JP2007201896A - Voice signal amplifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voice signal amplifier for adding the echo to original voice, amplifying the voice to output it from a speaker and suppressing occurrence of howling caused by adding the echo in which a means for adding an echo is simple and which is simply manufactured and adjusted. <P>SOLUTION: The voice signal amplifier makes a level detector 10 detect a level of an electric signal concerning the voice input from a microphone 3, when a detected value is larger than a preset value for probably causing the howling, regards that the voice from the speaker 17 is amplified by feeding back to the microphone 3 and performs control so that the content of a delay signal from a delay circuit 7 is changed so as to avoid that the same voice is continuously picked up by the microphone 3 by a control means 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The singer sings along with the back performance music based on the recording medium or the back performance music based on the telephone signal, picks up the singing sound with a microphone and converts it into an electrical signal A so-called karaoke performance singing is known in which the electric signal is amplified and output from a speaker as a loud sound.
When performing this karaoke performance singing, the singing voice from the singer is picked up by the microphone, amplified, and output from the speaker. In some cases, the singing voice or the like output from the speaker is subsequently picked up again by the above-described microphone by reflection or the like and re-amplified and output.
In such a case, a voice that is not desired for a singer or the like is further amplified and continuously output, and a so-called howling phenomenon occurs.

On the other hand, the singing voice of the singer is not picked up by the microphone and simply amplified and output from the speaker, but the same voice is slightly delayed with respect to the original voice (singing voice) uttered by the singer Is generated and added, then amplified and output, so that the output sound is processed into sound that is obtained as a result of reverberation, that is, so-called echoed sound, sound with echo added The output of is well known.
The present invention generates and adds a sound that is slightly delayed in time to the original input sound, and amplifies and outputs an audio signal that has been echoed by performing the addition process. About.
In particular, the present invention relates to an improvement for avoiding a state in which a howling phenomenon occurs when a howling phenomenon occurs in sound output in the sound signal amplifying apparatus having such a configuration.

As described above, in a karaoke performance singing or the like that is output by adding echo to the original voice of the singer input from the microphone, the original voice that is amplified and output from the speaker is picked up by the microphone again together with the echo component. It is known that a howling phenomenon occurs when the signal is further amplified and output.
Howling is an unpleasant sound for singers, those who are present at the venue, and the like. On the other hand, the following documents are known as techniques for providing an echo to the original voice and for avoiding or stopping the howling phenomenon.

JP 2002-215179 A

An echo signal generator disclosed in Japanese Patent Application Laid-Open No. 2002-215179 (hereinafter referred to as “prior art invention”) is a system in which an electrical signal related to sound from a microphone amplifier 2 flows into a mixer 6, and a microphone amplifier 2 is connected to the echo amount adjusting mixer 5 via the reverb amplifier 3 and the delay amplifier 4 and flows into the mixer 6.
Since the prior art invention has such a configuration, in the mixer 6 and later, a signal delayed in time with respect to the electrical signal from the microphone amplifier 2 follows, and an electrical signal related to the echoed sound is obtained at the output terminal. It has become.

In the prior art invention, an echo amount adjustment mixer 5 is connected after the reverb amplifier 3 and the delay amplifier 4, and when the echo amount adjustment mixer 5 is adjusted so that the echo amount increases, the reverb echo signal once rises. The delay echo signal has a characteristic of descending later, and the delay echo signal has a characteristic of gradually increasing.
With this configuration, when the amount of echo is small, the reverb echo signal is the center, and when the amount of echo is large, the delay echo signal is the center, so it is possible to select the echo signal according to the user's preference, Since it is not necessary to set the amount of echoes excessively, an effect of avoiding howling is obtained.

As is apparent from the claims, the detailed description of the invention, and the drawings, the prior art invention is not intended to simply amplify and output the sound picked up by the microphone 1, but to output it by adding an echo. The reverb amplifier 3 and the delay amplifier 4 are provided.
Therefore, the prior art invention includes two means for adding an echo, and the configuration is complicated accordingly.

The prior art invention was made for the purpose of making it difficult for howling to occur, clearly from the description of the problem to be solved by the invention, under the configuration provided with such two echo adding means. .
With respect to such an object, the prior art invention is configured such that howling hardly occurs by causing the echo amount adjustment mixer 5 to function as described above.

On the other hand, the prior art invention does not disclose means for automatically controlling the reverb amplifier 3, the delay amplifier 4, and the echo amount adjusting mixer 5.
Therefore, in the prior art invention, it is considered that it can be received that the functions of the reverb amplifier 3 and the delay amplifier 4 are determined (set) in advance by adjusting and setting the echo amount adjusting mixer 5. Therefore, in order to make it difficult for howling to occur with such a configuration, at least one of the reverb amplifier 3 and the delay amplifier 4 or the echo amount adjustment mixer 5 needs to be adjusted in advance, and the handling becomes complicated accordingly. Problem arises.
On the other hand, a simple configuration including only one of the reverb amplifier 3 and the delay amplifier 4 can be considered as means for adding an echo.
However, with such a configuration, there arises a problem that it is impossible to cope with howling cancellation, and it is impossible to cope with the original purpose of the prior art invention.

  The present invention has been made in view of the above circumstances, and converts the sound input to the microphone into an electrical signal, amplifies it, outputs it again as a sound, and echoes the amplified sound to be output. In a sound signal amplifying apparatus that generates components, adds them, and outputs them from a speaker, the howling can be avoided when the microphone picks up the sound from the speakers and amplifies and outputs the sound again. On the other hand, the purpose is to simplify the manufacturing and handling because the configuration is simple and adjustment is not necessary.

The inventor of the present invention, in an audio signal amplifying apparatus having an echo addition function, the audio from the speaker is picked up by the microphone by reflection or the like and amplified again and output as audio. While the output level increases and results in a howling state, the same sound is output from the speaker as much as the echo component is added to the sound from the speaker. We considered that it is highly likely that the microphone will pick up the same sound in response to the output.
In view of this, the inventors have paid attention to creating a state in which the same sound does not overlap by changing the delay signals constituting such a state, and have completed the invention.

