JPH0344313B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is used in conjunction with an audio signal recording and reproducing device such as a karaoke machine, and compares the audio signal sung by a user with the audio signal reproduced from a standard magnetic tape or the like. This invention relates to a scoring device that automatically scores a user's singing ability.

Configuration of conventional examples and their problems As a field of audio equipment, when a performance signal from a musical instrument recorded on a recording medium such as a magnetic tape is reproduced and amplified, and a user sings along with it, the signal is mixed with the performance signal. There is something commonly called a ``karaoke device'' that amplifies the sound, and it is widely used.

A method called "audio multiplex tape" that is used in the above-mentioned "karaoke machine" and allows one person to study singing is rapidly becoming popular. As shown in FIG. 1, this audio multiplex tape is a magnetic tape 1 on which a vocal signal of a singer is recorded on a first track 101, and a performance signal of a musical instrument is recorded on a second track 102. When using this magnetic tape, an audio multiplexing type ``karaoke apparatus'' having the configuration shown in FIG.
02 and a second tape reproducing means 3 consisting of a magnetic head 301 and an amplifier 302, these two outputs are output from the microphone input means 4 consisting of a microphone 401 and an amplifier 402. At the same time, the mixing amplifier 5 mixes and amplifies the power, and outputs the signal from the speaker 6 as an acoustic signal.

It is said that you can improve your singing ability by listening to vocal signals recorded on a recording medium using the above device and practicing singing along with the vocal signals yourself, but no matter how much you practice, The drawback was that users could not tell how close their own singing was to the vocal signal of the model singer, or in other words, how much their own singing ability had improved. To solve this problem, the vocal signal recorded on the audio multiplexing recording medium and the user's singing voice signal are compared, and the degree of matching is calculated and displayed as a score, which can be used to evaluate the user's singing ability. There are performance devices on the market that come with a scoring device called a ``voice multiple scoring device'' or ``sound multiple scoring device'' that provides two objective evaluation means. The performance device to which this "multiple note scoring machine" is attached has a configuration as shown in Figure 3.
A first waveform converting means 7 for converting the output signal of the microphone input means 4 into a pulse signal or a digital signal, and a second waveform converting means for converting the output audio signal of the first magnetic tape reproducing means 2 into a pulse signal or a digital signal. The conversion means 8 computes and processes the output signals of the two waveform conversion means to determine how much the user's voice from the microphone input means 4 matches the vocal signal from the first magnetic tape reproduction means 2. A microcomputer 15 that evaluates the score using items such as changes in pitch and calculates the degree of matching as a score, and a score display means 1 that displays the score.
4 has been added.

It depends on how the three elements of a song, pitch, rhythm, and melody, are detected by the first and second waveform conversion means 7 and 8 of this "note scorer" and how they are specifically calculated by the microcomputer 15. This determined the scoring accuracy of this "Otona scoring machine." FIG. 4 shows an actual circuit example of the first waveform converting means 7. Normally, the first waveform converting means 7
Since the same circuit is often used for the first waveform converting means 7 and the second waveform converting means 8, the circuit of the first waveform converting means 7 will be representatively explained with reference to the operational diagram of FIG.

701 is an input terminal, 702, 704, 705,
708, 710, 711 are resistors, 703, 70
6 and 709 are capacitors, 707 is an operational amplifier (hereinafter abbreviated as OP amplifier), 712 is a transistor, and 713 is an output terminal.

OP amplifier 707 and resistors 702, 704, 7
05 and capacitors 703 and 706 constitute a low-pass active filter, and the input terminal 7
It removes the high-frequency components of the audio signal as shown in FIG. The high-frequency components that are not sufficiently removed by the active filter are auxiliary removed by the time constant circuit. The audio signal shown in FIG. 5b from which the high-frequency components have been removed by the necessary amount is converted into a pulse waveform as shown in FIG. 5c by resistors 710 and 711 and transistor 712. becomes. In this way, the first waveform converting means 7 converts the user's singing voice signal output from the microphone input means 4 into a pulse waveform. Similarly, the vocal signal output from the first magnetic tape reproducing means is also converted into a pulse waveform by the second waveform converting means 8.

According to the above waveform conversion means, the so-called fundamental waves of the user's singing voice signal and the vocal signal of the magnetic tape playback are respectively extracted and converted into pulse waveforms, and the microcomputer 15 performs a comparison operation on both pulses. The degree of matching was calculated as a score. Therefore, of the three elements of a song, only the pitch can be detected from the pulses, and other rhythms, melodies, etc. cannot be detected unless other waveform conversion means are used. In other words, although the frequency component of the fundamental wave of the audio signal can be detected from the pulse waveform, elements such as rhythm and strength are not included in the pulse, and the first and second waveform conversion means 7 and 8 alone cannot detect the frequency component of the fundamental wave of the audio signal. It had the disadvantage that highly accurate scoring was not possible.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
The strength of the user's singing voice signal is compared with the strength of the vocal signal recorded on the magnetic tape, and depending on the degree of match, the strength of the user's singing voice signal is determined. The purpose is to score users' singing ability and provide a more accurate scoring device.

