JPS5927966B2 - karaoke player - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that converts a music signal recorded on a record, tape, or the like into a signal called karaoke in which a vocal signal is attenuated or removed and reproduces the signal.

The present inventor has developed a device that attenuates an audio signal from a music signal, mixes it with another audio signal, and reproduces the sound signal.

This device attenuates the singer's vocal signal included in the music signal, and mixes the audio signal separately from this to mask the vocal signal, making the singer's singing voice inaudible. That is, in reality, the vocal signal is simply attenuated and reproduced, but this is masked by another mixed audio signal, making it inaudible. This effectively utilizes the masking effect, which is a characteristic of the human ear. What is masking effect?
This is a phenomenon in which when sound A of a certain frequency is being played and sound B, which is louder than sound A, is played, the sensitivity of the ears is reduced by sound B, making it impossible to hear sound A at all. Figure 1 shows how much a 200H2b disturbance sound with a sensory level of 90 dB masks the purity of a given frequency.
As you can see from this figure, the pure tone of 200Hz is 60dB
A pure tone of 300 Hz is masked and becomes inaudible below approximately 20 dB (70 dB lower than the interfering sound).

This figure shows that sounds close to interfering sounds are most effectively masked. By the way, the playback device invented earlier by the present inventor masks the singer's voice recorded on a record or tape with his own singing voice by singing along with the music signal. When the singing voice of the singer deviates considerably from the recorded voice of the singer, the singer's voice is not sufficiently masked and can be heard to some extent.

In order to further eliminate this drawback, the present invention attenuates or eliminates the audio signal contained in the music signal, and generates and mixes a scale signal that is the same or almost the same as the audio signal into the signal of 9. This invention is configured to most effectively mask the singer's singing voice using a scale signal, and an important purpose of the present invention is to mask a singer's singing voice most effectively when a record or tape on which vocals are recorded is played back in the same way as a karaoke record. ,
An object of the present invention is to provide a karaoke playback device in which a singer's attenuated voice is more effectively masked.

An embodiment of the present invention will be described below based on the drawings.

The karaoke performance device shown in FIG. 2 includes attenuation means 1 for attenuating or removing an audio signal from a music signal, a detection means 2 for detecting an audio signal from this music signal, and an audio signal detected by this detection means 2. The apparatus includes a scale signal generating means for generating a scale signal having at least the same frequency, and a mixing means for mixing the scale signal generated by the generating means with a music signal from which an audio signal has been attenuated or removed.

The attenuation means 1 shown in FIG. 2 consists of two sets of bandpass filters 5, a phase inversion circuit 6, and an addition circuit 7. The bandpass filter 5 has a passband through which human voice signals can pass, for example, a passband of 100 to 400 Hz, and only the signals that have passed through the bandpass filter 5 are added after phase inversion and are attenuated. Therefore, signals that do not pass through the bandpass filter 5, such as low frequency music signals of 100 Hz or less, are reproduced without being attenuated. The audio signal output from the bandpass filter 5 is converted into an opposite phase by a phase inversion circuit 6, and this is added by an adder circuit 7 to attenuate the audio signals recorded in the left and right channels at the same phase and level.

The detection means 2 detects the audio frequency band, for example, 80 to 400Hz.
two sets of bandpass filters 8 that pass the frequencies of;
Adding circuit 9 that adds the outputs of this bandpass filter 8
By selecting the audio signals included in the left and right channels with the bandpass filter 8 and adding these, the audio signals included in both channels are detected and the audio recorded at the same phase and the same level is detected. Raise the signal level higher than other music signals.

The scale signal generating means 3 includes a scale detection circuit 10, a switching circuit 12, and an oscillation circuit 11.

The detection circuit 10 detects the frequency of the microphone input signal, that is, the musical scale. In FIG. 2, a plurality of bandpass filters 13 are connected in parallel, and each bandpass filter 13 detects the microphone input signal. One octave is divided into 7 tones or 12 semitones so that the frequency components contained in the 1 octave can be separated into major scales or chromatic scales.

Therefore, when separating the microphone input signal into a seven-tone scale, seven bandpass filters 5 are required for each octave.
When separating into 12 chromatic scales, 12 sets are required. The center frequency of a bandpass filter is determined to be equal to the frequency of each scale, but its passband width is attenuated by several DB or more at the overlap between adjacent bandpass filters, as shown in Figure 3. It is better to do so. The detection circuit 10 is
Since any circuit that can detect the scale, that is, the frequency component of the microphone input signal can be used, it is also possible to use a digital counter that is already used as a frequency counter.

It is preferable to input a signal with little level fluctuation to the detection circuit.

Therefore, an automatic gain control circuit 14 is provided before the detection circuit 10.
When the input level is low, it is greatly amplified, and when it is high, the amplification degree is lowered to reduce level fluctuations in the microphone input signal. In principle, the oscillation circuit 11 oscillates a signal having the same frequency as the musical scale detected by the detection means.

However, even if the singer's scale deviates somewhat from the standard scale, the oscillation frequency should be determined to be the frequency of the standard scale, so that the oscillation frequency will oscillate exactly at the frequency of the standard scale. . Therefore, the oscillation frequency is, for example, a geometric series with a common ratio of 1.05946 for a semitone and 1.12245 for a whole tone, that is, the C note is 261.63Hz. D sound 293
．． 66Hz. E sound 329.63Hz. F sound 349.23
Hz. G sound 392,00Hz... C1 sound, which is one octave higher than C sound, is determined to be 523.25Hz.
The oscillation frequency of the oscillation circuit 11 shown in FIG. 2 is controlled by a switching circuit 12, and the switching circuit 12 also oscillates a signal at a specific frequency.

