JPH0438355B2 - - 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, a music signal played by a musical instrument recorded on a recording medium such as a magnetic tape is reproduced and amplified, and when a user sings along with it, the music is reproduced. Amplify the sound by mixing it with the signal. There is something commonly called a "karaoke machine",
It is widely used for general household or commercial use.

By singing using the above-mentioned "karaoke device," the user can gain joy and satisfaction, but in recent years, the number of people who want to improve their singing ability has increased, and the number of people who want to improve their singing ability has increased. Some people receive guidance from a singing teacher, but this is not possible for everyone, and one way to study singing on your own is to use an audio multiplexing method such as magnetic tape called ``audio multiplex tape.'' recording media are rapidly becoming popular. For example, in the case of a magnetic tape, this audio multiplexing recording medium is a first track 101 on a magnetic tape 1, as shown in FIG.
A vocal signal from a singer or the like is sent to the second track 1.
02, musical signals played by musical instruments, etc. are recorded. When using this magnetic tape, an audio multiplexing type ``karaoke apparatus'' having the configuration shown in FIG.
01 and an amplifier 202, and a second tape reproducing means 3 consisting of a magnetic head 301 and an amplifier 302,
These two outputs are mixed and power amplified by a mixing amplifier 5 together with the output of a microphone input means consisting of a microphone 401 and an amplifier 402, and outputted from a 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 many times you practice, Even though
The disadvantage is that the user does not know how close his/her singing style is to the model vocal signal singing style, that is, how much his or her singing ability has improved. Even if the user sings in a different way, the user may not be aware of it, and when practicing on his/her own, a limit naturally arises, and the user often loses interest and loses the desire to practice. It had the following drawback.

Purpose of the invention The present invention solves the above-mentioned conventional problems.
Compares the vocal signal recorded on an audio multiplex recording medium with the user's singing voice signal, calculates and displays the degree of match as a score, and provides an objective evaluation method for the user's singing ability. The purpose is to

Structure of the Invention The scoring device of the present invention includes a first scale change detection means for detecting a change in the pitch of a scale of a first audio signal to be input, and a change in pitch of a scale of a second audio signal to be input. a second scale change detection means for detecting the number of pitch changes in the scale of the first audio signal; a first counting storage means for counting and storing the number of pitch changes in the scale of the first audio signal; a second count storage means for counting and storing the number, a first pitch detection means for detecting the fundamental frequency of the first audio signal, and a second audio signal detection means for detecting the fundamental frequency of the second audio signal. means, level change detection means for detecting a change in signal level of the second audio signal, information stored in the first count storage means, and information stored in the second count storage means. The degree to which the first audio signal matches the second audio signal in scale change is calculated as a score _P1 , and the level change detection means calculates the level of the second audio signal. The fundamental frequency of the first audio signal, which is the output of the first pitch detection means, around the time when a change in the pitch was detected, and the fundamental frequency of the second audio signal, which is the output of the second pitch detection means, The degree to which the pitches of the first audio signal and the second audio signal match is calculated as a score P ₂ by comparing and calculating the fundamental frequency.
It is composed of a score calculation means for calculating a total score from P ₁ and the score P ₂ , and a score display means for displaying the score. With this structure, the voice signal sung by the user can be used as the first voice signal. By using the reproduced audio signal of the vocal signal recorded on the recording medium that serves as a song model as the second audio signal, it is possible to determine how well the audio signal sung by the user matches the reproduced audio signal of the vocal signal on the recording medium. The user can recognize the level of his or her singing ability compared to the vocal signal on the recording medium because the score is displayed as a score to see how well the user has achieved the singing ability.