Structure of the Invention A first rectifying means for rectifying the audio signal sung by the user, first and second integrating means for integrating the rectified voltage of the first integrating means, and output voltages of the first and second integrating means. A first strength detection device is configured by a first comparator that compares the sound signal, and the first strength detection device extracts a strength change corresponding to a gradual time change of the audio signal as a pulse signal.
a second rectifying means for rectifying the vocal signal recorded on the recording medium; third and fourth integrating means for integrating the rectified voltage of the second rectifying means; A second strength detection device is configured by a second comparator that compares the output of the fourth integrating means, and the second strength detection device detects strength changes corresponding to gradual time changes of the vocal signal into a pulse signal. The first and second time-series pulses are compared on the same time-series, and the audio signal sung by the user and the vocal signal recorded on the recording medium match or do not match. It is configured to determine the strength and weakness of the system.

DESCRIPTION OF THE EMBODIMENTS FIG. 6 is a block diagram of a "sound scoring machine" showing an embodiment of the present invention. FIG. 7 is a specific circuit diagram of the first strength detection device. The second strength detection device also uses the same circuit in many cases. FIG. 8 is an explanatory diagram of the operation of the first strength detection device.

In FIG. 6, reference numeral 10 denotes a second intensity detection device 9 for obtaining pulse signals corresponding to the intensity from the output audio signal of the magnetic tape reproducing means 2; and a second intensity detection device 9 for obtaining pulse signals corresponding to the intensity from the output signal of the microphone input means 4. This is the strength detection device of No. 1, and the others are the same as those shown in Fig. 3. The outputs of the first and second strength detection devices are input to the microcomputer 15, and in addition to the pitch evaluation, the degree to which the vocal signal from the magnetic tape playback means 2 and the user's voice are consistent with respect to strength is determined. The degree of non-conformity will be displayed as strength/weakness deduction points. Strength detection device 9, 1
0 uses the same circuit, the rhythm detection device 10 will be used as a representative, and its operation will be explained with reference to the circuit diagram in FIG. 7 and the operation explanatory diagram in FIG.

11 is a rectifier, 12 is two systems of integrating means with different time constants, 13 is a comparator, 17 to 23 are resistors, 24 to 27 are capacitors, 28 is a rectifying diode, 29 is an OP amplifier, 30 is a comparator, 31 is the input terminal for the vocal signal for magnetic tape playback, 32 is the strength detection output terminal, 33 is the positive power terminal, 34 is the negative power terminal, a in Fig. 8
is the actual input level of the vocal signal, b is the rectified output waveform of the rectifier circuit 11, c is the rectified voltage waveform input to the non-inverting input terminal of the comparator 30, and c is the rectified voltage waveform input to the inverting input terminal of the comparator 30. rectified voltage waveform, d is comparator 3
This is the strength detection output output from 0.

First, the vocal signal enters from the input terminal 31,
The rectifier circuit 11 rectifies the rectified output waveform b, and then the rectified output is passed through a time constant circuit consisting of a resistor 21 and a capacitor 27, and a resistor 2.
2. A time constant circuit composed of a capacitor 26 causes a difference due to time delay depending on the condition of τ ₁ = R ₂₁ C ₂₇ > τ ₂ = R ₂₂ C ₂₆ , and relatively time constants τ ₁ and τ ₂ Since both are set large, the waveform 3 will slowly follow large changes in the audio level.
5, 36, and are input to the input terminal and minus input terminal of the comparator 30. Therefore, c
In the shaded area, the voltage at the non-inverting input terminal of the comparator 30 is greater than that at the inverting input terminal, and a voltage of H is outputted, thereby obtaining a waveform d of the strength detection output. Usually, it is appropriate that τ ₁ be 2 to 3 seconds, and τ ₂ be 0.5 to 1.5 seconds. Comparing a and d in Figure 8, we see that the strength pulse rises faster than the rise of the audio level, and when the audio level is high, the pulse duration becomes longer, and conversely, when the audio level is low, the pulse duration becomes longer. It turns out that the width becomes shorter. Therefore, it is possible to detect the climax part and the part where the song is sung at a lower tone throughout the entire song, making it possible to realize so-called dynamic detection. Also, by setting R _{21 and} R ₂₂ so that R 21 ≫ R ₂₂ , a difference will occur due to the voltage drop of the bias current of the operational amplifier, and if a voltage drop difference that is sufficient to cancel the offset voltage and offset current is obtained. When there is no signal, the voltage of the inverting input terminal is always higher than that of the non-inverting input terminal, and the output of the operational amplifier can be uniquely set to L.

As described above, according to this embodiment, the strength components included in the vocal signal can be detected with a simpler configuration without using an AD converter or the like. Therefore, the intensity pulse train for the vocal signal recorded on the magnetic tape and the intensity pulse train for the audio signal sung by the user can be compared in time series, and the strength of the microphone signal can be determined according to the degree of matching.

