JPH0736474A - Automatic adjusting device for echo sound - Google Patents

Abstract

PURPOSE:To provide the automatic echo sound adjusting device which can set an echo sound to be added to a sound signal to an optimum state corresponding to a musical performance hall. CONSTITUTION:The test signal outputted from a test signal output circuit 34 and a test reflected signal which is an electric signal of the echo sound of a test sound obtained by outputting the test signal from a speaker 30 are inputted to a control means 32. The control means 32 outputs an echo amount control signal and an echo time control signal based on those test signal and test reflected signal. With the control signals, an echo quantity adjusting circuit 36 and an echo time adjusting circuit 38 set the echo quantity and echo time of the echo sound to be added to the sound signal. Therefore, the optimum echo sound matched with echo characteristics of the musical performance hall can be added to the sound signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reverberant sound added to an audio signal, and more particularly to automatic adjustment thereof.

[0002]

2. Description of the Related Art In a performance hall such as a hall, the reverberation (acoustic characteristics) of the played voice (original sound) is important. The acoustic characteristics are determined by the size of the performance hall, the height of the ceiling, and the structural material and soundproof material of the ceiling and wall surfaces. Furthermore, it depends on the number of listeners.

One of the acoustic characteristics is an echo characteristic which is a characteristic of an echo sound (echo and reverb) that arrives at a listener after the original sound is reflected by a wall surface or the like and is delayed from the original sound. Since it is not desirable to generate echoes and reverbs in a performance hall, the echoes and reverbs are designed so as not to occur as much as possible (the degree of reverberation is low), but it is difficult to completely set them to zero.

Here, the echo means that the generated original sound is reflected by a wall surface or the like and a first wave whose time is delayed from the original sound reaches the listener, and is further reflected by another wall surface or the like and is delayed by a second wave. Reverberation that reaches the listener one after another with a time interval, such as a wave, and a third wave with a further time delay. On the other hand, reverb is a reverberant sound in which a reflected wave reaches the listener continuously without a time interval unlike the echo.

However, when playing a song,
Conversely, this echo or reverb may be used to enhance the acoustic effect of the song.

In this case, the voice signal obtained by converting the voice into an electric signal by the microphone is added with an echo or reverb obtained by electrically processing the voice signal as follows.

The echo delays the voice signal for a required time (reverberation time) and produces a delayed first wave whose amplitude (reverberation amount) is slightly reduced from that of the voice signal. The second wave which is further reduced is created, and similarly, the third wave, the fourth wave, the fifth wave, ... (Number of echoes) are created and added to the audio signal. The reverb is created by inserting 10 or more delayed waves, that is, several tens of waves between the echoes. Thus, the echo or reverb is added to the audio signal by setting the echo echo amount, echo time, and echo count. When making this setting, it is necessary to consider the reverberation characteristics of the performance venue. That is, if the performance hall is a hall that easily absorbs voice (low degree of reverberation), a large echo is applied to the voice signal. On the other hand, in a hall where sound is difficult to be absorbed (the degree of reverberation is high), even if the echo is small, the echo in the hall causes a large echo as a whole.

Conventionally, the reverberant sound of the audio signal is adjusted according to the performance hall.

[0009]

However, the conventional device as described above has the following problems.

When setting the echo or reverb echo amount, echo time, or echo frequency at the performance hall, the coordinator actually listens to the voice and its echo or reverb repeatedly to listen to it, and adjust it according to the performance hall. There was a problem that it had to be adjusted and was complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide an echo sound automatic adjusting device capable of optimally setting the echo sound added to a sound signal according to a performance hall. To do.