DESCRIPTION OF THE EMBODIMENT FIG. 3 is a block diagram showing an embodiment of the present invention. 4 is a microphone input means for converting the user's singing voice into an electrical signal and amplifying it; 401 is a microphone; and 402 is an amplifier. 2 is a first magnetic tape reproducing means for reproducing a vocal signal recorded on an audio multiplexing recording medium; 201 is a magnetic head; and 202 is an amplifier. Reference numeral 7 denotes a first waveform converting means, which converts a voice signal sung by a user into a pulse signal. 8 is a second waveform conversion means that converts the vocal signal on the recording medium into a pulse signal. Reference numeral 9 denotes a first scale change detection means, which detects changes in the scale of the voice sung by the user. Reference numeral 10 denotes a second scale change detection means, which detects a change in the scale of the vocal signal. Reference numeral 11 denotes a first counting storage means, which counts and stores the number of changes in pitch of the pitch of the voice sung by the user. Reference numeral 12 denotes a second counting storage means, which counts and stores the number of times the vocal signal changes in pitch. Reference numeral 13 denotes a first pitch detection means, which detects the fundamental frequency of the voice sung by the user. 14 is a second pitch detection means for detecting the fundamental frequency of the vocal signal. Reference numeral 15 denotes level change detection means, which detects level changes in the vocal signal. 16 is a score calculation means which compares and calculates the number of changes in the pitch of the voice sung by the user and the number of changes in the pitch of the vocal signal, and calculates how much the scale changes between the voice signal sung by the user and the vocal signal. In addition to calculating whether the signal level of the vocal signal changes as a score _P1 , the fundamental frequency of the voice sung by the user around the time when the signal level of the vocal signal changes is compared with the fundamental frequency of the vocal signal, and the voice signal sung by the user is calculated. The degree to which the pitch matches the vocal signal is determined as a score _P2 , and a total score is determined from the score _P1 and the score _P2 . 1
Reference numeral 7 denotes a score display means, which displays the score in order to inform the user of the score calculated by the score calculation means 16.

FIG. 4 is a block diagram showing the specific configuration of this embodiment, which includes detecting scale changes in the voice sung by the user, counting and storing the number of changes, detecting pitches, detecting scale changes in the vocal signal, and storing counts and storing the number of changes. The microcomputer 18 realizes the functions of detecting pitches and calculating scores.

FIG. 5 shows an actual circuit example of the first waveform converting means 7. Normally, 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, which removes high-frequency components of the audio electrical signal as shown in Figure 6a input to the input terminal 701, and at the same time outputs the OP amplifier. Necessary signal amplification is performed by the amplifying action of 707, and furthermore, a time constant circuit composed of resistor 708 and capacitor 709 supplementally removes high-frequency components that are not sufficiently removed by the active filter. In this way, the audio electrical signal shown in FIG.
12, the pulse waveform is converted into a pulse waveform as shown in FIG. 6c. In this way, the first waveform converting means 7 converts the user's singing voice signal, which is the output of the microphone input means 4, into a pulse waveform, and the second waveform converting means 8 similarly converts the voice signal sung by the user into a pulse waveform. The vocal signal that is the output of is also converted into a pulse waveform. Further, the level change detection means 15 can be realized by comparing the current level and the previous level using an analog-to-digital converter or a sample-and-hold circuit using conventional analog technology and digital technology.

The operation of this embodiment will be explained below based on the flowchart shown in FIG. 7 which shows the main part of the processing operation of the microcomputer.

First, it is assumed that the power of the device is turned on and that the memory elements and the like inside the microcomputer 18 have also been initialized. The user's singing voice signal becomes an electric voice signal by the microphone input means 4,
The signal is amplified and converted into a pulse signal by the first waveform converting means 7, which is input to the microcomputer 18. In step 19, the time width of the input pulse is converted into a digital quantity. That is, by counting the "H" period of the pulse signal shown in FIG. 6c using the microcomputer's own clock signal, the time width of the input pulse can be converted into a digital quantity. In this way, the time width from t ₁ to t ₂ , the time width from t ₃ to t ₄ , and the time width from t ₅ to t ₆ in FIG.
Conversion is performed in the order of time width... Note that when this time width increases, it indicates that the scale has become lower, and when it decreases, it indicates that the scale has become higher.

