JPH06153300A - Stereo signal processing unit - Google Patents

Abstract

PURPOSE:To facilitate a practice by extracting a vocal signal and a performance signal in a stereo signal after delaying the performance signal, synthesizing the delayed signal with an input audio signal, and outputting the synthesized signal so as to prevent the mixing between the vocal signal and a voice signal of a trainee. CONSTITUTION:Input stereo signals a, b are fed to an in-phase signal extract circuit 66 and an in-phase signal elimination circuit 43. Operational amplifiers 49, 50 of the circuit 43 eliminate the in-phase and same amplitude vocal signal from the stereo signals a, b and operational amplifiers 51, 52 extract left right performance, signals L, R and they are fed to the circuit 66 and delay circuits 53, 54. The vocal signal is extracted from the signals a, b at the circuit 66 and they are synthesized and the resulting signal is fed to an earphone 71. On the other hand, The performance signal delayed by the circuits 53, 54 is outputted via speakers SP1, SP2. As a result, the trainee listens to the vocal signal slightly earlier than the performance signal and the voice signal synthesized with the delayed performance signal is obtained by allowing the trainee to sing a song by using the vocal signal as a model.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a music source containing vocals, such as a CD (compact disc).
The present invention relates to a stereo signal processing device used in a so-called karaoke practice device that removes vocals from a cassette tape and mixes and outputs sounds input from a microphone.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional stereo signal processing apparatus. The L channel and R channel stereo signals including vocals are supplied to the L channel input terminal 1 and the R channel input terminal 2. These input terminals 1 and 2
To the amplifiers 5 and 6 via the volumes 3 and 4, respectively.
Are connected, and the stereo signals of the L channel and the R channel are amplified by the amplifiers 5 and 6 and output from the output terminals 7 and 8 to a speaker (not shown). An audio signal from the microphone input from the microphone input terminal 9 is amplified by the amplifier 10 and is connected in series between the input terminals 1 and 2 via the volume 11.
It is supplied to the connection points of 2, 13. Therefore, the audio signal input from the microphone input terminal 9 is combined with the stereo signal supplied to the L channel input terminal 1 and the R channel input terminal 2 and output.

FIG. 4 shows another conventional stereo signal processing apparatus, which is a so-called voice that removes a vocal signal from an input music source, synthesizes an audio signal input from a microphone and outputs the synthesized signal. This is a device called a changer. That is, L including the vocal signal
Channel and R channel stereo signals are supplied to the L channel input terminal 21 and the R channel input terminal 22. The stereo signals supplied to the L-channel input terminal 21 and the R-channel input terminal 22 are respectively supplied to the in-phase signal extraction circuit 23 and the operational amplifier 2
It is supplied to the non-inverting input terminals of 4, 25. The in-phase and in-amplitude vocal signals extracted by the in-phase signal extraction circuit 23 are supplied to the inverting input terminals of the operational amplifiers 24 and 25. Therefore, from the output terminals of the operational amplifiers 24 and 25, only the performance signal from which the vocal signal has been removed from the L channel and R channel stereo signals is output. These performance signals are output to the volume 26, 27, amplifier 28,
Output from the output terminals 30 and 31 via 29 to a speaker (not shown). The audio signal from the microphone input through the microphone input terminal 32 is amplified by the amplifier 33, and is output through the volume 34 by the operational amplifier 2.
Resistors 35, 3 connected in series between the output terminals of 4, 25
6 connection points. Therefore, the audio signal input from the microphone input terminal 32 is combined with the performance signal from which the vocal signal has been removed and output.

[0004]

By the way, in the case of the conventional apparatus shown in FIG. 3, the voice signal input from the microphone 7 is synthesized without removing the vocal signal included in the music source. Therefore, since the vocals included in the music source and the practitioner's voice are mixed and output, it is difficult for the practitioner to clearly distinguish his / her voice from the vocal of the music source, which is difficult to practice. It was

Further, in the case of the conventional apparatus shown in FIG. 4, the vocal signal contained in the music source is removed and the voice signal inputted from the microphone is synthesized. Therefore, the practitioner can clearly distinguish his voice from the vocal of the music source. However, in this case, it is difficult to practice because the model vocals included in the music source cannot be heard.

The present invention is to solve the problem of the above-mentioned conventional device, and the object thereof is to be able to listen to a model vocal included in a music source, and to include it in the music source. It is an object of the present invention to provide a stereo signal processing device in which vocals and practitioners' voices are not mixed and training is easy.

[0007]

In order to solve the above-mentioned problems, the present invention separates the in-phase and same-amplitude signals contained in a stereo signal from other signals, and the separating means. A first output means for outputting signals of the same phase and the same amplitude; a delay means for delaying signals separated by the separation means other than the same phase and the same amplitude for a predetermined time; and an input means for inputting an audio signal, A second method for synthesizing and outputting a signal other than the same phase and the same amplitude delayed by the delay means and the audio signal input by the input means.
And the output means of.