Here, since the original sound is added to the delayed signal, that is, the echo component, an echoed sound can be obtained.
That is, according to the present invention, the sound picked up by the microphone and amplified as a result is output from the speaker, the sound from the speaker is picked up again by the microphone and converted into an electric signal, and the electric signal is amplified again. In this case, whether or not a howling component is included in the amplified electrical signal is detected based on the level of the electrical signal, and if it is determined that the howling component is included, This is an audio signal amplifying apparatus that is controlled so as to shift the timing of adding echoes to the voice and / or to reduce the degree of echoes.

Its detailed configuration consists of a microphone that inputs sound, converts it into an electrical signal, and outputs it, and is connected to the back side of the microphone and inputs the electrical signal from the microphone, and delays in time to create an echo. A delay unit that generates and outputs the electrical signal, a mixer unit that performs addition processing of the electrical signal from the delay unit and the electrical signal from the microphone, and a mixer unit connected to a subsequent stage of the mixer unit, Amplifying means for amplifying the electrical signal to a desired level, and a speaker connected to the subsequent stage of the amplifying means for converting the electrical signal from the amplifying means into sound and outputting the sound,
In addition, a level detector that is connected to the subsequent stage of the microphone and detects the level of the electric signal from the microphone, and is connected to a subsequent stage of the level detector, and the detection result of the level detector is higher than a preset level. When the delay time is larger, the delay means delays the delay electrical signal generated by the delay means at a time different from the initially set time, and / or lowers the output level of the delay electrical signal to zero. An audio signal amplifying apparatus provided with a control means for performing control.

Here, detecting the level of the electrical signal related to the sound picked up by the microphone means that the electrical signal obtained by adding (mixing) the initial electrical signal related to the original sound and the delayed electrical signal. When a signal is converted into sound and output, the echoed sound is reflected and picked up by the microphone and amplified again. Only the sound component picked up by the microphone is picked up by the microphone. As a result, it is possible to obtain a higher level of the electric signal than the electric signal related only to this, and it may cause the howling to occur because the level of the electric signal increases gradually and diverges and howling occurs. This means that it is substantially determined whether or not an electric signal is being amplified.
Also, in the audio signal amplifying apparatus having such a configuration, after the mute means blocks the output of the electric signal to the delay means in order to avoid the howling phenomenon, the level of the electric signal from the microphone causes the howling phenomenon. Since the original value is returned to the original value, there is a configuration in which the control means adds a function of controlling the mute means to release the interruption of the output of the electric signal to the delay means.

  The present invention has a simple configuration by adding only the delay means for generating and outputting a delayed electrical signal with respect to the electrical signal related to the original speech for adding an echo component to the original speech. When there is a high possibility that howling will occur due to the return of the sound of the echo component to the microphone, this fact is determined based on the level of the electric signal from the microphone, and the echo component should be added to the original sound as it is. Can you? Should echo components with different contents be added? , It is configured to automatically discriminate on the basis of the detection result of the level of the electric signal obtained by converting the input voice, so that it is easy to handle without requiring complicated adjustments at the time of manufacture or use. Thus, the electric signal amplifying apparatus has a function of adding an echo component that easily avoids howling.

The present invention will be described based on the best mode shown in the drawings. However, the present invention is not limited by this form.
As shown in the drawing, the audio signal amplifying apparatus 1 includes a performance signal output means 2, a microphone 3, an amplification means 4, a mute means 5, an A / D converter 6, a delay means 7, and a D / A conversion. A device 8, an A / D converter 9, a level detector 10, a control unit 11, an operation unit 12, a display unit 13, a mixer unit 14, a mixer unit 15, an amplification unit 16 and a speaker 17. Is provided.

The performance signal output means 2 outputs an analog electric signal for back performance to a singer by reproducing a desired recording medium (not shown), and is a so-called karaoke performance sound. An electric signal for generating is output.
Therefore, when the performance signal output means 2 is output, as a result, it is possible to obtain a back performance sound output from the speaker 17.
Specific recording media include CDs, MDs, magnetic tapes, and the like, which are reproduced by reproducing means corresponding to each recording medium.
When the voice of a singer who performs karaoke singing is input, the microphone 3 converts the voice into an electrical signal and outputs the electrical signal.

The amplifying means 4 is normally called a microphone amplifier, and is connected to the subsequent stage of the microphone 3 to amplify an electric signal from the microphone 3 to a predetermined level.
In the ON state, that is, the function state, the mute means 5 blocks the transmission of the electric signal output from the microphone 3 and amplified by the amplifying means 4 to the delay means 7. On the other hand, when the mute means 5 is in the OFF state, that is, the function is released, it functions so that the electric signal output from the microphone 3 and input via the amplifier means 4 is simply passed and flows in the direction of the delay means 7. It is.
The A / D converter 6 converts the analog electrical signal from the mute means 5 into a digital electrical signal and outputs it.

When the delay means 7 inputs a digital electric signal related to the original voice of the singer from the microphone 3, an electric signal delayed in time with respect to the input time (initial time) in order to make an echo. Is output.
Specifically, the delay means 7 in the audio signal amplifying apparatus 1 is 129 milliseconds (ms) to 251 milliseconds with respect to the electric signal at the initial time related to the input voice, that is, the output time of the original electric signal. The output is delayed within the range of.

The value of the delay time from 129 milliseconds to 251 milliseconds is an empirically obtained delay time of a delay component that can be heard comfortably with respect to the output time of the original song when performing a karaoke song. is there. However, if necessary, it is not necessary to limit the delay range to this value, and it is desirable that it can be set as appropriate.
The delay time of the delayed electrical signal generated and output by the delay means 7 relative to the original electrical signal is controlled by operating the echo delay input section (not shown) of the operating means 12. Is set according to the operation.

In addition, the delay means 7 is configured to be able to generate and output a single delayed electrical signal or a plurality of delayed electrical signals with respect to the electrical signal related to the original sound, that is, the initial electrical signal. Yes. That is, the number of delay signals generated / output by the delay means 7 is selectable.
The plurality of delay electric signals are, for example, a first wave delay electric signal, a second wave delay electric signal, and a third wave at a constant interval (delay time interval) within a range of 129 milliseconds to 251 milliseconds. It is also possible to generate and output a wave delay electrical signal (see FIG. 2), and to set different time intervals between adjacent delay electrical signals. (See FIG. 3).