Next, in step 20, it is determined whether the time width of the pulse signal has increased compared to the previous time width. In other words, in the _pulse signal waveform of _FIG . If this is the time of detection, it is determined whether the time width from t ₃ to t ₄ has increased compared to the time width from t ₁ to t ₂ , which is the data of the previous time width, and the time width is determined. If is increasing, step 22
_N11 , which indicates the number of times the scale of the user's audio signal has fallen low, is increased by 1, and if the time width has not increased, the process proceeds to step 21. In step 21, it is determined whether the time width of the pulse signal has decreased compared to the previous time width, and if the time width has decreased, step 24 indicates the number of times the scale of the user's audio signal has increased. _N13 is increased by 1, and if the time width has not decreased, the process proceeds to step 23, where _N12 , which indicates the number of times the scale of the user's audio signal does not change, is increased by 1.

Steps 19, 20, and 21 as described above realize the function of the first scale change detection means 9, and steps 22,
23 and 24 realize the function of the first count storage means 11.

On the other hand, a vocal signal recorded on a magnetic tape 1, which is an audio multiplexing recording medium, is reproduced by a first magnetic tape reproduction means 2, converted into a pulse signal by a second waveform conversion means 3, and then sent to a microcomputer 18. After converting the time width of the input pulse into a digital quantity in step 25,
Step 26 determines whether the time width has increased compared to the previous time width, and if the time width has increased, step 28 increments _N21 , which indicates the number of times the scale of the vocal signal has become lower, by 1. If the time width has not increased, proceed to step 27. In step 27, it is determined whether the time width of the pulse signal has decreased compared to the previous time width, and if the time width has decreased, step 30 determines _N23 , which indicates the number of times the scale of the vocal signal has increased. is increased by 1, and if the time width has not decreased, the process proceeds to step 29, where _N22 , which indicates the number of times the scale of the vocal signal does not change, is increased by 1.

As mentioned above, steps 25, 26, and 27 realize the function of the second scale change detection means 10, and steps 28,
29 and 30 realize the function of the second count storage means 12.

Next, in step 31, similarly to step 19, the time width of the pulse signal of the voice signal sung by the user is converted into a digital amount and stored. That is, by counting one cycle of the pulse signal shown in FIG. 6c using the clock signal of the microcomputer itself, the time width of the input pulse can be converted into a digital quantity. In this way, the time width from t ₁ to t ₃ , the time width from t ₃ to t ₅ , and the time width from t ₅ to t ₇ in FIG.
Conversion is performed in the order of time width... Note that this time width is the reciprocal of the fundamental frequency of the audio signal,
An increase indicates that the pitch has become lower, and a decrease indicates that the pitch has become higher.

Next, in step 32, the time width of the pulse signal of the vocal signal recorded on the magnetic tape is converted into a digital amount and stored.

As mentioned above, steps 31 and 32 are the first
The functions of the pitch detection means 13 and the second pitch detection means 14 are realized.

Next, the output signal of the level change detection means 15 is inputted to the microcomputer 18, and step 33
It is determined whether the signal level has increased or not, and if it has increased, the process proceeds to step 34. Here, two types of time widths, which are information on the fundamental frequencies of the two audio signals, are compared, and a judgment is made in step 35. If there is a match here, proceed to step 36, and add 1 to the number of matches N _E.
Add. On the other hand, if they do not match, the process proceeds to step 37, and 1 is added to the number of non-matches N _D.

Next, in step 38, it is determined whether it is time to start scoring. Information on a push button switch (not shown) that specifies the start of scoring may be used to determine when to start scoring, or information on the presence or absence of performance music signals stored on the magnetic tape 1 may be used. The scoring may be started when the performance music signal is detected and the performance music signal disappears. It is also possible to record an end signal indicating the end of the song in advance, and use the point in time when the end signal is detected or the point in time when the end of the magnetic tape is detected.