Further, the first extraction means for extracting a performance signal from a stereo signal including a vocal signal of the same phase and the same amplitude and a performance signal other than that, and the performance extracted from the stereo signal by the first extraction means. Second extraction means for extracting the vocal signal by subtracting the signal, first output means for outputting the vocal signal extracted by the second extraction means, and extraction by the first extraction means Second means for synthesizing the performance signal delayed by the delay means and the sound signal input by the input means, and outputting the synthesized performance signal delayed by a predetermined time And means. Further, the first output means is composed of an earphone. Also, the first output means is composed of a transmitter that transmits the extracted signal. Further, the first extracting means has a filter that passes a signal in the audio signal band included in the stereo signal.

[0009]

That is, according to the present invention, the vocal signal of the same phase and the same amplitude included in the stereo signal and the performance signal are extracted, the vocal signal is output from the first output means, and the performance signal is output by the delay means. After delaying for a predetermined time, it is combined with the audio signal input from the input means and output from the second output means. Therefore, since the practitioner can hear the vocal signal included in the stereo signal before the performance, the practitioner can easily sing. Further, according to the present invention, since the vocal can be heard by the earphone, only the vocal can be reliably heard. Further, since the vocal signal can be sent wirelessly by transmitting the vocal signal by the transmitter, it is easier to use than the earphone.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, L channel and R channel stereo signals including vocal signals are supplied to an L channel input terminal 41 and an R channel input terminal 42. The stereo signals supplied to the L-channel input terminal 41 and the R-channel input terminal 42 are respectively supplied to the common-mode signal removing circuit (first extracting means) 43. In this common mode signal removal circuit 43, a band pass filter (BPF) 4
Reference numerals 4 and 45 are connected to the L channel input terminal 41 and the R channel input terminal 42, respectively. These band pass filters 44 and 45 have a band that passes an audio signal of 200 Hz to 2 kHz, for example. This band pass filter 44
Is connected to the non-inverting input terminal of the operational amplifier 46,
The output end of the bandpass filter 45 is connected to the inverter circuit 47.
Is connected to the inverting input terminal of the operational amplifier 46 via. The output terminal of the operational amplifier 46 is connected to the operational amplifier 4 via an attenuator (1 / 2ATT) 48 that attenuates the signal amplitude to 1/2.
9 and 50 are connected to the inverting input terminal and the non-inverting input terminal, respectively. Non-inverting input terminals and inverting input terminals of these operational amplifiers 49 and 50 are connected to the L channel input terminal 41 and the R channel input terminal 42, respectively. The output terminal of the operational amplifier 49 is connected to the non-inverting input terminal of the operational amplifier 51 and the inverting input terminal of the operational amplifier 52. Furthermore, the operational amplifier 50
The output terminal of is connected to the inverting input terminal of the operational amplifier 51 and is also connected to the non-inverting input terminal of the operational amplifier 52.

Delay circuits (DLY) 53 and 54 are connected to the output terminals of these operational amplifiers 51 and 52, respectively. The delay circuits 53 and 54 are, for example, BBD (bucket bri
gadedevice), CCD (charge coupled device), or
It is composed of DRAM (dynamic random access memory), and it is possible to arbitrarily change the delay amount by changing the signal write timing and the signal read timing. When using DRAM, an A / D converter that converts the analog signal written to DRAM into a digital signal,
And a D / A converter for converting a digital signal read from the DRAM into an analog signal. The performance signal from which the in-phase and in-amplitude vocal signals have been removed by the in-phase signal removing circuit 43 is output by the delay circuits 53 and 54.
For example, 100 ms to 1 s is delayed. These delay circuits 53 and 5
Volumes 55 and 56, amplifiers 57 and 5 are provided at the output end of
Output terminals 59 and 60 are connected to each other via 8, and speakers SP1 and SP2 are connected to the output terminals 59 and 60.

A microphone input terminal 61, to which a voice signal from a microphone (not shown) is supplied, has resistors 64 and 65 connected in series between the delay circuits 53 and 54 via an amplifier 62 and a volume 63. It is connected to the connection point.

On the other hand, the output terminals of the operational amplifiers 51 and 52 forming the common-mode signal removing circuit 43 are connected to the operational amplifiers 67 and 6 forming a common-mode signal extracting circuit (second extracting means) 66.
8 is connected to the inverting input terminal. These operational amplifiers 6
The non-inverting input terminals of 7, 68 are connected to the L channel input terminal 41 and the R channel input terminal 42, respectively. The output terminal of the operational amplifier 67 is connected to the non-inverting input terminal of the operational amplifier 69, and the output terminal of the operational amplifier 68 is connected to the inverting input terminal of the operational amplifier 69 via the inverter circuit 70. An earphone 71, for example, is connected to the output terminal of the operational amplifier 69.

