signal, and the early reflected sound generating means and the late reverberant sound generating means, respectively. Sound field control means for variably controlling the circuit coefficient of (1) with the room size of the reproduced sound field as a parameter.

[0010]

When the room size is designated from the operation panel or the like, the sound field control means sets the circuit coefficients of the early reflection sound generation means and the late reverberation sound generation means to values corresponding to the room size. As a result, the early reflected sound generating means and the late reverberant sound producing means respectively generate an early reflected sound signal and a late reflected sound signal corresponding to the designated room size.
Then, the adder adds the generated initial reflected sound signal and reverberation sound signal to the input signal (original sound) and outputs the added signal.

As described above, in the case of the present invention, the circuit coefficient of each of the early reflection sound generation means and the late reverberation sound generation means is set with the room size as a parameter. Therefore, the early reflected sound and the late reverberant sound are always generated with a constant relationship with the room size as a parameter. Therefore, it is possible to freely change only the width of the reproduced sound field from a small hall to a large hall while maintaining the same quality of reproduced sound.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention, in which an early reflection sound generator 1, a late reverberation sound generator 2, an adder 3, a control unit 4 including a microcomputer, a delay time storage unit, etc. It is composed of a ROM 5, an operation panel 6, and a display 7. In this embodiment, as will be described later, with the room size k as a parameter, delay times τ _{1 to} τ ₅ which are circuit coefficients of the initial reflected sound generator 1, and
This is an example of a case where the delay time τ ₆ which is the circuit coefficient of the late reverberation sound generator 2 is variably controlled.

The block portion 10 surrounded by a dotted line in FIG. 1 is actually a circuit realized by software using a digital signal processor (DSP), but for the sake of clarity of explanation. 2 shows the circuit functions realized by the DSP as hardware.

Early reflection sound generator 1 in the above embodiment
Is, for example, each consisting of a delay time τ ₁ ~τ _{5 5}
One of the delay circuits 11 ₁ to 11 ₅ are cascaded, the multiplier 12 ₁ to 12 ₅ which each delayed output of the five delay circuits 11 ₁ to 11 ₅ which is the cascade having a predetermined multiplication coefficient g ₁ to g ₅
And is sent to the adder 3. The circuit including the delay circuits 11 _{1 to} 11 ₅ , the multipliers 12 _{1 to} 12 ₅ and the adder 3 constitutes a non-cyclic digital filter using so-called convolution integral, and its output characteristic is shown in FIG. It becomes something like.

The reverberation sound generator 2 has adders 22 and 23 connected to the input and output ends of a delay circuit 21 having a delay time τ ₆ ,
While feed-forwarding the input signal (original sound) to the adder 23 through the multiplier 25 composed of the attenuation coefficient −r,
The addition output of the adder 23 is multiplied by the attenuation coefficient r to obtain a multiplier 24.
It is configured to feed back to the adder 22 through. These delay circuit 21, adders 22 and 23
The circuit composed of and the multipliers 24 and 25 constitutes a known all-pass filter, and its output characteristic is as shown in FIG. Note that in FIG. 3, the interval of τ ₆ is shown enlarged for easy understanding of the description. In practice, the interval of tau ₆ is a value smaller than τ ₁ ~τ ₅ in FIG. 2, tau ₁ ~
A waveform that is deeper than τ ₅ has a slope of 1 / r and continues for a long time.

The delay time storage ROM 5 is shown in FIG.
As illustrated in (B), the delay time table for the early reflection sound
And the delay time table for late reverberation sound are stored.
The delay time table for initial reflected sound in FIG.
Each delay circuit 11 of the reflected sound generator 1₁~ 11_FiveSlow for
Total time τ₁~ Τ_FiveThe specific value of
A plurality of “z k” are stored as parameters. Also, the figure
In the delay time table for late reverberation sound of 4 (B),
Delay time τ for the delay circuit 21 of the sound generator 2 ₆Ingredient
The physical value is the room size k of the reproduced sound field as a parameter.
Are stored multiple times.

The reason for using the table shown in FIGS. 4A and 4B will be described below. Now, the reverberation time T of a room whose one side is L [m] as shown in FIG. 5A is given by the following equation by the well-known Sabine equation. T = (4V / cαS) × [ln 10 ⁶ ] [second] V: Total volume of room c: Sound velocity α: Average sound absorption rate S: Total surface area of room ln: Natural logarithm

[0018] Now, the dimension of each side of the room is k times as in FIG. 5 (D), the total volume V of the room and '= k ³ · V, the total surface area S of the room' = k ² · S Therefore, the reverberation time T ′ of the room in (D) is T ′ = (4V ′ / cαS ′) × [ln 10 ⁶ ] = (4 · k ³ · V / cαk ² · S) × [ln 10 ⁶ ] = K (4V ′ / cαS ′) × [ln 10 ⁶ ] = kT, and it can be seen that the reverberation time increases / decreases in proportion to the room size k.