If it is not yet time to start grading, proceed to step 38.
Then, the process proceeds to step 19, and the pulse signal time width change data N ₁₁ , N ₁₂ , N ₁₃ , N ₂₁ , N ₂₂ ,
N ₂₃ data collection etc. will be carried out.

Then, when it comes time to start scoring, the process proceeds from step 38 to step 39, where the score is calculated. Step 39 has the function of score calculation means 16.

First, the scale change score _P1 will be explained. This score is calculated based on time width change data N ₁₁ , N ₁₂ , N ₁₃ , N ₂₁ ,
It is based on _N23 and is calculated to give a maximum of 30 points. An example of the formula for calculating the score is:
With α, β, and γ as constants, the score P ₁ is P ₁ = 30 × {N ₂₁ +N ₂₂ +N ₂₃ )−(α｜N ₁₁ −N ₂₁ ｜+β｜N
₁₂ −N ₂₂ |+γ|N ₁₃ −N ₂₃ |)}/(N ₂₁ +N ₂₂ +N ₂₃ ) and perform the calculation.

The score based on the above formula is N ₁₁ = N ₂₁・N ₁₂ =
When N ₂₂・N ₁₃ = N ₂₃ , the perfect score is 30 points. This is a case where the three items of change, change to a lower level, and unchanged are all the same number of times, that is, the change in the scale of the audio signal sung by the user is the same as the change in the scale of the vocal signal on magnetic tape 1. This means that you will receive a full score in some cases.

On the other hand, in the above calculation formula, N ₁₁ =0, N ₁₂ =0,
The constants α, β, and γ are determined so that the score is 0 when N ₁₃ =0. This is to ensure that the score becomes 0 when the user does not sing at all.

Next, the pitch score _P2 will be explained. This score is calculated based on N _E and N _D , which are the results of comparing the values of one cycle of the pulse signal created from the user's audio signal and the vocal signal of magnetic tape 1, and the maximum score is 70 points. Calculate so that As an example of a formula for calculating the score, the score P ₂ may be defined as P ₂ =70×N _E /(N _E +N _D ) and the calculation may be performed.

The score based on the above calculation formula is 70 points, which is a perfect score, when N _D = 0, which means that the pitch of the user's singing voice signal and the pitch of the vocal signal on the magnetic tape are different from each other due to the change in the level of the vocal signal. This means that they match each time they are compared.

Then, the scale change score P ₁ and the pitch score P ₂ are added to obtain a final score.

After completing the score calculation, proceed to step 40.
The score will be displayed.

Here, the pulse time width pitch of the two types of audio signals around the time when the signal level of the vocal signal increases, and the final score is calculated as the scale change score P ₁
The reason why it is expressed as the sum of the pitch score P2 and the pitch score _P2 will be explained.

FIG. 8 1 shows an example of a user's song input from a microphone, and FIG. 8 2 shows an example of a vocal signal of an audio multiplexed medium by a professional singer. As shown in Figure 8 b and e, amateur users are free to change the frequency and signal level within a single vocalization, which is called vibration or vibration, just like the vocal signal of a professional singer. It is often not possible to do so. Therefore, in the case shown in the example in Figure 8, if the frequencies of the user's song and the vocal signal are compared and scored one after another, these vibrations and The impact of this will be significant. For example, as shown after the 2G point of the signal level f of the audio signal in Figure 8, the frequency of the vocal signal by a professional singer changes greatly due to vibration, while the frequency of the user's song remains almost constant because no vibration is applied. , it happens that you only get a very low score in this part. These bumps and vibrations vary greatly from person to person, even among professional singers, and they do not occur in the same way every time, even for the same singer, so when scoring a song, consider this.
If you continuously compare and score things including vibration and vibration, the dispersion of the scoring results will become very large.

