JP2005107264A - Karaoke machine equipped with howling canceler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve points in which a person in charge of operation of a Karaoke machine is preferably able to optionally set whether a canceler operates or is made ineffective since there is no possibility of howling in some installation environment and when the canceler is set effective, an operator feels easy when knowing the operation state of a dynamic howling suppressing circuit while singing karaoke. <P>SOLUTION: A control mens makes the dynamic howling suppressing circuit ineffective when the canceler is set ineffective by user's input, and makes the dynamic howling suppressing circuit effectively operate and enables display processing when the canceler is set effective by user's input, the display processing responding to the user input to display a gain attenuation level by the dynamic howling suppressing circuit on a display means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a karaoke apparatus including a howling canceller, and more particularly to a karaoke apparatus including a dynamic howling suppression circuit that automatically performs a suppression operation when a howling occurs and gradually returns to the original state.

  In order to suppress unpleasant howling, the sound system of a karaoke apparatus is disclosed in JP-A-3-237899, JP-A-2000-92588, JP-A-2000-316199, JP-A-2002-78067, etc. Circuit technology as disclosed has been developed and put into practical use.

As a method of this kind of howling canceller, it functions to detect howling that has occurred in an audio signal amplification system, and gradually attenuate the gain in a specific frequency band in response to the detection operation and then gradually restore it. There is a dynamic howling suppression circuit.
JP-A-3-237899 JP 2000-92588 A JP 2000-316199 A JP 2002-78067 A

  It is desirable that the howling canceller attenuates the gain only in the frequency band in which the howling occurs in a necessary minimum range. If it is not necessary (howling is not occurring), or if it is more than necessary (slightly howling is occurring), if the howling canceller's bandwidth attenuation is used strongly, the frequency response of the amplifier will be reduced. This creates a useless gap, making it impossible to produce a rich and rich musical sound as commonly known as “sound loss”.

The dynamic howling suppression circuit has been developed from the above viewpoint. After detecting howling that has occurred in the audio signal amplification system, the gain in a specific frequency band is attenuated as appropriate in response to the detection operation. It works to gradually restore.
Even with this type of howling canceller, there may be no worrying about howling depending on the installation environment of the karaoke device, so the person in charge of karaoke device operation arbitrarily sets whether the canceller is to be activated or deactivated. It is desirable to be able to do so.
In addition, when the canceller is set to be effective, it is desirable for the person who is performing the setting operation to have a sense of security if the operating state of the dynamic howling suppression circuit is known while actually singing karaoke.

The karaoke apparatus provided with the howling canceller according to the present invention is specified by the following items (1) to (5).
(1) A karaoke apparatus provided with a karaoke performance means, a dynamic howling suppression circuit, and a control means.
(2) The karaoke performance means inputs the audio signal of the accompaniment music to the mixing amplifier and supplies the lyrics subtitle image to the display means.
(3) The dynamic howling suppression circuit detects howling that has occurred in the mixing amplifier system, and in response to the detection operation, attenuates the gain of the specific frequency band as appropriate, and then gradually restores the original.
(4) The control means disables the dynamic howling suppression circuit when the canceller is disabled by user input, and enables the dynamic howling suppression circuit when the canceller is enabled by user input. Operates and enables display processing.
(5) The display process displays the gain attenuation level by the dynamic howling suppression circuit on the display means in response to the user input.

  In the karaoke apparatus configured as described above, the display process is to display the frequency characteristics of the dynamic howling suppression circuit on the display means, or to receive a message for accepting an input for setting the validity / invalidity of the dynamic howling suppression circuit. It can be displayed according to the display means.

  The dynamic howling suppression circuit can be operated as necessary, and the operation state of the circuit can be realized by display.

=== Schematic configuration of karaoke apparatus ===
FIG. 1 shows an example of a hardware-based configuration of a communication karaoke apparatus to which the present invention is applied. The karaoke device is a computer application device equivalent to a personal computer, and the central processing unit 1 is a computer main body including a CPU, a ROM, and a RAM, and has a large capacity external storage (hard disk device, CD-ROM playback device, DVD-ROM). A music database 2 and a video database 3 are constructed in a playback device or the like. Also, a communication control device 4 that communicates with the karaoke host device via a subscriber telephone line or ISDN, a user interface device 5 that exchanges input information from the user and response information for the user, and MIDI data Generating device 6 for generating an acoustic signal of accompaniment music on the basis of music performance data mainly composed of music, an amplifying device 9 for amplifying the accompaniment music and the audio signal from microphone 7 and outputting them to speaker 8, and CRT or LCD Alternatively, a video display device 10 using a PDP or the like and an image processing device 11 that processes image data to be displayed on the video display device 10 are provided.