The operation of the above configuration will be described. When the stereo signals a = V + L and b = V + R including the in-phase and in-amplitude vocal signals V are supplied to the L-channel input terminal 41 and the R-channel input terminal 42, these stereo signals are supplied to the in-phase signal removal circuit 43. To be done. In the in-phase signal removing circuit 43, first, a signal in the audio frequency band is extracted from the stereo signal by the band pass filters 44 and 45, and the extracted signal is combined by the operational amplifier 46. The amplitude of the combined signal is attenuated to 1/2 by the attenuator 48. This attenuator 48
Output signal c = V + (L + R) / 2 of the stereo signal a
= V + L and b = V + R are supplied to the operational amplifiers 49 and 50, respectively, which remove the vocal signal V having the same phase and the same amplitude from the stereo signals a and b. The output signals d = (LR) / 2 and e = (RL) / 2 of the operational amplifiers 49 and 50 are supplied to the operational amplifiers 51 and 52, and these operational amplifiers 5 and 5 are supplied.
At 1, 52, left and right performance signals are extracted. The output signals f = L and g = R of the operational amplifiers 51 and 52 are operational amplifiers 67 and 6 that form a common-mode signal extraction circuit 66 to which stereo signals a = V + L and b = V + R are supplied.
8, and the operational amplifiers 67 and 68 extract the vocal signal V from the stereo signals a and b. These extracted vocal signals V are the operational amplifier 6
The vocal signal h = V, which is combined by 9 and output from the operational amplifier 69, is supplied to the earphone 71 mounted on the ear of the practitioner.

On the other hand, the performance signals L and R from which the vocal signals have been removed by the operational amplifiers 51 and 52 constituting the in-phase signal removal circuit 43 are delayed by delay circuits 53 and 54 respectively for a predetermined time, and then the amplifier 57. , 58, and speakers SP1 and SP2. Therefore, the practitioner can hear the vocal signal slightly earlier than the performance signal, and when singing this vocal signal as an example,
This audio signal is combined with the performance signals L and R delayed by a predetermined time by the delay circuits 53 and 54 and output.

According to the above embodiment, vocals are extracted from the music source, and the extracted vocals are output earlier than the performance. Therefore, the practitioner can hear the modeled vocals slightly earlier than the performance, and by singing according to this vocal, the first sung song can be accurately sung and effective practice can be performed. Moreover, since the vocals are removed from the performance and the practitioner's singing voice and the vocals included in the music source are not mixed, it is possible to clearly distinguish one's own singing voice and to sing easily.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, instead of the earphone 71, for example, an FM transmitter 81 is provided at the output end of the operational amplifier 69, and the FM transmitter 81 transmits a vocal signal. This FM transmitter 8
The vocal signal transmitted by No. 1 is received by, for example, the FM radio receiver 82 arranged near the practitioner, and the practitioner can sing while listening to the vocal output from the FM radio receiver 82. With such a configuration, the model vocal can be heard wirelessly, which is easier to use.

The circuit of the present invention can be integrated into an integrated circuit except for the earphone and the speaker, and the earphone, the speaker and the like as the output means of the acoustic signal may be appropriately connected to the integrated circuit. The essence of the present invention is a circuit device that outputs vocals prior to playing, and earphones and speakers as output means can be changed as appropriate. Of course, various modifications can be made without departing from the scope of the invention.

[0020]

As described above in detail, according to the present invention, the model vocal included in the music source can be heard before the performance, and the vocal included in the music source and the practitioner's voice can be heard. It is possible to provide a stereo signal processing device that does not mix with each other and is easy to practice.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a main part, showing the present invention and a second embodiment.

FIG. 3 is a circuit configuration diagram showing a conventional stereo signal processing device.

FIG. 4 is a circuit configuration diagram showing a conventional stereo signal processing device different from FIG.

[Explanation of symbols]

41 ... L channel input terminal, 42 ... R channel input terminal, 43 ... In-phase signal removing circuit (first extracting means), 4
4, 45 ... band pass filter, 53, 54 ... delay circuit,
61 ... Microphone input terminal, 66 ... In-phase signal extraction circuit (second
Extraction means), 71 ... earphones, 82 ... FM transmitter.

Claims (3)

[Claims] 1. A separation means for separating an in-phase and same-amplitude signal and a signal other than that included in a stereo signal, and a first output means for outputting the in-phase and same-amplitude signal separated by this separation means. A delay means for delaying a signal other than the in-phase and same-amplitude separated by the separating means for a predetermined time; an input means for inputting an audio signal; and an in-phase signal other than the same-amplitude delayed by the delay means and the signal A stereo signal processing device comprising: a second output means for synthesizing and outputting a sound signal input by the input means. 2. A first extraction means for extracting a performance signal from a stereo signal including a vocal signal having the same phase and the same amplitude and a performance signal other than that, and a performance extracted from the stereo signal by the first extraction means. Second extraction means for extracting the vocal signal by subtracting the signal, first output means for outputting the vocal signal extracted by the second extraction means, and first extraction means for extracting the vocal signal A delay means for delaying the performance signal for a predetermined time, an input means for inputting a voice signal, a performance signal delayed by the delay means and a voice signal input by the input means are combined and output.
A stereo signal processing device, comprising: 3. The stereo signal processing apparatus according to claim 2, wherein the first extracting means has a filter that passes a signal in an audio signal band included in a stereo signal.