However, unless we also compare the sound and vibration areas, we cannot truly evaluate the quality of the songs. For this purpose, comparisons of vibrations and vibrations are made by comparing scale changes, but with fewer points. Based on this idea,
In this embodiment, a comprehensive evaluation is performed by assigning 70 points to the pitch score _P1 and 30 points to the scale change score _P2 .

As described above, according to the present embodiment, by using the audio signal sung by the user and the vocal signal from a magnetic tape, etc., the effect of noise and vibration around the point where the signal level of the vocal signal increases is reduced. In addition to comparing the fundamental frequency of the audio signal of the user's song with the fundamental frequency of the vocal signal to evaluate the degree of pitch matching, it also includes the parts affected by noise and vibration. By performing a comparative evaluation of scale changes and allocating fewer points for the comparative evaluation of scale changes, evaluations with less variation can be made, and those who are skilled can obtain high scores depending on their skill. As a result, the final score is close to the evaluation score when humans actually listen and evaluate with their ears, and more accurate scoring results can be obtained, providing an objective means of evaluating the user's singing ability. can.

In this example, the user's singing voice signal was used as the subject of scoring, and the vocal signal recorded on magnetic tape, which is an audio multiplexing recording medium, was used as the scoring standard. Any audio signal such as a sine wave signal or a person's voice may be used.

Furthermore, in this embodiment, a waveform conversion means using a low-pass active filter and a transistor was used to convert an audio signal into a pulse signal.
This may be accomplished by using a circuit that directly converts the audio signal waveform into a digital pulse signal using an analog-to-digital converter.

Furthermore, in this embodiment, the scale change detection means, pitch detection means, count storage means, etc. were implemented using a microcomputer, but it goes without saying that these may be implemented and used using conventional general-purpose logic circuits, etc. .

In addition, in this embodiment, a waveform conversion means and a scale change detection means are provided separately for processing the user's audio signal and vocal signal processing, but these are only one system, and the user's audio signal is processed in a time-sharing manner. , and vocal signal processing may be performed.

In addition, in this embodiment, the time width in the case of "H" of the pulse signal which is the output of the _waveform converting means is shown _{in FIG .} It detects everything such as width, changes in the higher direction of the audio signal scale, changes in the lower direction, and 3 that remain unchanged.
We are trying to detect changes in species, for example,
In Figure 6c, the time span from t ₁ to t ₃ is followed by t ₅ .
Changes in the time width may be detected one at a time, such as the time width of t ₇ , or during a fixed period that is sufficiently long compared to the time width of one cycle of the pulse signal that is the output of the waveform conversion means. Examine the time width of the period of the pulse signal that is the output of the waveform converting means for all pulses or for a part of the pulses, find the average time width, maximum time width, etc. per one pulse,
Changes in the scale and pitch of the audio signal may be detected based on changes in the average time width, etc.
Alternatively, only one or two of the three types of changes, ie, a change in the higher direction, a change in the lower direction, and no change, may be detected.

Effects of the Invention As described above, the present invention includes two waveform conversion means for converting two audio signals into pulse signals, and detects how the scales of the two audio signals change based on the outputs thereof. two scale change detection means,
two counting storage means for counting and storing the output;
two pitch detecting means for detecting information representing the fundamental frequencies of the two audio signals based on the outputs of the two waveform converting means; and a level change detecting means for detecting changes in the level of the audio signals that serve as standards for scoring. , by comparing and calculating three types of two-system information: the number of times it was detected that the scale shifted to a higher scale, the number of times it was detected that the scale shifted to a lower scale, and the number of times that it was detected as unchanged, which are stored in the two counting storage means. , find the degree of agreement between the scale changes of the two audio signals as a score P ₁ ,
In addition, by using the output of the level change detection means to compare and calculate the pulse time width (period) of the two audio signals, which is information on the fundamental frequency around the time when the signal level of the audio signal, which is the standard for scoring, changes. The degree of matching between the pitches of these two audio signals is determined as a score _P2 , and the final score can be accurately obtained by adding the score _P1 and the score _P2 .