That is, for example, when the bandpass filter 13C that detects the C sound in FIG. A signal with a frequency corresponding to, for example, 261.63 Hz is oscillated.

The oscillation circuit shown in Figure 2 is one that oscillates a signal of a single frequency, but even in multiple sets of oscillation circuits, like a conventional electronic organ circuit, it is possible to mix several frequency components into the fundamental wave. is possible. In this case, one switching circuit controls multiple sets of oscillation circuits. By the way, the second
As shown in the figure, an automatic volume adjustment circuit 15 is connected to the output side of the oscillation circuit 11, and this automatic volume adjustment circuit 15 is controlled by level fluctuations of the music signal, and outputs a large scale signal when a large input is applied. It is also possible to configure it as follows.

In the mixing means, two resistors R are connected in series to the signal paths of the left and right channels, and the output of the generating means is connected between the resistors R, so that scale signals are mixed to both the left and right channels. The mixing means of FIG. 2 further includes a mixing circuit for a separate input microphone input signal, and the microphone input signal is applied to the midpoint of a resistor R connected in series to the left and right channel signal paths for mixing. . In this way, devices equipped with a microphone input mixing circuit allow you to sing into the microphone along with the music being played.
Your singing voice will be mixed into karaoke and played back.

In the present invention, the attenuation means is not limited to that shown in FIG. 2, but it is also possible to use, for example, a band-elimination filter or a low-pass filter that attenuates the frequency of the audio signal frequency band and is connected in series with the signal path.

Further, as shown in FIG. 2, the detection means can detect only one channel without taking out both the left and right channels, or even in the case of monaural, using a band pass filter.

The scale signal generating means in FIG. 2 oscillates with an electrical signal of the reference scale closest to the input audio signal.
This generation means can also be used to convert the output waveform from the detection means, for example, into a sine wave of only the fundamental wave, and then mix harmonics with this to convert the waveform into a sound that is completely different from the input signal. According to this method, the frequency of the fundamental wave of the scale signal generated by the generating means is the same as the output signal of the detecting means, so that the most effective masking effect is expected.

Waveform conversion involves removing harmonics from the output signal of the detection means using, for example, a multi-stage RC low-pass filter to obtain only the fundamental wave, and then adjusting the output signal within a predetermined level range using a clipper, slicer, Schmitt trigger circuit, etc. It is best to convert it into a rectangular wave, oscillate the harmonics of this waveform, and mix them.

As described above, the karaoke playback device of the present invention attenuates the audio signal included in the music signal, detects this audio signal, and generates and mixes a scale signal with the same or almost the same frequency as the audio signal. It is configured. For this reason, the scale signal approaches the frequency of the attenuated audio signal very effectively, masking the attenuated audio signal extremely effectively, and the audio signal cannot be heard from the played music signal, making the ordinary record a karaoke state. There is an effect played by

[Brief explanation of the drawing]

FIG. 1 is a graph showing the masking effect, and FIG. 2 is a block diagram of a karaoke playback device showing an embodiment of the present invention.
FIG. 3 is a frequency characteristic graph of the bandpass filter of the generating means. 1...Attenuation means, 2...Detection means, 3
・・・－・・・Generation means. ．． 4...Mixing means, 5...Band pass filter, 6...
・Phase inversion circuit, 7... Addition circuit, 8...-
...Band pass filter, 9...Addition circuit, 1
0-...detection circuit, 11...-oscillation circuit,
12-... Switching circuit, 13...
Band-pass filter, 14--.. oscillation gain control circuit, 15.--. .. oscillation volume adjustment circuit.

Claims (1)

[Claims] 1. Attenuation means for attenuating or removing an audio signal from a music signal; and detection means for detecting an audio signal from this music signal;
A scale signal generating means for generating an electric signal having the same or almost the same frequency as the audio signal detected by the detecting means, and a music signal from which the audio signal is attenuated or removed from the scale signal generated by the generating means. A karaoke playback device comprising a mixing means for mixing the karaoke. 2. Claim 1, wherein the attenuation means is a band elimination filter that attenuates frequencies in the audio frequency band.
The karaoke playback device described in Section 1. 3. The karaoke playback device according to claim 1, wherein the music signal is stereo, and the attenuation means takes the difference component between the left and right channels to attenuate or remove the audio signal. 4. The karaoke playback device according to claim 1, wherein the detection means is a bandpass filter, and the passband of the bandpass filter is an audio frequency band. 5. The karaoke playback device according to claim 4, wherein the music signal is stereo, and the detection means takes the sum signal of the left and right channel signals and detects the audio signal with a band pass filter. 6. The karaoke playback device according to claim 1, wherein the scale signal generation means includes a reference scale oscillation circuit. 7. The karaoke playback device according to claim 1, wherein the scale signal generation means includes a waveform conversion circuit for the audio signal detected by the detection means. 8. The karaoke playback device according to claim 1, wherein the mixing means mixes the scale signal and a microphone input signal input separately from the scale signal.