The meaning of the above equation will be explained with reference to FIG. 5. The characteristic of the early reflection sound ER in a room having a size as shown in (A) is (B), and the characteristic of the late reverberation sound REV is (C). )
Then, the characteristic of the early reflection sound ER of the room of the size (D) whose one side is multiplied by k becomes like (E), and the characteristic of the late reverberation sound REV becomes like (F). And each time is equal to Δt and T multiplied by k.

That is, when the above results are applied to the circuit coefficients of the early reflection sound generator 1 and the late reverberation sound generator 2 of FIG. 1, the initial reflection sound is obtained in order to obtain the characteristics of FIGS. 5B to 5E. Each delay time τ _{1 to} τ ₅ of the generator 1 may be multiplied by k, and in order to obtain the characteristics of FIGS. 5C to 5F, the delay of the late reverberation sound generator 2 in FIG. the time τ ₆ 6
As shown in FIG. 7, or the delay time τ as shown in FIG.
_The attenuation coefficient r may be changed to r'according to the room size k while leaving _{6 as it} is. 6 and 7, the interval of τ ₆ is also shown enlarged in the same manner as in FIG. 3 described above.

When the attenuation coefficient r is changed as shown in FIG. 7, τ ₆ is not multiplied by k, so that the density of the reverberation sound component is slightly different from that in the case of FIG. Is almost unaffected by the magnitude of the reverberation time, and is almost determined by the length of the reverberation time T. Therefore, almost the same result can be obtained by changing either the delay time τ ₆ or the attenuation coefficient r.

As is clear from the above results, the delay times τ _{1 to} τ ₅ of the early reflection sound generator 1 and the late reverberation sound generator 2 are large.
If the delay time τ ₆ or the attenuation coefficient r is changed according to the room size k, for example, only the size of the concert hall as the reproduction sound field is maintained while maintaining the quality of the sound as a concert hall. It shows that you can freely change from a small hall to a large hall.

The present invention has been made by utilizing the above relationship. In the case of the embodiment shown in FIG. 1, the delay times τ _{1 to} τ ₅ of the early reflected sound generator 1 and the late reflected sound generator 2 are delayed. Delay time τ
₆ and ₆ are variably controlled according to the room size k. As will be described later, the delay time storage ROM 5
Each delay time τ corresponding to the room size k specified from
By reading _{1 to} τ ₆ and setting them in the delay circuits of the early reflected sound generator 1 and the late reflected sound generator 2,
It is possible to freely change only the width of the reproduced sound field without changing the quality of the reproduced sound.

The delay time storage ROM 5 stores not only one kind of delay time table for a concert hall or the like, but also delay time tables corresponding to other various reproduced sound fields, such as live houses and churches. It is desirable to store a delay time table corresponding to a theater or the like. This makes it possible to generate and add reverberation of a desired reproduction sound field such as a concert hall, a live house, a church, and a theater.

In order to obtain the reverberation of the various reproduced sound fields, it is necessary to prepare the multiplication coefficients g _{1 to} g ₅ and the attenuation coefficient r corresponding to each reproduced sound field in the ROM 8 or the like in advance.
Each multiplier 12 ₁ to 12 ₅ reads the multiplication coefficient g ₁ to g ₅ and r corresponding to the designated reproduction sound field, 24, 25
The initial reflected sound generator 1
Then, the late reverberation sound generator 2 can generate the early reflection sound ER and the late reverberation sound REV corresponding to the reverberation characteristics of the designated reproduction sound field.

The operation panel 6 increases / decreases a reproduction sound field designating key 61 for selecting and designing a desired reproduction sound field of a concert hall, a live house, a church, a theater, etc., and a size of the reproduction sound field, that is, a room size k. Up for (UP)
A key 61, a DOWN key 62, and other necessary keys are provided.

Next, the operation of the embodiment having the above configuration will be described with reference to the flowchart of FIG. First,
The reproduction sound field designation key 61 is operated to select a desired reproduction sound field (step S1). Assuming that the concert hall is selected as the reproduction sound field, the control unit 4 controls the RO
Multiplication coefficients g _{1 to} g ₅ for obtaining the reverberation characteristic of the concert hall designated from M8. Read the damping coefficient r,
These coefficients are used as the early reflection sound generator 1 and the late reverberation sound generator 2.
To the multipliers 12 _{1 to} 12 ₅ and 24 and 25. Thereby, the early reflection sound generator 1 and the late reverberation sound generator 2 generate the early reflection sound ER and the late reverberation sound REV of the concert hall. When this reproduced sound field is designated, the control unit 4 is set so as to access only each delay time table (for example, FIG. 4) for the concert hall stored in the delay time storage ROM 5 thereafter.