This means that people who practice singing using audio multiplexed recording media can use the vocal signals recorded on the audio multiplexed recording media as a singing teacher to evaluate the singing ability of the singing teacher. This means that it is possible to provide an objective means of determining how many points a person has in terms of singing ability. In other words, for those who practice singing, the goal of practicing becomes clearer, and they become more motivated to practice by saying, for example, ``I'm going to sing this song and practice until I get a score of 80 or higher,'' and then try singing. If you don't get good points, think about why you don't get good points,
By looking for weaknesses in your own singing style, you can further improve your singing ability, which has great effects.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of an audio multiplex track on a magnetic tape, which is one type of audio multiplex recording medium, and Figure 2 is an illustration of a so-called audio multiplex track using magnetic tape, which is one type of audio multiplex recording medium. 3 is a block diagram of a main part of an embodiment of the present invention, FIG. 4 is a block diagram showing a specific configuration of this embodiment, and FIG. 5 is a block diagram of a karaoke device of this embodiment. FIG. 6 is an operation explanatory diagram for explaining the operation of the first waveform conversion means;
FIG. 7 is a flowchart showing the main part of the processing operation of the microcomputer of this embodiment, and FIG. 8 is an explanatory diagram of changes in the singing style for explaining temporal changes in the singing style in this embodiment. 7...First waveform conversion means, 8...Second waveform conversion means, 9...First scale change detection means, 10
...Second scale change detection means, 11...First count storage means, 12...Second count storage means, 13
...First pitch detection means, 14...Second pitch detection means, 15...Level change detection means, 16...
Score calculation means, 17...Score display means.

Claims (1)

[Claims] 1. A first waveform converting means that converts an input first audio signal into a pulse signal, and based on the output pulse signal of the first waveform converting means, the scale of the first audio signal is high. a first tone change detecting means for detecting whether the pitch has shifted to a higher level, a lower level, or no change; and a pulse signal output from the first waveform converting means. A first pitch detecting means for detecting a fundamental frequency of a signal, a second waveform converting means for converting an inputted second audio signal into a pulse signal, and an output pulse signal of the second waveform converting means. a second scale change detection means for detecting whether the scale of the second audio signal has shifted to a higher scale, shifted to a lower scale, or remains unchanged; and a second waveform conversion means. A second pitch detecting means detects the fundamental frequency of the second audio signal based on the output pulse signal, and a transition to a higher pitch is detected based on the output of the first pitch change detecting means. Based on the outputs of the first counting storage means for counting and storing the number of times of detection, the number of times of detecting a transition to a lower scale, and the number of times of detecting that there is no change, and the second scale change detection means. a second counting storage means for counting and storing the number of times a transition to a higher scale is detected, the number of times a transition to a lower scale is detected, and the number of times no change is detected;
a level change detection means for detecting a change in the signal level of the audio signal; and the number of times a shift to a higher scale was detected and the number of times a shift to a lower scale was detected, which are stored by the first count storage means. , 3 information of the number of times it was detected that there was no change, the number of times that a shift to a higher scale was detected, the number of times that a shift to a lower scale was detected, and the number of times that it was detected that there was no change, stored in the second count storage means. 3 information on the number of times the voice signal has been played is compared, and the degree to which the scale change matches the first audio signal and the second audio signal is calculated as a score P ₁ , and the level change detection means The first pitch is the output of the first pitch detecting means near the time when the level of the second audio signal is detected to have changed.
The fundamental frequency of the audio signal and the fundamental frequency of the second audio signal which is the output of the second pitch detecting means are compared and calculated to determine the pitch between the first audio signal and the second audio signal. The degree to which the scores match is calculated as a score P ₂ , and the score P ₁ and the score
P ₂ ; and a score calculation means for calculating a total score.