=== Dynamic howling suppression circuit ===
FIG. 2 shows a schematic configuration of the amplifying device 8 in FIG. The amplification device 8 includes a mixing amplifier 12 that mixes and amplifies the audio signal from the music generation device 6 and the audio signal from the microphone 7, the dynamic filter circuit 13 through which the output signal of the mixing amplifier 12 passes, and the output of the filter circuit 13. Power amplifier 14 for further amplifying, howling detection circuit 15 for detecting howling while measuring the frequency spectrum of the audio signal transmitted to this system, and dynamic filter circuit 13 receiving the detection signal of howling detection circuit 15 And a filter control circuit 16 for controlling the characteristics of the filter. The dynamic filter circuit 13, the howling detection circuit 15 and the filter control circuit 16 are the main elements of the above-described dynamic howling suppression circuit.

  The filter control circuit 16 receives and controls the control signal from the central processing unit 1 and controls whether the howling canceller is valid / invalid. When the howling canceller is disabled, the filter control circuit 16 keeps the frequency characteristics of the dynamic filter circuit 13 flat.

When the howling canceller is set to be effective, the filter control circuit 16 controls the characteristics of the dynamic filter circuit 13 in response to the output signal of the howling detection circuit 15 as follows.
(A) When detecting howling, the howling detection circuit 15 transmits information on the frequency (howling frequency) causing howling to the filter control circuit 16.
(B) Upon receiving a signal conveying the howling frequency, the filter control circuit 16 controls the dynamic filter circuit 13 to set the attenuation level of the howling frequency band to the maximum (−20 dB) and maintain the state for a certain time ( 3 seconds).
(C) When 3 seconds elapse, the filter control circuit 16 gradually decreases the attenuation level of the dynamic filter circuit 13 and finally returns to the original flat characteristic. The rate of change at this time is, for example, 2 dB per second.
(D) The above series of operations is repeated each time the howling detection circuit 15 detects howling.
(E) The filter control circuit 16 transmits the control information of the dynamic filter circuit 13 (data expressing which frequency band is attenuated at what level) to the central processing unit 1.

=== Enable / Disable setting and canceller status display ===
In any of the karaoke performance period and the performance suspension period, when a specific operation input is made on the user interface device 5, the central processing unit 1 responds to this and generates data of a canceller setting screen as illustrated in FIG. Then, the image is supplied to the image processing apparatus 11 and displayed on the video display apparatus 10. During karaoke performance, the canceller setting screen is displayed so as not to overlap with the display of lyrics subtitles.

  On the canceller setting screen, whether the current status is set to “valid” or “invalid” is displayed, and operation guidance for setting switching between “valid” and “invalid” is displayed. Further, a level meter is displayed on the canceller setting screen when the current state is set to “valid”, and the attenuation level of the dynamic filter circuit 13 described in (B) and (C) is sequentially displayed. In other words, if howling has not occurred, the level meter indicates the minimum value, and if howling occurs, the level meter indicates the maximum value, and the indicated value gradually decreases after 3 seconds. By looking at this, the effectiveness of the howling canceller can be confirmed visually. FIG. 4 shows another example of the canceller setting screen. In this example, when “valid” is set, the frequency characteristics of the dynamic filter circuit 13 are sequentially displayed. In this figure, four howling frequencies are simultaneously measured, and the state in which the attenuation level of each howling frequency is dynamically controlled in parallel is displayed in a graph. This is an interesting display for those who are somewhat technical but knowledgeable.

It is a schematic block diagram of the karaoke apparatus which concerns on one Example of this invention. It is a schematic block diagram of the amplifier 8 in an Example same as the above. It is the schematic which shows an example of a canceller setting screen. It is the schematic which shows the other example of a canceller setting screen.

Explanation of symbols

8 Amplifier 12 Mixing amplifier 13 Dynamic filter circuit 14 Power amplifier 15 Howling detection circuit 16 Filter control circuit

Claims (3)

A karaoke apparatus comprising a karaoke performance means, a dynamic howling suppression circuit, and a control means,
The karaoke performance means inputs the audio signal of the accompaniment music to the mixing amplifier and supplies the lyrics subtitle image to the display means.
The dynamic howling suppression circuit detects howling that has occurred in the mixing amplifier system, and in response to the detection operation, attenuates the gain of a specific frequency band as appropriate, and then gradually restores it to the original state.
The control means invalidates the dynamic howling suppression circuit when the canceller invalid setting is made by the user input, and effectively operates the dynamic howling suppression circuit when the canceller valid setting is made by the user input. Enable display processing,
The karaoke apparatus which displays the gain attenuation level by the dynamic howling suppression circuit on the display means in response to the user input. The karaoke apparatus according to claim 1, wherein the display process displays the frequency characteristics of the dynamic howling suppression circuit on a display unit. 3. The karaoke apparatus according to claim 1, wherein the display process displays a message for accepting a setting input for valid / invalid of the dynamic howling suppression circuit in accordance with the display unit.

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