However, when a user actually sings, it is difficult to sing exactly the same way as the vocal signal recorded on magnetic tape, and as the user becomes better at singing and sings with more emotion, the performance becomes more difficult. Since there is a tendency to sing with a slight delay, it is necessary to advance the gap in the rise of the strong and weak pulses and to tolerate the delay. The rise and fall of the strength pulse of the vocal signal recorded on the magnetic tape and the rise and fall of the strength pulse of the voice signal sung by the user are -T ₁ (=200ms) to +T ₂ (+
A deviation within a range of 300 ms) is allowed, and the degree of matching of the above-mentioned strong and weak pulse trains is compared in time series.

The total time of non-matching is Tn, the total time of comparing strong and weak pulse trains is Tt, and the number of points deducted due to the degree of non-matching is
When Pi is assumed and the number of penalty points for dynamics is P ₁ , the number of penalty points for dynamics is calculated as Pi=Tn/Tt×P ₁ .

Also, if you want to set the beginner and advanced levels,
The total number of strength/weakness deduction points P ₁ is variable.

In the present embodiment, a method of deducting points based on the degree of mismatch between strong and weak points has been described, but calculation may be performed using a scoring method based on the degree of match between strong and weak points.

Furthermore, although a magnetic tape is used as the recording medium in this embodiment, a magnetic disk or the like may also be used.

The method for determining the strength of the microphone signal will be explained using FIG. 9. A is a pulse indicating the presence or absence of a vocal signal recorded on the magnetic tape, and indicates L when there is no vocal signal and H when there is. b shows a strong/weak pulse train for a vocal signal recorded on the magnetic tape, and c shows a strong/weak pulse train for a voice signal sung by a user. t ₁ <T ₁ ,
When t ₂ > T ₂ , t ₃ > T ₁ , the delay t ₁ is allowed, and t ₂ , t ₃
is counted as the non-matching time, and the non-matching time Tn=
t ₂ +t ₃ , the total time of comparing the strong and weak pulses is Tt. For example, if Tn=10sec, Tt=50sec, and P ₁ =30 points, the strength/weakness deduction number Pi is Pi=Tn/TtPi=10/50×30=6 points.

In addition, when setting beginner and advanced levels, the total number of strength and weakness deduction points _P1 is made variable.

In the present embodiment, a method of deducting points based on the degree of mismatch between strong and weak points has been described, but calculation may be performed using a scoring method based on the degree of match between strong and weak points.

Effects of the Invention The first and second strength detection devices are introduced into the microphone signal system of the user's singing and the vocal signal system recorded on the magnetic tape, respectively, and the strength pulse trains are obtained as the outputs respectively, and based on a certain law, By performing comparative calculations, it is possible to determine how well the user's singing voice signal matches the vocal signal recorded on the magnetic tape in terms of strength, and it is possible to do so with a simple configuration without using an AD converter. , it is possible to provide a scoring device with higher accuracy.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of an audio multiplex track on a magnetic tape, Figure 2 is a block diagram of an audio multiplex ``karaoke device,'' and Figure 3 is a block diagram of a conventional ``audio multiplex scoring device.'' , FIG. 4 is a circuit diagram showing a specific configuration of the first waveform converting means in FIG. 3,
FIG. 5 is an operation explanatory diagram for explaining the operation of the first waveform conversion means, FIG. 6 is a block diagram of an embodiment of the present invention, FIG. 7 is a circuit diagram of the main part, and FIG. FIG. 9 is a waveform diagram showing a strong and weak pulse train for a vocal signal recorded on a magnetic tape and a strong and weak pulse train for a voice signal sung by a user. 2...first magnetic tape reproducing means, 3...second
magnetic tape reproducing means, 4... microphone input means,
7...First waveform conversion means, 8...Second waveform conversion means, 9...First strength detection device, 10...Second strength detection device.

Claims (1)

[Claims] 1. A first rectifying means that rectifies an audio signal sung by a user, and a first integrating means and a second integrating means that integrate the rectified voltage of the first rectifying means and have different time constants. and a first comparator that compares the output voltages of the first integrating means and the second integrating means, and a first comparator that extracts a change in strength corresponding to a gradual time change of the audio signal as a first pulse signal. a second rectifying means for rectifying the vocal signal recorded on the recording medium, a third integrating means and a fourth integrating means for integrating the rectified voltage of the second rectifying means and having different time constants. an integral means of
a second strength detection device that extracts strength changes corresponding to gradual time changes of the vocal signal as a second pulse signal by a second comparator that compares the outputs of the third integration means and the fourth integration means; , comparing the first pulse and the second pulse;
A scoring device characterized in that it is configured to determine whether an audio signal sung by a user and a vocal signal recorded on a recording medium match or do not match. 2 The time constants of the first integrating means and the third integrating means are set to at least 0.5 seconds or more and to approximately the same value, and the time constants of the second integrating means and the fourth integrating means are set to at least 0.5 seconds. The scoring device according to claim 1, characterized in that the above values are set to substantially the same value.