Then, in order to set the size of the concert hall to be reproduced, the up key 62 or the down key 6
When 3 is operated, the room size k is set as follows. That is, assuming that the up key 62 has been operated, this is determined in step S3, and the process proceeds to step S4. Then, in step S4, it is determined whether or not the current set room size k of the initial reflected sound ER is the maximum value n, and if it is the maximum value n, the process proceeds to step S5 and the display 7 is displayed. A warning is displayed that the room size k cannot be increased any further.

In step S4, the initial reflected sound E
When it is determined that the current set room size k of R is less than or equal to the maximum value n, the process proceeds to step S6, and it is determined whether or not the current set room size k of the late reverberation REV is the maximum value n. Is determined, and if the maximum value is n, the process proceeds to step S5, and the display 7
A warning is displayed that the room size k cannot be increased any more.

In step S6, the late reverberation R
When it is determined that the current set room size k of the EV is less than or equal to the maximum value n, the processing is determined to be possible, the process proceeds to step S7, the number of touches of the up key 62 is counted, and the room size k is set by the counted number. Increase. For example,
If the current room size k is set to 3 and the up key 62 is touched twice, the new set room size k becomes 5. The setting status of the room size k is displayed on the display 7 and can be confirmed in real time.

When the room size k = 5 is specified as described above, the control unit 4 proceeds to step S7 in FIG.
Access the initial reflected sound delay time address position of the table of room size k = 5 in (A), reads the delay time of the address position ^{_{k 4 t 1 ~k 4 t 5}} , further
In step S8, the address position of the room size k = 5 in the delay time table for late reverberation sound in FIG. 4B is accessed, and the delay time k ⁴ t ₆ at the address position is read.

Then, in step S9, as shown in FIG.
Each read from the table in (A) the value k ⁴ t ₁ ~k ⁴ t
₅ is sent to the initial reflected sound generator 1, and delay circuits 11 _{1 to} 11
_The value k ⁴ t read from the table of FIG. 4B is set as the values of the delay times τ _{1 to} τ ₅ of FIG.
₆ is sent to the late reverberation sound generator 2 and set as the value of the delay time τ ₆ of the delay circuit 21.

When the delay times τ _{1 to} τ ₆ are set in the respective delay circuits as described above, the early reflection sound generator 1 and the late reverberation sound generator 2 are given with the room size k = 5. It generates and outputs an early reflection sound signal ER and a late reverberation sound signal REV corresponding to a concert hall of a room size.

On the other hand, if the down key 63 is operated in step S3, the process proceeds to step S1.
Move to 0. Then, in step S10, it is determined whether or not the current set room size k of the initial reflected sound ER is the minimum value 1, and when it is the minimum value 1, the process proceeds to step S5 and the display 7 is displayed. A warning is displayed that the room size k cannot be reduced any further.

If it is determined in step S10 that the currently set room size k of the initial reflected sound ER is equal to or greater than the minimum value 1, the process proceeds to step S11, and the currently set room size of the late reverberation sound REV is set. It is determined whether or not k is the minimum value 1, and when it is the minimum value 1, the process proceeds to step S5, and similarly to the above, a warning message is displayed on the display 7 that the room size k cannot be further reduced. To do.

If it is determined in step S11 that the currently set room size k of the late reverberation sound REV is equal to or larger than the minimum value 1, it is determined that processing is possible, the process proceeds to step S12, and the down key 63 is touched. The number of times is counted, and the room size k is reduced by the count value. For example, if the current room size k is set to 3 and the down key 63 is touched twice, the new set room size k becomes 1.

When the room size k = 1 is designated as described above, the control unit 4 determines in step S12 the address position of the room size k = 1 in the delay time table for initial reflected sound of FIG. 4 (A). To read the delay times t _{1 to} t ₅ of the address position, and further, in step S13, access the address position of the room size k = 1 in the delay time table for late reverberation sound of FIG. 4B. , The delay time t ₆ at the address position is read.

Then, in step S9, as shown in FIG.
The values t ₁ ~t ₅ read from the table (A) feeding an initial reflected sound generator 1, and sets the value of the delay circuits 11 ₁ to 11 ₅ the delay times tau ₁ ～Tau ₅ of FIG The value t ₆ read from the table of FIG. 4 (B) is sent to the late reverberation sound generator 2 and set as the value of the delay time τ ₆ of the delay circuit 21.

When the respective delay times τ _{1 to} τ ₆ are set as described above, the early reflection sound generator 1 and the late reverberation sound generator 2 operate in a room given the set room size k = 1. Generates and outputs an early reflection sound signal ER and a late reverberation sound signal REV corresponding to a concert hall having a size of.

As a result of controlling as described above, the size of the concert hall can be freely changed from a small hall to a large hall for reproduction while keeping the quality of the reproduced sound as a designated concert hall constant. Will be able to.