[0012]

According to a first aspect of the present invention, there is provided a reverberation sound automatic adjustment device, which includes a microphone for inputting a voice and converting the voice into an electric signal, an amplifier for amplifying the voice signal input from the microphone, and a voice signal. The reverberation amount of the reverberation sound added to the, the reverberation amount adjustment circuit that adjusts based on the reverberation amount control signal, the reverberation time adjustment circuit that adjusts the reverberation time of the reverberation sound added to the audio signal based on the reverberation time control signal,
A reverberation automatic adjustment device comprising a speaker that outputs a voice signal as a voice, the test signal output circuit being provided in a predetermined portion of the device and outputting a predetermined test signal,
At the same time as inputting the test signal, the test signal is output as a test sound from the speaker, is reflected by the reflection surface, is input to the microphone, and is input to the microphone as a test reflection signal. Based on this, output the echo amount control signal to the echo amount adjustment circuit,
A control means for outputting an echo time control signal to the echo duration adjustment circuit is provided.

[0013]

In the automatic echo sound adjusting device according to claim 1, the test signal is added to the voice signal based on the test signal and the test reflection signal which is the electric signal of the echo sound of the test sound output from the speaker. The reverberation amount and the reverberation time of the reverberation sound are set. Therefore, the optimum reverberant sound can be automatically added to the audio signal according to the reverberant characteristic of the performance hall.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the basic configuration of an echo sound automatic adjustment apparatus 3 according to an embodiment of the present invention. The device 3 includes a microphone 20 for inputting voice and converting it into a voice signal, and an amplifier 2 for amplifying a voice signal input from the microphone 20.
2, an echo amount adjusting circuit 36 for adjusting the echo amount of the echo sound added to the audio signal, an echo time adjusting circuit 38 for adjusting the echo time of the echo sound added to the audio signal, a speaker 30 for outputting the audio signal, a microphone 20 A test signal output circuit 34 and a control means 32 provided between the amplifier 22 and the amplifier 22.

The test signal output from the test signal output circuit 34 and the test reflection signal which is an electric signal of the echo sound of the test sound output from the speaker 30 are input to the control means 32. The control means 32 outputs an echo amount control signal to the echo amount adjusting circuit 36 and an echo time control signal to the echo duration adjusting circuit 38 based on the test signal and the test reflection signal. The echo amount adjusting circuit 36 sets the echo amount of the echo sound added to the audio signal by the echo amount control signal. Further, the echo duration adjustment circuit 38 sets the echo time of the echo sound added to the audio signal by the echo time control signal.

FIG. 2 shows a block diagram of an automatic reverberation sound adjusting device 3 which is constructed by concrete hardware of FIG. This device 3 includes a microphone 20, a head amplifier / microphone amplifier 24, a microphone volume 21, a microphone tone 23, and a mixer.
26, power amplifier 28, speaker 30, test signal output circuit
34, an echo volume 36 which is an echo amount adjusting circuit and its drive motor 40, an echo / reverb delay volume 38 which is an echo time adjusting circuit and its drive motor 42, and a control circuit 32. A block diagram of the control circuit 32 is shown in FIG. 4 and 5 are time charts showing the operation of the device 3. In this embodiment, the number of echo or reverb echoes added to the audio signal is fixed to about 5 to 7.

First, when this device 3 adds a reverberation (echo, reverb) signal to a voice signal and reproduces it,
Operation to adjust the echo amount of the echo signal (echo amount control signal E
The output of VC) will be described.

In FIG. 2, the test signal is output by the test signal output circuit 34. For this test signal, for example, a tone burst wave of about 10 sine waves of 3 KHz is used. The echo function of the device 3 is stopped during the operation of measuring the echo amount and echo time of the echo signal of the test signal.

When the start SW is pushed and turned on,
The start signal S is generated (FIG. 4a), and the test signal output circuit 34 outputs the test signal T ₁ after a delay of t1 from the start signal S (FIG. 4b). The test signal T ₁ is the head amplifier / microphone amplifier 24, the power amplifier 2
It is amplified via 8 and output from the speaker 30 as a test sound TO. The microphone 20 has this test sound TO
Then, the echo sound EO (the echo first wave sound, the echo second wave sound, ...) In which the test sound TO is reflected on the ceiling or the wall of the performance hall is also input. As shown in FIG. 4c, the test tone T is input to the microphone 20 and converted into an electrical signal, and the test signal T ₂ is generated from the generation of the test signal T ₁ by t2.
Then, an echo signal E (echo first wave signal E ₁ , echo second wave signal E ₂ , ...) In which the echo sound EO is similarly converted into an electric signal is input. In this example, the echo first wave signal E ₁ , the echo second wave signal E ₂ , ... Are called test reflection signals.

The test signal T ₂ is given to the control circuit 32. In FIG. 3, the test signal T ₂ is the rectification / integration circuit 4
The signal is rectified and integrated by 4 to form a signal K (FIG. 4d), and the waveform is shaped by the waveform shaper 46 into a signal G (FIG. 4e).

The signal obtained by inverting the signal G by the inverter 48 (FIG. 4h) is given to the toggle FF 50 (FIG. 4i),
Further, the output is inverted by the inverter 52 (see FIG.
j) Toggle is given to FF54.

This output signal N (FIG. 4k) is the echo first
It is a signal that becomes "L" when the wave signal E ₁ is generated. When this becomes "L", it is used as a stop signal for stopping the calculation of the CPU 72.

The signal N and the signal P (FIG. 4n) obtained by integrating the start signal S by the integrator 60 (FIG. 4m) into a square wave by the waveform shaper 62 are given to the AND 56. This output is given to the AND 66 together with the start signal S, and its output becomes the start / stop signal SS. The start / stop signal SS is given to the CPU 72, ANDs 68, 70 and the slope signal generator 80.

On the other hand, the signal K is converted to A / D by the A / D converter 64.
D converted, and the output signal H (FIG. 4r) is the same as AN
D68, 70 and slope signal generator 80. However, the sampling frequency of the A / D converter 64 is the CPU
It is kept low considering the calculation speed of 72.

Further, the signal G is given to the toggle FF78. This output signal I (FIG. 4f) is given to AND68,
The inverted signal J (FIG. 4g) of the output signal is given to the AND 70. Start / stop signal SS, signal H, signal I is A
Given the ND68, the output signal DT ₂ obtained by extracting only the digital signal of the test signal T ₂ is taken out (Fig. 5
a), input to the CPU 72, and stored in the RAM 94 built in the CPU 72.

When the start / stop signal SS, the signal H, and the signal J are given to the AND 70, the echo first wave E
_The signal DE _{1 obtained} by extracting the digital signal of ₁ is taken out (FIG. 5b), is also input to the CPU 72 and is stored in the RAM 94.

FIG. 6 shows the digital signal DT ₂ (output value a) of the test signal and the digital signal DE ₁ (output value b) of the echo first wave signal stored in the RAM 94. The percentage of this ratio is represented by (b / a) × 100 (%). Usually, this percentage is 100% or less.

The CPU 72 judges that the smaller the echo first wave signal with respect to the test signal (the smaller the EVC value) is, the less the reverberation level is in the performance venue, and the larger the echo first wave signal with respect to the test signal (EVC). Is large)
The higher the degree of reverberation, the more the venue is judged to be.
When an echo signal is added to the original sound signal for reproduction, the echo amount of the echo signal is adjusted to a large value when the EVC value is small, and the echo amount of the echo signal is adjusted to a small value when the EVC value is large.

FIG. 7 shows a flowchart showing the operation of the CPU 72. In this figure, IN1 is an input of a digital signal DT ₂ of a test signal, IN2 is an input of a digital signal DE ₁ of an echo first wave signal, and OUT is an output,
M1 is a memory that keeps the maximum value of IN1, M2 is IN2
The memory that keeps the maximum value of MR, the memory that stores the ratio of M1 / M2 in MR, and the output flag of Fo.

First, OUT, M1, M2, MR and Fo are initialized and it is confirmed whether the start / stop signal SS is "H" or "L" (step S2). This is because data is taken in only during the period when the start / stop signal SS is input. When the start / stop signal SS is "H", M1 and IN1 stored in the RAM94
And are compared (step S3). When IN1 is larger than M1, IN1 is set to M1 (step S4). IN
When 1 is smaller than M1, the process proceeds to step S5. In step S5, M2 and IN2 stored in the RAM 94 are compared. When IN2 is larger than M2, IN2 is set to M2 (step S6), and the process returns to step S1. When IN2 is smaller than M2, the process also returns to step S1. As a result, the RAM 94 stores the maximum value M1 of the digital signal DT ₂ of the test signal and the maximum value M2 of the digital signal DE ₁ of the first echo wave signal.

Next, when the start / stop signal SS becomes "L", it is confirmed whether or not the output flag Fo is output. When the output flag Fo is output (Fo = 0), the process returns to step S1. When the output flag Fo is not output (Fo = 1), the process proceeds to step S8, and M1 and M2 are compared. When M1 is larger than M2, M1 / M2 is set to MR (step S9).
When M1 is smaller than M2, M1 / M2 is set as MR (step S10), and MR is multiplied by (-1) (step S11). These MRs are stored in RAM94 and are stored in C
It is output from the PU 72 (step S12). Then M
1, M2, Fo are initialized (step S13) and the process returns to step S1.

Next, this output MR (FIG. 5c) is D / A
The converter 74 performs D / A conversion (FIG. 5e), and the peak hold circuit 76 outputs the sustain potential. The output signal and a signal (reset signal R (FIG. 5d)) obtained by inverting the start signal S by the inverter 58 are given to the mixer 90 and amplified by the amplifier 92. The reset signal R is a signal for maximizing the attenuation of the echo volume 36 and keeping the echo function stopped (the ratio of the echo first wave signal to the original sound signal is 0) while the device 3 is operating.

The signal output from the amplifier 92 becomes the echo amount control signal EVC of the motor 40 of the echo volume 36 (FIG. 5f).

FIG. 8 shows the echo amount control signal EVC (current value)
An example of a state in which the attenuation degree of the echo volume 36 is adjusted with respect to FIG. In this figure, in a performance hall where the degree of reverberation is relatively low, the value of the reverberation amount control signal EVC is, for example, 0.33. Therefore, the echo reverberation amount is set to 50% with respect to the original sound signal. Adjust. vice versa,
In a performance venue where the degree of reverberation is relatively high, the value of the reverberation amount control signal EVC is, for example, 0.67, so that the ratio of the echo first wave signal to the original sound signal is set to 25% to reduce the reverberation amount of the echo. Is adjusted to.

If the echo first wave E ₁ does not exist, the echo amount control signal EVC is not generated, so the ratio of the echo first wave signal to the original sound signal is set to the standard state of 75%.

Next, the operation of this device 3 for adjusting the echo time of the echo added to the audio signal (echo time control signal E
The output of TC) will be described.

In this case, the shorter the arrival time of the echo first wave signal from the test signal (the larger the ETC value), the higher the degree of reverberation is judged to be in the performance venue, and the echo signal of the echo first wave signal is changed from the test signal. The longer the arrival time (the smaller the ETC value), the lower the degree of reverberation is judged to be in the performance venue. When an echo signal is added to the audio signal and reproduced, the echo time of the echo signal is adjusted to be long when the ETC value is large, and the echo time of the echo signal is adjusted to be short when the ETC value is small.

First, the aforementioned start / stop signal SS
Is output by the slope signal generator 80 as a signal in which the voltage linearly rises when it becomes “H” and becomes 0 when it becomes “L”. From this output (Fig. 5h), the peak hold circuit 82 outputs the sustain potential. This output signal F
The output value of (FIG. 5i) is changed according to the length of time that the start / stop signal SS changes from “H” to “L”. That is, in FIG. 5i, the echo first wave signal D
The output of the signal F has a small value (101 in the figure) when E ₁ arrives in a short time, and has a large value (102 in the figure) after a long time. The signal F and the reset signal R (FIG. 5d) are mixed by the mixer 84, amplified by the amplifier 86, and the signal U is output (FIG. 5k).

On the other hand, when the start / stop signal SS becomes "H", the switch circuit 88 is operated and the ETC
The signal W having the maximum value of is output (FIG. 5j).

Then, the signal U and the signal W are given to the subtraction circuit 94, and this difference signal becomes the control signal ETC (current value) of the motor 42 of the echo / reverb delay circuit 38 (FIG. 5).
k).

As shown in FIG. 5k, during the operation of this device 3 (measurement of reverberation time), the ETC value is kept at the maximum Te, and the echo function is stopped (reverberation time is the longest). .

FIG. 9 shows an example of a state in which the attenuation of the echo / reverb delay circuit 38 is adjusted with respect to the echo time control signal ETC (current value). In this figure, in a venue where the degree of reverberation is low, the value of the reverberation time control signal ETC is, for example, 0.33 (103 in FIG. 5k), so the reverberation time of the echo first wave signal is adjusted to 170 msec. Conversely, if the venue has a high degree of reverberation, the reverberation time control signal ETC
The value of is, for example, 0.67 (104 in FIG. 5k), so that the echo reverberation time of the echo first wave signal is set to 210 msec and the echo reverberation time is adjusted to be long.

Next, regarding the reverb added to the audio signal, when the echo reverberation amount and the reverberation time are set, an element (for example, a reverb signal which complements between the echo and inserts the reverb signal). It is set arbitrarily by using Yamaha YSS205).

Although the number of echo reverberations is fixed in this embodiment, it may be changed based on the test signal and the test reflection signal.

[0045] Incidentally, in this embodiment uses a test signal T ₂ that the test signal T ₁ t2 delayed, may be used a test signal T _1.

[0046]

According to the automatic echo sound adjusting device of the first aspect, the test signal is added to the voice signal based on the test signal and the test reflection signal which is the electric signal of the echo sound of the test sound output from the speaker. The reverberation amount and the reverberation time of the reverberation sound to be generated are set. Therefore, the optimum reverberant sound can be automatically added to the audio signal according to the reverberant characteristic of the performance hall.

[Brief description of drawings]

FIG. 1 is a diagram showing a basic configuration of an echo sound automatic adjustment device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a block diagram of an automatic echo sound adjusting apparatus according to an embodiment of the present invention.

FIG. 3 is a diagram showing a control circuit.

FIG. 4 is a diagram showing a time chart showing the operation of the above-described automatic echo sound adjustment device.

FIG. 5 is a diagram showing a time chart showing the operation of the above-described automatic echo sound adjusting device.

FIG. 6 is a diagram showing a digital signal of a test sound and a digital signal of a first echo wave.

FIG. 7 is a diagram showing a flowchart of the operation of the CPU 72.

FIG. 8 is a diagram showing a state in which the degree of attenuation of the echo volume 36 is adjusted with respect to the echo amount control signal.

FIG. 9 is a diagram showing a state in which the degree of attenuation of the echo / reverb delay circuit 38 is adjusted with respect to the echo time control signal.

[Explanation of symbols]

 20 ・ ・ ・ Microphone 22 ・ ・ ・ Amplifier 30 ・ ・ ・ Speaker 32 ・ ・ ・ Control circuit 34 ・ ・ ・ Test signal output circuit 36 ・ ・ ・ Echo amount adjustment circuit 38 ・ ・ ・ Echo time adjustment circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location H04R 3/04 9381-5H G10K 15/00 L (72) Inventor Natsuo Akiyama Higashishinagawa, Shinagawa-ku, Tokyo 2-2-43 Toshiba Toshiba MI Corporation

Claims (1)

[Claims] 1. A microphone for inputting voice and converting the voice signal into an electric signal, an amplifier for amplifying the voice signal input from the microphone, and a reverberation amount control signal for changing the reverberation amount of the reverberation sound added to the voice signal. A reverberation amount adjustment circuit that adjusts based on the reverberation time control signal that adjusts the reverberation time of the reverberation sound that is added to the audio signal, and a speaker that outputs the audio signal as voice. An adjusting device, which is provided at a predetermined portion of the device, outputs a predetermined test signal, outputs a predetermined test signal, inputs a test signal, and outputs the test signal from a speaker as a test sound, which is reflected by a reflecting surface. The test reflection signal, which is input to the microphone as an electric signal, is input, and based on the test signal and the test reflection signal, Output the reverberation amount control signal to the reverberation amount adjustment circuit,
An echo sound automatic adjustment device, comprising: a control unit that outputs an echo time control signal to an echo duration adjustment circuit.