That is, the audio signal amplifying unit 1 is different from the generation and output of the plurality of delayed electrical signals with the same periodicity when the delay unit 7 generates and outputs a plurality of delayed electrical signals. It is possible to generate and output at intervals.
On the other hand, in the audio signal amplifying apparatus 1, the delay means 7 includes a first-wave delayed electric signal, a second-wave delayed electric signal, a third-wave delayed electric signal with respect to the electric signal related to the original sound, ··························································································· /

The degree of attenuation of the first-wave delayed electrical signal, second-wave delayed electrical signal, third-wave delayed electrical signal,... Alternatively, it is configured to be able to fade with a certain difference (see FIG. 2) and to decline to a certain degree with a certain intention (see FIG. 3).
That is, the delay means 7 specifically includes an electric signal with a first wave delay with respect to an electric signal related to the original sound, an electric signal with a second wave delay with respect to the electric signal with the first wave delay, An electric signal with a third wave delay with respect to an electric signal with a two-wave delay, an electric signal with a fourth wave delay with respect to an electric signal with a third wave delay,. It can be attenuated by 3 dB.

In the initial state of the audio signal amplifying apparatus 1, the delay means 7 specifically uses the first-wave delayed electrical signal for the original audio-related electrical signal and the second-wave delayed electrical signal for the first-wave delayed electrical signal. An electric signal with a wave delay, an electric signal with a third wave delay with respect to an electric signal with a second wave delay, an electric signal with a fourth wave delay with respect to an electric signal with a third wave delay,... Each is set to attenuate at -3 dB.
On the other hand, when the control means 11 determines that howling occurs when the audio signal amplifying apparatus 1 is used while the delay means 7 is functioning, that is, when a control signal is sent from the control means 11 to the delay means 7. Specifically, the delay means 7 is -3 dB for the first-wave delayed electrical signal relative to the original electrical signal for the original sound, -4 dB for the second-wave delayed electrical signal for the first-wave delayed electrical signal, An electric signal with a third wave delay with respect to an electric signal with a second wave delay is -2 dB, an electric signal with a fourth wave delay with respect to an electric signal with a third wave delay is -4 dB, and an electric signal with a fourth wave delay Is set so as to attenuate the electric signal of the fifth wave delay by -3 dB.

Further, even if there is only one delayed electrical signal, it is possible to attenuate the electrical signal related to the original sound to an arbitrary degree.
Further, the degree of attenuation of the delayed electric signal is determined depending on the environment in which the audio signal amplifying apparatus 1 is used, the comfort for the listener, and so on, and therefore it is desirable to set appropriately. Also from this fact, it is significant that the degree of attenuation of the delayed electric signal of the delay means 7 can be adjusted.
In addition, when generating and outputting a plurality of delayed electrical signals, the delay means 7 is configured to be able to set a combination of the delay time and the degree of attenuation between the adjacent delayed electrical signals.

The D / A converter 8 receives the digital delayed electrical signal from the delay means 7, converts it into an analog electrical signal, and outputs it to the mixer means 14.
The A / D converter 9 receives an analog electric signal from the amplifying means 4, converts it into a digital electric signal, and outputs it to the level detector 10.
The level detector 10 detects the level of the electric signal related to the sound from the amplifying means 4, that is, the level corresponding to the sound of the singer's song picked up by the microphone 3 as a result. The obtained level (value) is sent to the control means 11.

Here, the electric signal related to the sound from the amplifying means 4 located at the subsequent stage of the microphone 3 is also input to the level detector 10 but also to the delay means 7 side. Therefore, the detection of the level of the input signal of the level detector 10 also detects the level of the electric signal to the delay means 7.
If the control means 11 determines that the detection value (level) of the level detector 10 is greater than a preset value, the first wave delay electric signal, the second wave delay electric signal, and the third wave delay ,... At a time interval different from the initial time interval or / and the first wave delay electric signal, the second wave delay electric signal, and the third wave delay electric signal. A control signal for outputting a signal,..., An electrical signal output with a degree of attenuation different from the initial value is sent to the delay means 7.

Further, the control means 11 determines that the detection value (level) of the level detector 10 is larger than a preset value, and based on this determination, sends a control signal to the delay means 7 to generate a delayed electrical signal. Even if the output contents are controlled, if the detection value of the level detector 10 indicates a possibility that divergence may occur larger than a preset value, the electric power from the amplification means 4 to the A / D converter 6 A control signal that is turned ON is sent to the mute means 5 so as to stop the flow of signals.
Even if the control means 11 determines that the detection value (level) of the level detector 10 is greater than a preset value and sends a control signal to the delay means 7 to perform control, the detection of the level detector 10 In the case where the value of is greater than a preset value and indicates a divergence state, the output level of the delayed electrical signal of the delay means 7 is controlled to be 0 instead of turning the mute means 5 ON. It may be a configuration. In such a configuration, the mute means 5 can be omitted.

However, the larger the variable range of the output level of the delay electrical signal of the delay means 7, the more complicated the configuration and control contents of the delay means 7, so that the output level of the delay electrical signal is made zero. It is desirable to appropriately select which of the mute means 5 and the delay means 7 is used.
Here, the preset value for the level detection result means that when the singer's voice collected by the microphone 3 is converted into an electrical signal and output, the level value of the electrical signal is specifically set to 3 mV. Has been.

The level value of the electric signal can be arbitrarily set in the range of 1 to 140 mV depending on the environment in which the apparatus is used, for example, the size of the karaoke room and the desire of the person performing the karaoke song. .
When the level of the electric signal from the microphone 3 is 3 mV, the level of the electric signal amplified by the amplifying means 4 and output to the mixer 14, the mute means 5 and the A / D converter 9 is amplified to 210 mV. It has become.

Here, the electric signal inputted to the A / D converter 9 is converted into a digital electric signal and sent to the level detector 10, and the level detector 10 sends the level value to the control means 11. However, the control means 11 is amplified to 3000 mV and sent to the control means 11 so that the comparison / determination in the control means 11 can be performed accurately and precisely.
That is, the level of the electric signal from the microphone 3 in the control means 11 is amplified and used for discrimination, but the control means 11 is configured to be able to make a substantial level discrimination corresponding to the amplification. Yes.

An amplifier means for performing such amplification is interposed between the level detector 10 and the control means 11, but is omitted in the drawing. Further, the amplifier means for performing such an amplification function may be configured to be connected to the preceding stage of the A / D converter 9.
Therefore, when the control means 11 detects the level of the electric signal from the level detector 10 side, theoretically, the sound from the speaker 17 is picked up again by the microphone 3 depending on whether or not it is greater than 3000 mV. As a result, it is compared and determined whether or not the value of the signal level is increased.

However, it is highly conceivable that the sound from the speaker 17 is reflected, picked up by the microphone 3 and output as an audio signal again in an ordinary karaoke room where the wall is not a perfect silencing wall. It is.
What is important here is that the amount of feedback that occurs at that time should be less than or equal to that which makes it uncomfortable for a karaoke singer or a person who is present on the spot. A value larger by 2% of the allowable range, that is, 3060 mV is set as a preset value.

However, depending on the environment in which this device is used, the possibility of howling and the extent of howling will change, and the degree of perception of howling for those who sing karaoke and those who live there Since it differs greatly individually, a value of 2% indicating this margin can be arbitrarily set from the operation means 12.
Note that the feeling of unpleasantness that occurs here means that the environment in which the entire apparatus including the microphone 3, the speaker 17 and the like are placed changes during use, that is, for example, a singer moves. By changing the position of the partition, the relative positional relationship of the speaker 17, the sound reflector, and the microphone 3 of the singer changes, and the state changes to a state in which no howling occurs from the middle. This means that howling works strongly even if there is a margin.

On the other hand, when a state in which howling is avoided as much as possible is desired, the environment in which the audio signal amplifying apparatus 1 is used is greatly affected, but the discrimination value of the control means 11 for the detection result of the level detector 10 is made lower. It should be set as follows.
Based on the input content from the operation means 12, the control means 11 sends the original electric signal (the microphone 3 converts the sound into an electric signal from the amplification means 4 to the mixer means 14) to the delay means 7 and outputs it at the initial time. How much time is delayed with respect to the electrical signal) How many electrical signals are generated when a plurality of delayed electrical signals are generated and output for one electrical signal? What is the attenuation of the delayed electrical signal relative to the original electrical signal? , Send a control signal to set.

Further, the control means 11 outputs a drive signal of display contents to the display means 13 so as to display the current state of various functions.
The display means 13 displays the current status of various functions based on the control signal from the control means 11.
The mixer means 14 adds the original electric signal related to the sound from the amplifying means 4 and the delayed electric signal from the delay means 7 via the D / A converter 8, so-called mix, An electrical signal related to the sound of the echo component, that is, a delayed electrical signal is added to the electrical signal related to the voice of the karaoke song.

The mixer unit 15 adds the electrical signal related to the karaoke singing voice to which the echo component from the mixer unit 14 is added and the electrical signal related to the back performance of the singing from the performance signal output unit 2, and sends the result to the amplification unit 16. Is.
The amplifying means 16 inputs the electric signal related to the sound including the echo component from the mixer means 15 and the electric signal related to the back performance, amplifies it to a predetermined level, and sends it to the speaker 17.
The speaker 17 inputs an analog electric signal from the amplification means 16 and converts it into sound and outputs it.

The audio signal amplifying apparatus 1 is configured as described above. The function will be described below.
A user, that is, a karaoke singer, operates the operation means 12 to turn on the main power supply of the entire apparatus. Subsequently, how much time delay is caused with respect to the initial signal from the amplifying means 4 from the operating means 12 to the delay means 7 through the control means 11 so as to obtain a desired echo state at the time of singing. , How many times to set the number of delay electrical signal outputs? What is the level of attenuation of the delayed electrical signal? Set the value for.

Specifically, as shown in FIG. 2, the singer's karaoke singing voice is generated and output after 199 milliseconds with respect to the electrical signal corresponding to the initial time when the microphone 3 is picked up, and the level is -3 dB. An electrical signal related to the first delay voice that is lower than the first delay voice, and is generated and output after 199 milliseconds with respect to the electrical signal related to the first delay voice and is related to the second delay voice whose level is -3 dB lower The electric signal, the electric signal related to the second delayed sound, and the electric signal generated and outputted after 199 milliseconds and the level of the electric signal related to the third delayed sound which is lower by −3 dB, the audio of the third delayed sound Is generated and output after 199 milliseconds with respect to the electric signal according to the fourth, and the electric signal related to the fourth delay sound whose level is lower by −3 dB, and the electric signal according to the fourth delay sound is 199 milliseconds. rear Electrical signal generated and output and level according to the just lower fifth delay of speech -3 dB, performs the setting so ...... is generated and output.
At this time, the singer can confirm the contents of the electric signal related to the set delay from the display means 13.

In addition, the singer sets the value that the control means 11 compares and discriminates with the detection result from the level detector 10 to 3060 mV.
Further, when the detection result from the level detector 10 exceeds 3060 mV and the control means 11 outputs a control signal for changing the contents of the echo addition to the delay means 7, the delay means 7 is based on the control signal. As shown in FIG. 3, a delayed electrical signal having a content different from the initially set content is set for the delayed electrical signal.
In addition, even if the delay means 7 generates and outputs electrical signals with different delays, the detection result of the level detector 10 diverges beyond 3060 mV, resulting in howling and annoying. In the case where it is determined that there is a go or an annoyance, that is, in the case where the detection result from the level detection 10 continues to be 3060 mV or higher, the control means 11 sends a control signal to the mute means 5 that is activated or turned ON. Make settings as follows.

Here, the karaoke singer holds the microphone 3 to be in a standby state and operates the performance signal output means 2 to output a desired back performance (karaoke performance).
At this time, an analog electric signal related to the back performance from the performance signal output means 2 is sent to the mixer means 15, further amplified to a desired level by the amplification means 16, and sent to the speaker 17. The back performance sound is output.

When the back performance sound based on the electrical signal flows from the performance signal output means 2 from the speaker, the karaoke singer starts singing (karaoke singing) in accordance with the back performance from the speaker 17.
Here, the microphone 3 picks up the voice of the karaoke song from the singer, converts it into an analog electric signal, and sends it to the amplification means 4.
The amplifying unit 4 sends an electric signal related to the singing to the mixer unit 14, the mute unit 5 and the A / D converter 9.

The mixer means 14 inputs an analog electric signal related to the voice of the karaoke song from the amplifying means 4 at an initial time when the output time is picked up by the microphone 3.
On the other hand, the mute unit 5 receives an analog electric signal related to the voice of the karaoke song whose output time from the amplification unit 4 is the initial time, but the control unit 11 does not send an ON control signal to the mute unit 5. Therefore, the received analog electric signal is passed through without being cut off and sent to the A / D converter 6.

Further, when the A / D converter 9 receives an analog electric signal related to the singing voice output at the initial time from the amplification means 4, the A / D converter 9 converts the analog electric signal into a digital electric signal and sends it to the level detector 10.
Here, the level detector 10 detects the level of the electric signal from the A / D converter 9 and sends the detection result (level value) to the control means 11.
The control means 11 determines whether or not the detection result from the level detector 10 is larger than a preset value (3060 mV), and if it does not reach the preset value, the delay means 7 and the mute No control signal is sent to the means 5.

At this time, since the sound signal amplifying apparatus 1 is in an initial state of operation, the sound from the speaker 17 is not picked up by the microphone 3, and if the entire apparatus is functioning normally, the detection value of the level detector 10 is detected. Does not occur when the value is larger than a preset value.
Further, the mute means 5 in the initial state functions to release the blocking function, that is, to pass the electric signal from the amplifying means 4 as it is and send it to the A / D converter 6.

Therefore, the analog electric signal related to the sound flowing from the amplifying means 4 to the mute means 5 is converted into a digital electric signal by the A / D converter 6 and sent to the delay means 7.
When a digital electric signal from the A / D converter 6 is input to the delay means 7, an initial time signal output from the microphone 3, that is, an electric signal input from the amplification means 4 to the mixer means 14. A delay signal (digital signal) of a set number which is substantially delayed by the time set by the operation means 12 and set at a set level is generated based on the electrical signal related to the original sound from the amplification means 4, and D / Output to the A converter 8.

  That is, in detail, the electrical signal related to the first delayed sound which is substantially delayed by 199 milliseconds and lower in level by −3 dB relative to the initial time when the microphone 3 picked up the karaoke sound. A signal related to the second delayed sound that is delayed by 199 milliseconds and lower in level by −3 dB relative to the electric signal related to the sound having the first delay, and 199 to the electric signal related to the second delayed sound. An electrical signal associated with a third delay voice that is delayed by milliseconds and having a level lower by -3 dB, delayed by 199 milliseconds and lower in level by -3 dB relative to the electrical signal associated with the third delay voice An electric signal related to the fourth delay sound, an electric signal related to the fifth delay sound that is delayed by 199 milliseconds and lower in level by −3 dB relative to the electric signal related to the fourth delay sound. Delay means 7 generates and outputs to the D / A converter 8.

When the digital five delay signals from the delay unit 7 are input, the D / A converter 8 converts each of the digital delay signals into an analog delay electric signal (an electric signal related to an echo component), and sends it to the mixer unit 14.
Here, both the mixer means 14 are common in that they are picked up by the microphone 3 and converted from sound into an electric signal, but the analog electric signal output from the amplifying means 4 at the initial time and the D / The five analog electrical signals delayed by the delay means 7 via the A converter 8 are added (mixed) and sent to the mixer means 15.

The mixer means 15 is used for back performance from the analog electric signal added with the processed analog electric signal related to the singing voice from the mixer means 14, that is, the analog electric signal to which the delayed electric signal corresponding to the echo component is added, and the performance signal output means 2. The analog electrical signal is added (mixed) and sent to the amplifying means 16.
When the amplifying means 16 receives the analog electric signal subjected to the addition processing from the mixer means 15, it amplifies it to a predetermined level and sends it to the speaker 17.

When the speaker 17 receives the analog electrical signal from the amplification means 16, it converts it into sound and outputs it.
That is, the speaker 17 is a karaoke singer's singing voice from the microphone 3, a voice related to the singing that can be delayed with respect to the singing voice, and a back performance from the performance signal output means 2. The sound concerning is output.

When the speaker 17 outputs sound, a part of the sound hits the wall or ceiling of the room and is reflected, and the sound sent by the reflection (hereinafter referred to as “sound by reflection”) is a microphone. May be picked up by 3.
Here, when the microphone 3 picks up the sound resulting from the reflection, the microphone 3 converts it into an analog electric signal together with the sound of the karaoke song and sends it to the amplification means 4.
The amplifying means 4 amplifies the electrical signals related to the voice by reflection and the voice of karaoke singing as specified, and sends them to the mute means 5, the A / D converter 9 and the mixer means 14.

The A / D converter 9 converts an analog electric signal related to the voice of reflection and the voice of karaoke singing into a digital electric signal and sends it to the level detector 10.
Here, the level detector 10 detects the level of a digital electric signal related to the voice of reflection and the voice of karaoke singing, and sends the value to the control means 11.
The control means 11 receives from the level detector 10 the value of the level of the added digital electric signal related to the voice of reflection and the voice of karaoke singing, and compares the value with a preset value (3060 mV). To determine.

  Here, when the sound by reflection, that is, the sound output from the speaker 17 and reflected and picked up by the microphone 3 as a result is sufficiently small, the level of the electrical signal related to the sound by the reflection is the microphone. 3, the level value of the electric signal related to the voice of the karaoke song picked up together by 3 is sufficiently small, and the control means 11 has a level value from the level detector 10 smaller than a preset value. Therefore, neither the control signal for changing the content of the delay signal is sent to the delay means 7 nor the control signal for causing the mute means 5 to output ON is sent.

Therefore, the mute means 5 sends analog electrical signals related to the sound reflected by the amplification means 4 and the voice of the karaoke song to the A / D converter 6, and the A / D converter 6 sends the analog signal from the mute means 5. Are converted into digital electrical signals related to the voice of reflection and the voice of karaoke singing and sent to the delay means 7.
Here, the delay means 7 delays the above-mentioned preset time with respect to the initial time when it is output from the amplification means 4 and sets a preset number of the above-mentioned preset electrical signals. And output to the D / A converter 8.

When the D / A converter 8 receives from the delay means 7 a digital electric signal related to the reflected voice, the karaoke singing voice, and the delayed voice (sound of the echo component), the D / A converter 8 converts it into an analog electric signal. To the mixer means 14.
In the mixer means 14, analog electric signals relating to the voice of reflection and the voice of karaoke singing outputted at the initial time from the amplification means 4 are input, and the initial time from the D / A converter 8 is inputted. Thus, the analog electrical signals related to the reflected voice and the karaoke singing voice delayed by the preset time are input, and the two analog electrical signals are added and processed and sent to the mixer means 15.

At this time, by the addition processing of the mixer means 14, the electric signal indicating the sound obtained by adding the sound of reflection and the sound of karaoke singing delayed by the set delay time of the delay means 7 to the sound of reflection and the sound of karaoke singing In other words, the analog electrical signal related to the echo component voice is sent to the mixer means 15 after being delayed by the above-mentioned set time with respect to the voice of the reflection at the initial time and the voice of the karaoke song.
The mixer unit 15 receives the analog electric signal from the mixer unit 14 and the analog electric signal related to the back performance from the performance signal output unit 2, and adds the two analog signals to the amplification unit 16. send.

At this time, by the addition processing of the mixer means 15, the back performance is added to the sound that gives the echo effect by delaying the sound by the reflection of the initial time and the sound of the karaoke song by the above-mentioned preset time, that is, the sound of the echo component. An analog electric signal related to the voice is sent to the amplifying means 16.
The amplifying means 16 amplifies the analog electric signal related to the sound from the mixer means 15 as specified and sends it to the speaker 17.
The speaker 17 converts the amplified analog electric signal related to the sound from the amplifying unit 16 into sound and outputs the sound.

Here, the singer and the person present there are the sound picked up by the microphone 13 from the speaker 17, the sound delayed by the sound and becoming an echo component, and the back performance from the performance signal output means 2. You will hear the amplified audio.
At this time, the speaker 17 outputs the sound of the reflection and the sound of the echo component related to the sound, but compared with the sound of the singer uttered to the microphone 3 and the sound of the back performance from the performance signal output means 2. It is so small that it can be ignored, so there is no concern for the singer and those who were there.

On the other hand, when the sound caused by the reflection picked up by the microphone 3 has a certain level or more, the level of the electric signal related to the sound caused by the reflection is related to the sound of the karaoke song picked up by the microphone 3 together. This is a meaningful level compared to the level value of the electric signal. That is, in this case, the audio signal amplifying apparatus 1 specifically functions as follows.
First, when the microphone 3 picks up the voice of karaoke singing and the voice of reflection, it converts it into an electrical signal and sends it to the amplification means 4.

The amplifying means 4 amplifies the electrical signals related to the voice by reflection and the voice of karaoke singing as specified, and sends them to the mute means 5, the A / D converter 9 and the mixer means 14.
The A / D converter 9 converts an analog electric signal related to the voice of reflection and the voice of karaoke singing into a digital electric signal and sends it to the level detector 10.

Here, the level detector 10 detects the level of a digital electric signal related to the voice of reflection and the voice of karaoke singing, and sends the value to the control means 11.
At this time, the level detector 10 detects a level of a value of, for example, 3080 mV for the electrical signal related to the sound from the amplification unit 4 via the A / D converter 9 and sends the value to the control unit 11.

The control means 11 compares the value of the electric signal related to the voice inputted again by the reflection from the level detector 10 and the voice of the karaoke song with a value of 3080 mV with a preset value (3060 mV), and the magnitude relation. To determine.
Here, the control means 11 determines that the value of the level detected by the level detector 10 is larger than a preset value, and subsequently, based on this determination, the delay means 7 changes the content of the delay signal. Send control signal.
Therefore, the delay means 7 is based on the control signal from the control means 11, and the delay signal to be generated from the electric signal that is the source of the voice of reflection and the voice of karaoke singing input through the A / D converter 6. The contents, that is, the delay time with respect to the initial time and the degree of the level are changed to generate a delayed digital electric signal and output to the D / A converter 8.

  That is, specifically, the delay means 7 is generated and output after 199 milliseconds with respect to the electrical signal corresponding to the initial time when the voice of the singer's karaoke song is picked up by the microphone 3, and the level is only −3 dB. The electrical signal related to the low delay first audio, and the electrical signal related to the second delayed audio that is generated and output after 209 milliseconds from the electrical signal related to the first delayed audio and whose level is lower by −4 dB. The signal is generated and output after 189 milliseconds with respect to the electric signal related to the second delayed sound, and the electric signal related to the third delayed sound whose level is lower by −2 dB. The electric signal generated and output after 189 milliseconds for the electric signal and the level of the fourth delay sound that is lower by −4 dB, and the electric signal of the fourth delay sound after 219 milliseconds Adult-output and level electrical signal according to only the lower fifth delay of speech -3 dB, to generate ..... outputs to the D / A converter 8 (see Figure 3).

The D / A converter 8 receives the delayed electrical signal whose delay content has been changed from the delay means 7, converts it into an analog electrical signal, and sends it to the mixer 14.
Here, the mixer means 14 generates / generates an analog electrical signal related to the sound reflected by the amplification means 4 and the sound of the karaoke song, and the initial time from the D / A converter 8. The outputted delayed electric signal (electric signal related to the echo component) is sent to the mixer means 15.

The mixer means 15 includes an analog electric signal subjected to addition processing related to the singing voice from the mixer means 14, that is, an analog electric signal to which an echo component is added, and an analog electric signal for back performance from the performance signal output means 2. Are added (mixed) and sent to the amplification means 16.
When the amplifying means 16 receives the analog electric signal subjected to the addition processing from the mixer means 15, it amplifies it to a predetermined level and sends it to the speaker 17.

When the speaker 17 receives the analog electrical signal from the amplification means 16, it converts it into sound and outputs it.
That is, the speaker 17 is a karaoke singer's singing voice from the microphone 3, a singing voice that can be delayed with respect to the singing voice and constituting an echo component, and a back performance from the performance signal output means 2. The sound concerning is output.

When the speaker 17 is outputting sound, a part of the sound further hits the wall or ceiling of the room and is reflected, and the sound due to the reflection may be picked up by the microphone 3 again.
Here, when the microphone 3 picks up the sound resulting from the reflection, the microphone 3 converts it into an analog electric signal together with the sound of the karaoke song and sends it to the amplification means 4.
The amplifying means 4 amplifies the electrical signals related to the voice by reflection and the voice of karaoke singing as specified, and sends them to the mute means 5, the A / D converter 9 and the mixer means 14.

The A / D converter 9 converts an analog electric signal related to the voice of reflection and the voice of karaoke singing into a digital electric signal and sends it to the level detector 10.
Here, the level detector 10 detects the level of a digital electric signal related to the voice of reflection and the voice of karaoke singing, and sends the value to the control means 11.
The control means 11 receives the value of the level of the digital electric signal related to the voice by reflection and the voice of karaoke singing from the level detector 10, and discriminates the magnitude comparison between the value and a preset value (3060 mV). Will do.

Here, even if the sound by reflection, that is, the sound output from the speaker 17 and reflected and picked up by the microphone 3 as a result, especially the sound of the echo component is at a certain level, the sound by the first reflection and the delay means. Since the delayed electrical signal generated or output after 7 is controlled by the control means 11, that is, the electrical signal indicating the echo component is shifted in time in the periodicity, the level of the delayed electrical signal is also kept low. The same sound overlaps each other, and the level of the electric signal related to the overlapped sound becomes higher and higher, resulting in howling, and further the level of the electric signal related to the howling diverges. The fear is suppressed.
Note that the generation and output of the delayed electrical signal by the delay means 7 is different from the content that was initially set, that is, the content that the karaoke singer is most desirable, but because the delayed electrical signal, that is, the echo component is added, As compared with the sound output from the speaker 17 after being amplified without adding any echo component, comfort is obtained.

In such a case, even if the microphone 3 picks up the sound including the sound caused by the reflection emitted from the speaker 17, the picked-up sound does not overlap the sound of the original sound and the sound of the echo component related thereto and / or causes howling. As a result, the electric signal that is converted from the sound by the microphone 3 at this time is amplified by the amplifying device 4 and then passed through the A / D converter 9. Then, the level is detected by the level detector 10 and the detection result is sent to the control means 11.
Here, the control means 11 determines whether or not the level relating to the electrical signal output from the level detector 10 at this time by the microphone 3 remains higher than a preset value.

If the control means 11 determines that the detection level from the level detector 10 is smaller than a preset value, there is no possibility of howling, and therefore the delay signal having the initial setting contents shown in FIG. 2 is output. In this manner, a control signal is output to the delay means 7.
When the delay means 7 receives such a control signal from the control means 11, the delay means 7 switches the delay signal having the contents shown in FIG. 3 to the delay signal having the contents shown in FIG. Output.

Here, the electric signal picked up by the microphone 3 and converted from the sound and output is amplified by the amplifying means 4 and sent to the mixer 14 and consequently to the delay means 7.
In the mixer 14, the original electrical signal output from the amplification means 4 at the initial time, the delay time, the level attenuation level, and the number of delayed signals with respect to the original signal are as shown in FIG. Mix the delayed signal. Therefore, as a result, there is a possibility that howling will occur, so that the delayed sound in a state before the delay means 7 changes the content of the delayed signal, that is, the sound to which the echo component is added is output from the speaker 17.

On the other hand, if the control means 11 determines that the detection level from the level detector 10 is greater than a preset value, there is a possibility that howling will occur and further diverge, so that the contents shown in FIG. A control signal is output to the delay means 7 so as to output a delayed signal with a delayed level and attenuated level with respect to the original signal.
When receiving the control signal having such contents from the control means 11, the delay means 7 generates a delay signal corresponding to the control signal and outputs it to the D / A converter 8.

The D / A converter 8 converts the digital delayed electrical signal from the delay means 7 into an analog electrical signal and sends it to the mixer means 14.
The mixer means 14 receives an analog electrical signal related to the original sound from the amplification means 4 and a delayed analog electrical signal that becomes an echo component for the original sound from the D / A converter 8, and performs mixing. And output to the mixer means 15.
The mixer unit 15 adds the electrical signal related to the sound from the mixer unit 14 and the electrical signal related to the back performance from the performance signal output unit 2, and sends the result to the amplification unit 16.

Amplifying means 16 amplifies it to a predetermined level and outputs it to speaker 17 when it receives an analog electrical signal of the voice relating to the karaoke singing and the voice relating to the back performance from mixer means 15.
The speaker 17 converts an analog electrical signal related to sound into sound and outputs the sound.
Here, in addition to the voice of the karaoke singer's singing, the microphone 3 may pick up the voice output from the speaker 17 and reflected.
At this time, the level of the electric signal obtained by the microphone 3 picking up and converting the sound is compared with a preset value by the control means 11 as described above.

Even if the control means 11 changes the content of the delay signal from the initial setting, if the level of the electrical signal related to the sound from the amplifying device 4 is greater than a preset value, the control means 11 Even if the delay time or level of the delayed electrical signal is changed with respect to the electrical signal related to the sound, it is determined that there is a possibility that howling may occur as a result of overlapping with the original sound, and further that divergence may occur. Then, a control signal is sent to the mute means 5 to turn it on, that is, to cut off.
When the mute means 5 receives such a control signal, the mute means 5 will not cut off and send it to the A / D converter 6 even if an electric signal related to the original sound is inputted from the amplifying means 4.

At this time, an analog electric signal picked up by the microphone 3 and converted from the sound and output is amplified by the amplifying means 4 and sent to the mixer means 14, the mute means 5 and the A / D converter 9. It is not sent to the delay means 7 via the mute means 5 and the A / D converter 6.
Therefore, since the delay means 7 does not receive the original electric signal, it does not generate a delay signal and output it to the mixer means 14 side.

Therefore, when the analog electric signal related to the original sound is input, the mixer means 14 sends the analog electric signal to the mixer means 15 as it is because there is no object to be mixed.
The mixer means 15 inputs an electric signal related to the karaoke singing sound from the mixer 14 and an electric signal related to the karaoke performance from the performance signal output means 2, mixes the two electric signals, and then supplies the electric signal to the amplifying means 16. send.

The amplifying means 16 amplifies the electric signal from the mixer means 15 to a predetermined level and then sends it to the speaker 17.
The speaker 17 converts the electrical signal from the amplification means 16 into sound and outputs it.
At this time, the voice from the speaker 17 is only the voice of the original karaoke song picked up by the microphone 3 and the voice of the karaoke performance from the performance signal output means 2, and becomes an echo component for the voice of the karaoke song. Audio is not included.

Therefore, even if the sound output at this time is reflected and picked up by the microphone 3, there is no echo component, so the same sound is picked up by the microphone 3 and output from the speaker 17, and the same sound is reflected again from the speaker 17. There is no situation in which the same sound overlaps and the level of the electrical signal related to the sound increases as the sound is picked up by the microphone 3 repeatedly.
Therefore, the audio signal amplifying apparatus 1 avoids a state in which howling occurs due to an echo component being added to the original sound and a state of howling.

As described above, the generation and output of the delayed electric signal of the delay means 7 is stopped by the control of the mute means 5. However, the output of the delay means 7 is stopped, that is, the generation of the delay signal and / or the output is stopped. It is also possible by stopping.
Further, although the mute means 5 is connected to the upstream side of the delay means 7, the mute means 5 may be connected to the downstream side of the delay means 7.

Here, the audio signal amplifying apparatus 1 is simple because the configuration for adding an echo component to the original audio consists only of a system including the delay means 7.
Also, in the audio signal amplifying apparatus 1, howling occurs when the audio with the echo component added to the original audio is amplified and output, whereas the microphone 3 picks up and converts it from the audio. It is determined by comparing the level of the obtained electric signal with a preset value that there is a possibility of howling.

  Here, in the audio signal amplifying means 1, when it is determined that howling occurs due to the determination of the level, an echo component due to reflection is repeatedly added to the original audio picked up by the microphone 3, thereby generating a specific audio If the echo component overlaps multiple times, the level of the electrical signal related to the sound will increase gradually and may diverge, and the echo component will be added repeatedly to the specific original sound. In order to prevent this, since the function of the delay means 7 can be controlled by the control means 11 so as to convert the contents of the delayed signal that is a prime component of the echo component, complicated adjustment and control are performed on the entire apparatus and each means. This makes it possible to avoid the occurrence of howling without necessity.

Therefore, in such a configuration, the occurrence of howling is avoided by the discrimination function of the control means 11 and the control of the control means 11 to the delay means 7, so that no complicated adjustment or the like is required for the means. The manufacture of the device itself is simplified.
The audio signal amplifying apparatus 1 includes the contents of the delay signal generated and output by the delay means 7 based on the control signal from the control means 11, that is, the delay time, the attenuation level, and the delay signal with respect to the electric signal related to the original sound. Although the number is changed, it is preferable to appropriately set the change contents and the number of changes of the delay signal in accordance with the ease of howling.

For example, as apparent from FIGS. 2 and 3, the delay signal 7 is output five times before and after the delay unit 7 is controlled by the control unit 11, but howling is strongly avoided. As described above, the number of delayed signals may be reduced before and after the control.
In the audio signal amplifying apparatus 1, the delay unit 7 generates and outputs a plurality of delay signals, but may be configured to generate and output only one delay signal.

In this case, the only delay signal generated and output by the delay means 7 is output with a time lag or / and a further lower output level with respect to the initially set delay time. The echo component due to the delayed signal having such a content is different from the content of the first echo component even when the sound from the speaker 17 is returned to the microphone 3 by reflection, so that there is a high possibility that howling will not easily occur. .
The audio signal amplifying apparatus 1 compares and discriminates the detection result from the level detector 10 with a value preset in the control means 11 and discriminates that the control means 11 is larger than the preset value, and delays the delay means 7. When the content of the electrical signal is changed and the possibility of howling is avoided, the content of the delayed electrical signal from the delay means 7 is returned to the initially set content.

  However, when the echo component having the initially set content is added to the original sound, if there is a high possibility that howling will occur again, the content of the delayed signal generated by the delay means 7 is changed to the initially set content. It is better to configure so that it does not return.

[BRIEF DESCRIPTION OF THE DRAWINGS] It is a block diagram explaining the structure of one Embodiment of this invention. In the best embodiment shown in FIG. 1, it is a graph explaining the relationship between the passage of time before the delay means is controlled by the control means and the output of the delay signal. In the best embodiment shown in FIG. 1, it is a graph explaining the relationship between the passage of time after the delay means is controlled by the control means and the output of the delay signal.

Explanation of symbols

1: Audio signal amplification equipment 2: Performance signal output means 3: Microphone 4: Amplification means 5: Mute means 7: Delay means 10: Level detector 11: Control means 14 and 15: Mixer means 17: Speaker

Claims (3)

A microphone that inputs sound and converts it into an electrical signal and outputs it, and an electrical signal that is connected to the subsequent stage of the microphone and receives the electrical signal from the microphone, and generates an electrical signal that is delayed in time to create an echo And output delay means, mixer means for adding the electrical signal from the delay means and the electrical signal from the microphone, and connected to the subsequent stage of the mixer means, the electrical signal from the mixer means to the desired signal Amplifying means for amplifying to a level, and a speaker connected to a subsequent stage of the amplifying means, converting an electrical signal from the amplifying means into sound and outputting the sound,
In addition, a level detector that is connected to the subsequent stage of the microphone and detects the level of the electric signal from the microphone, and is connected to a subsequent stage of the level detector, and the detection result of the level detector is higher than a preset level. If the delay time is larger, the delay means delays the delay electrical signal generated by the delay means at a time different from the initially set time and / or lowers the output level of the delay electrical signal to zero or zero. An audio signal amplifying apparatus provided with control means for performing control.
When there are a plurality of signals generated and output by the delay means and the detection result of the level detector is larger than a preset level, the control signal is sent to the delay means in time of the delay signals adjacent to each other. The audio signal amplifying apparatus according to claim 1, wherein the audio signal amplifying apparatus is configured to send a control signal for delaying and outputting at different intervals.
It has been determined that the mute means for blocking the flow of the electric signal is interposed between the microphone and the delay means or at least one of the delay means and the mixer means, and the level of the electric signal from the microphone is larger than a preset value. In this case, it is determined that the mute means blocks the flow of the electric signal from the delay means to the mixer means by the function of the control means, and that the level of the electric signal from the microphone is lower than a preset level. The audio signal amplifying apparatus according to claim 1, wherein the control means controls the mute means so as to release the interruption of the output of the delayed electric signal from the delay means to the mixer means.

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