In the above-mentioned embodiment, each time the room size k is increased or decreased, the delay times τ _{1 to} τ ₆ at the corresponding room size position are read out. For example, as shown in FIGS. 9 and 10. Is the position when the room size k = 1, the position when the room size k = 2, the position when the room size k = 3, and the position when the room size k = 4. If it is read diagonally every other position, the previous value can be used as it is for one of τ _{1 to} τ ₅ or τ ₆ at each read position of ,,,, ... It can be reduced.

In the above case, τ _{1 to} τ ₅ or τ ₆ deviates from the originally set ratio of the room size k, but normally, the rate of increase in one step of the room size k is extremely large. Therefore, it is considered that there is not much difference in the values of τ ₁ to τ ₅ or τ ₆ between the adjacent room sizes. Therefore, even when the reading is performed obliquely as described above, the sound of the reproduced sound is not so affected.

Further, it is not always necessary to provide all of the delay times τ _{1 to} τ ₆ corresponding to the room sizes k = 1 to n in the table format, for example, the standard room size k = 1. Only the delay times τ _{1 to} τ _{6 at the} time of are prepared, and each room size k = 2 from this reference value.
The delay times τ _{1 to} τ ₆ in the case of up to n may be calculated.

In the above embodiment, the pattern of the late reverberation sound REV is changed by the delay time τ ₆ of the delay circuit 21, but as described above, the pattern of the late reverberation sound REV is the multiplier. It can also be realized by changing the damping coefficient r of 24 and 25. Therefore, instead of the delay time τ ₆ table of FIG. 4B, the attenuation coefficient r is prepared as a table, and the attenuation coefficient r corresponding to the designated room size k is read out, whereby the attenuation of the multipliers 24, 25 is reduced. The coefficient r may be changed.

[0045]

As described above, according to the sound effect control apparatus of the present invention, each of the circuit coefficients of the early reflection sound generator and the late reverberation sound generator is variable with the room size of the reproduced sound field as a parameter. Since the control is performed, it is possible to easily and freely change only the width of the reproduced sound field while maintaining the same quality of reproduced sound.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a sound effect control device according to the present invention.

FIG. 2 is an explanatory diagram of an initial reflected sound.

FIG. 3 is an explanatory diagram of a late reverberation sound pattern.

FIG. 4 is a diagram showing an example of a delay time table for early reflection sound and a delay table for late reverberation sound used in the present invention.

FIG. 5 is an explanatory diagram of changes in the early reflection sound and the late reverberation sound with respect to the size of the room.

FIG. 6 is a diagram showing reverberation sound patterns when the delay time is changed.

FIG. 7 is a diagram showing a reverberation sound pattern when an attenuation coefficient is changed.

FIG. 8 is a flowchart of the operation of the embodiment.

FIG. 9 is a second method of reading the delay time from the table.
It is a figure which shows the example of.

FIG. 10 is a diagram showing a third example of a method of reading delay time from a table.

FIG. 11 is a block diagram showing a conventional example of a sound effect control device.

FIG. 12 is a reverberation characteristic diagram of a conventional example.

[Explanation of symbols]

1 Early Reflection Sound Generator 2 Late Reverberation Sound Generator 3 Adder 4 Control Unit 5 Delay Time Storage ROM 6 Operation Panel 7 Display 8 ROM 9 RAM 10 DSP 11 _{1 to} 11 ₅ Delay Circuit 12 _{1 to} 12 ₅ Multiplier 21 Delay circuit 22,23 Adder 24,25 Multiplier 61 Play sound field designation key 62 Up key 63 Down key ER Early reflection sound (initial reflection sound signal) REV Late reverberation sound (late reverberation signal) τ _{1 to} τ ₅ delay Time τ ₆ Delay time r Attenuation coefficient

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location H03H 17/02 G 8842-5J 21/00 8842-5J H04R 3/00 310 H04S 1/00 D 8421 -5H 9381-5H G10K 15/00 B (72) Inventor Masayuki Kato 25 Nishimachi, Yamada, Kawagoe, Saitama Prefecture 1 Kawaguchi factory, Pioneer Co., Ltd. (72) Shuichi Mori Nishida, Yamago, Kawagoe, Saitama Address 25 Pioneer Corporation Kawagoe Factory

Claims (1)

[Claims] 1. An initial reflected sound generating means for generating an initial reflected sound, a late reverberation sound generating means for generating a late reverberation sound following the initial reflected sound, an output of the initial reflected sound generation means and the latter reverberation sound. An adding means for adding the output of the generating means to the input signal, and a sound field control means for variably controlling the circuit coefficients of the initial reflected sound generating means and the late reverberation sound generating means with the room size of the reproduced sound field as a parameter. A sound effect control device comprising: