JPH07191678A - Musical sound synthesizing device - Google Patents

Abstract

PURPOSE:To synthesize a musical sound signal which include rich harmonics and is large in variation in harmonic constitution by mixing the output signals of a 1st and a 2nd loop means. CONSTITUTION:A loop circuit 16 performs resonant oscillation by itself on the basis of respective coefficients FL1, Df1, DN1, and LG1 by using the output signal of a multiplier 14 as excitation energy, and synthesizes and outputs a musical sound signal, and a loop circuit 17 performs resonant oscillation by itself on the basis of respective coefficients FL2, Df2, DN2, and LG2 by using the output signal of a multiplier 15 as excitation energy, and synthesizes and outputs a musical sound signal. The output signal of the loop circuit 16 is multiplied by a multiplier 29 by a coefficient OG1 and then inputted to a 1st input terminal of an adder 31 and the output signal of the loop circuit 17, on the other hand, is multiplied by a multiplier 30 by a coefficient OG2, and inputted to a 2nd input terminal of the adder 31, which adds the output signals of the multiplier 29 and 30 and outputs the result as a musical sound signal MS.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone synthesizing apparatus for synthesizing musical tones whose tone volume, tone color and the like change over time like natural musical instrument sounds.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a configuration example of a musical sound synthesizer used in a conventional electronic musical instrument. In this figure, the excitation signal generator 1 outputs an excitation signal having a predetermined waveform and supplies it to the first input terminal of the adder 2. The adder 2 is
The addition result is supplied to the tone color control filter 3. The timbre control filter 3 imparts a predetermined characteristic according to the timbre to the addition result of the adder 2 based on a coefficient relating to the timbre supplied from a control unit (not shown), and outputs the output signal from the all-pass filter (hereinafter, (Referred to as APF) 4.

The APF 4 changes the phase difference between the signal supplied from the tone color control filter 3 and its output signal in accordance with the signal frequency for a slight pitch adjustment, and slightly delays the phase difference. Supply. Delay 5
Is composed of a multi-stage shift register or the like, supplies the input signal to the multiplier 6 after delaying the input signal for a predetermined time. Multiplier 6
Supplies the output signal of the delay 5 with a positive multiplication coefficient and then supplies it to the second input terminal of the adder 2.

As a result, the excitation signal input from the first input terminal of the adder 2 repeats circulation in the loop circuit 7 including the adder 2, the tone color control filter 3, the APF 4, the delay 5 and the multiplier 6. Therefore, a musical tone signal according to the comb-shaped filtering characteristic of the loop circuit 7 is synthesized and taken out from any one of the loop circuits 7.

The musical sound synthesizer described above simulates a wind instrument, such as a flute or a trumpet, whose basic structure corresponds to a model whose both ends are open. Here, FIG. 10A shows a basic structure of a wind instrument such as a flute and a sound pressure distribution of a fundamental wave f of a sound produced by a resonance phenomenon based on the basic structure. As shown in FIGS. 10 (b) and 10 (c), the wind instrument having such a structure basically produces musical tones of integer overtones f, 2f, 3f, ....

[0006]

By the way, in the above-described conventional tone synthesizer, the basic harmonic overtone structure of the output tone signal is determined by the respective components 2 to 6 of the loop circuit 7. However, there is a drawback that only tone signals having a simple overtone structure can be synthesized. The present invention has been made under such a background, and an object of the present invention is to provide a musical tone synthesizing device which can synthesize a musical tone signal including abundant harmonic overtones and having a harmonic overtone structure which greatly changes with time. .

[0007]

A musical tone synthesizer according to the present invention provides an excitation signal generating means for generating an excitation signal having a predetermined waveform, a characteristic corresponding to a tone color to the excitation signal, and a predetermined first signal. A first loop means having a positive loop gain, which is time-delayed and repeatedly circulated, and a characteristic according to a tone color are given to the excitation signal, and the same or substantially an integer ratio relationship with the first delay time. A second loop means having a negative loop gain for a second time delay and cyclic cycling; a mixing for mixing the output signal of the first loop means with the output signal of the second loop means. And means.

[0008]

According to the above structure, the first loop means positively feeds back the excitation signal to synthesize a tone signal of fundamentally integer overtone with the loop delay time as a fundamental period. The second loop means negatively feeds back the excitation signal to synthesize a fundamentally odd overtone musical tone signal having a fundamental cycle of twice the loop delay time. Then, the mixing means mixes the output signal of the first loop means and the second output signal. As a result, a tone signal having a complex overtone structure is synthesized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing an embodiment of the present invention,
A basic idea for solving the above-mentioned problems will be described. FIG. 6 is a block diagram showing a configuration example of a musical tone synthesizer simulating a wind instrument corresponding to a model such as a clarinet or a saxophone whose basic structure has one end open and the other end closed. In this figure,
The same reference numerals are given to the portions corresponding to the respective portions in FIG. 9, and the description thereof will be omitted. The musical sound synthesizer shown in FIG. 6 is different from that shown in FIG. 9 in that the output signal of the delay 5 is multiplied by a negative multiplication coefficient instead of the multiplier 6 which multiplies the output signal of the delay 5 by a positive multiplication coefficient. The point is that a loop circuit 9 in which a multiplier 8 is newly provided is provided.

FIG. 7 (a) shows the basic structure of a wind instrument such as a clarinet and the sound pressure distribution of the fundamental wave f'of the sound produced by the resonance phenomenon based on the basic structure.
As shown in FIGS. 7B and 7C, the wind instrument having such a structure basically has odd harmonics f ′, 3f ′, 5
The musical tones f '... are pronounced. The basic vibration is 1/2 that in the case of positive feedback.

In the tone synthesizer shown in FIGS. 9 and 6, the total delay time of each loop circuit 7 and 9 is a simulation of the transmission delay of the air pressure wave in the pipe of each wind instrument. All delay times correspond to each pipe length. Therefore, making all the delay times of the loop circuits 7 and 9 the same in the tone synthesizer shown in FIGS. 9 and 6 corresponds to making the respective tube lengths of the respective wind instruments the same.

Therefore, assuming that the total delay time of each loop circuit is the same in the tone synthesizer shown in FIGS. 9 and 6, FIG.
As can be seen from FIG. 7 and FIG. 7, in the tone synthesizer shown in FIG. 9, the even harmonics 2f ′, 4f ′, 6f ′, ... Of the fundamental wave f ′ of the tone produced by the tone synthesizer shown in FIG. Will be pronounced. Here, when expressing the spectrum structure of each tone, the spectrum structure of the tone generated from the tone synthesizer shown in FIG. 6 is shown in FIG.
The spectrum structure of a musical sound produced by the musical sound synthesizer shown in FIG. 9 is shown in FIG.

Therefore, when a plurality of musical tones output from each of the musical tone synthesizers are mixed at an appropriate mixing ratio, the musical tone has a spectrum structure as shown in FIG. 8C and contains abundant overtones. Musical sounds can be synthesized. Furthermore, if these odd overtones and even overtones are mixed based on a coefficient that changes with time such as after-touch data, it is possible to synthesize a musical tone signal whose harmonic overtone structure changes greatly with time.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an electronic musical instrument to which a musical tone synthesizer according to an embodiment of the present invention is applied. In this figure, the performance operator 10 is composed of a keyboard or the like, and has pitch data KC, touch data TCH,
Outputs after-touch data AT etc. The tone color setting operation unit 11 is used by the performer to set various coefficients relating to tone color and the like. The control unit 12 controls each unit of the device based on various data supplied from the performance operation unit 10 and the tone color setting unit 11.

The excitation signal generator 13 receives the waveform designation data WAVE for designating the signal waveform to be generated, the key-on signal KON and the touch data TCH for designating the generation timing of the generated signal, which are respectively output from the controller 12. Then, an excitation signal containing a lot of harmonics (typically, a noise signal such as white noise) is output and supplied to the multipliers 14 and 15, respectively. The multipliers 14 and 15 multiply the excitation signals by the input gain multiplication coefficients IG ₁ and IG ₂ output from the control unit 12, respectively, and then supply them to the loop circuits 16 and 17, respectively.

The loop circuit 16 is composed of an adder 18, a tone color control filter 19, an APF 20, a delay 21 and a multiplier 22, as in the loop circuit 7 of the musical tone synthesizer shown in FIG. The loop circuit 16 uses the output signal of the multiplier 14 as excitation energy based on the coefficients FL ₁ , Df ₁ , DN ₁ and LG ₁ (all values are positive) output from the control unit 12, respectively. It excites resonance oscillation by itself, synthesizes a musical tone signal and outputs it.

On the other hand, the loop circuit 17 includes the adder 2
3, tone color control filter 24, APF 25, delay 2
6 and multipliers 27 and 28. The loop circuit 17 uses the output signal of the multiplier 15 as excitation energy based on the coefficients FL ₂ , Df ₂ , DN ₂ and LG ₂ (all values are positive) output from the control unit 12 as excitation energy. It excites resonance oscillation by itself, synthesizes a musical tone signal and outputs it. The multiplier 28 adds the value “−” to the coefficient LG _2.
1 "and the negative coefficient" -LG ₂ "is multiplied by the multiplier 27
Supply to. That is, the loop circuit 17 has the same configuration as the loop circuit 9 shown in FIG.

Further, the coefficient DN ₁ supplied to the delay 21 substantially corresponding to the total delay time of the loop circuit 16 and the coefficient DN ₂ supplied to the delay 26 substantially corresponding to the total delay time of the loop circuit 17 are: The values are almost the same. This is because in the loop circuit 16, as already described,
A tone signal having an integer overtone structure whose basic cycle is a delay time of one round of the loop circuit 16 is synthesized, and in the loop circuit 17, an odd harmonic overtone structure whose basic cycle is a double delay time of one round of the loop circuit 17 is synthesized. Since the tone signal of No. 2 is synthesized, the fundamental vibration of the loop circuit 16 becomes 2f 'when the fundamental vibration of the loop circuit 17 is f', and the even number overtone configuration with respect to the fundamental vibration f'of the loop circuit 17 is formed in the loop circuit 16. This is to synthesize the musical sound of.

The multipliers 29 and 30 output the tone signals output from the loop circuits 16 and 17, respectively, and output gain multiplication coefficients OG ₁ and OG ₂ output from the control unit 12, respectively (see FIGS. 4B and 4B). c)) and then supplies to the adder 31. The adder 31 adds the output signal of the multiplier 29 and the output signal of the multiplier 30 and outputs it as a musical tone signal MS. Here, one method of generating the output gain multiplication coefficients OG ₁ and OG ₂ will be described. First, as shown in FIG. 2, the output gain multiplication coefficient OG ₁ selects the type of waveform to be supplied by supplying the tone color data TC to the envelope generator (EG) 32 that generates an envelope signal of a predetermined waveform, The selected envelope signal is generated at the rising edge of the key-on signal shown in (a), and the adder 33 adds the after-touch data AT shown in FIG. 4 (d) to the envelope signal,
Further, at the same time when the key is turned off, it is attenuated at a predetermined key release rate to generate, for example, the waveform shown in FIG. The rising amplitude of the output gain multiplication coefficient OG _{1 at} the time of key-on corresponds to the size of the touch data TCH.

The output gain multiplication coefficient OG ₂ is shown in FIG.
In the example of (c), since the tone signal output from the loop circuit 17 is mainly used, the tone signal rises at the same time as the key-on, and is kept constant until the key-off occurs, and is attenuated at the predetermined key-release rate at the same time as the key-off. However, this output gain multiplication coefficient OG ₂ is similar to the output gain multiplication coefficient OG ₁ in FIG.
As shown in, the EG 34 generates an envelope signal having a waveform selected based on the tone color data TC at the rising edge of the key-on signal, the adder 35 adds the after-touch data AT to the envelope signal, and further, the key-off signal At the same time, it may be generated by being attenuated at a predetermined key release rate.

In such a structure, when the performer presses a key on the keyboard of the performance operator 10, for example, a key corresponding to the C tone, the pitch data KC corresponding to the key is pressed from the keyboard.
Key data such as is output. The touch input unit (not shown) detects the initial touch and aftertouch of the key corresponding to the C sound of the keyboard, generates touch data TCH indicating the strength of the touch, and outputs the touch data TCH together with the aftertouch data AT.

As a result, the control unit 12 causes the coefficients FL ₁ and FL ₂ , the coefficients Df ₁ and Df ₂ and the coefficient L for the pitch data KC and the touch data TCH corresponding to the C sound.
G ₁ and LG ₂ are output, and a value obtained by subtracting the above-described delay time of the APFs 20 and 25 from the total delay time of each loop circuit 16 and 17 corresponding to the C sound is used as a coefficient DN _{1 of the} delays 21 and 26. And DN ₂ and output as tone color control filters 19 and 24, APF2
0 and 25, multipliers 22 and 27 and delay 2
1 and 26.

Next, the controller 12 controls the waveform designation data WA.
The VE, the key-on signal KON, and the touch data TCH are supplied to the excitation signal generator 13, and the input gain multiplication coefficients IG ₁ and IG ₂ are multiplied by the multipliers 14 and 15, respectively.
Supply to. As a result, the excitation signal generation unit 13 generates an excitation signal having a signal waveform designated by the waveform designation data WAVE at the generation timing designated by the key-on signal KON and the touch strength designated by the touch data TCH. Output. This excitation signal is applied to the multiplier 14
And 15 respectively, the input gain multiplication coefficient IG ₁
And IG ₂ and then loop circuits 16 and 1
7 are supplied respectively.

Next, the signal input to the loop circuit 16 is input from the first input terminal of the adder 18, and then given a predetermined characteristic based on the coefficient FL ₁ in the timbre control filter 19, and the APF 20 In FIG. 3, a phase delay characteristic is added according to its own frequency for fine pitch matching based on the coefficient Df _1, and thereafter, a delay is delayed for a predetermined time based on the coefficient DN ₁ in the delay 21, and a positive value is applied in the multiplier 22. are coefficients LG ₁ of the multiplication is fed back to the second input terminal of the adder 18. Therefore, the loop circuit 1
The signal input to 6 changes its phase difference between the frequency components as the circulation in the loop circuit 16 is repeated, and gradually attenuates to give a predetermined comb-shaped characteristic.
The signal circulating in the loop circuit 16 is extracted from the APF 20 as a musical tone signal having an integral overtone structure of the fundamental vibration 2f ′ as shown in FIG. 8B, that is, an even overtone structure of the fundamental vibration f ′ of the loop circuit 17. Be done.

On the other hand, the signal input to the loop circuit 17 is input from the first input terminal of the adder 23, and then given a predetermined characteristic based on the coefficient FL ₂ in the tone color control filter 24, and then in the APF 25. After the phase delay characteristic is given according to the frequency of the self based on the coefficient Df ₂ , the delay 26 is delayed for a predetermined time based on the coefficient DN ₂ , and further, the negative coefficient (−
LG ₂ ), and is fed back to the second input terminal of the adder 23. Therefore, the signal input to the loop circuit 17 is gradually attenuated as the phase difference between the frequency components is changed as the circulation in the loop circuit 17 is repeated, and a predetermined comb characteristic is given. Loop circuit 17
The signal circulating in the APF 25 is taken out from the APF 25 as a tone signal having an odd overtone structure of the fundamental vibration f'as shown in FIG.

Next, the output signal of the loop circuit 16 is multiplied by the coefficient OG ₁ shown in FIG. 4B in the multiplier 29, and then input to the first input terminal of the adder 31. On the other hand, the output signal of the loop circuit 17 is multiplied by the coefficient OG ₂ shown in FIG. 4C in the multiplier 30, and then input to the second input terminal of the adder 31. As a result, the adder 31 adds the output signal of the multiplier 29 and the output signal of the multiplier 30 and outputs it as the musical tone signal MS.

FIG. 5 shows an example of the spectrum structure of the tone signal MS according to time. FIG. 5A shows FIG.
It is a spectrum structure of a part of (b), that is, an attack release part, and this part includes both odd harmonics and even harmonics. 5 (b) is shown in FIG. 4 (b).
This is the spectrum structure of the part b of the above, and this part has only odd overtones and has a clarinet-like mellow tone color. Further, FIG. 5C is a portion c of FIG. 4B,
That is, it is the spectrum structure of the part that makes aftertouch play, and this part includes odd overtones and some even overtones. The envelope of the spectrum structure shown in each of FIGS.
And tone color control filters 19 and 24 constituting
It is determined by the characteristics of.

As described above, according to the above-described embodiment, it is possible to synthesize a musical tone signal which includes abundant harmonics and whose harmonic composition changes greatly with time. . Further, by alternately switching the magnitude relationship between the output gain multiplication coefficient OG ₁ and the output gain multiplication coefficient OG ₂ according to time, a pulse width modulation (Pulse Width Modulation) which is popular in analog synthesizers is switched.
ation) system, it is possible to obtain a tone similar to the tone modulated. That is, the duty of the pulse is 50%
If set to, the tone will be an odd overtone structure and the duty will be 10
When it is set to 0%, the musical tone has an integer overtone structure, so that it is possible to synthesize a musical tone that changes with time, similarly to the musical tone modulated by the pulse width modulation method.

In the above-described embodiment, the example in which the one-stage loop circuits 16 and 17 are connected in parallel is shown, but the present invention is not limited to this. For example, the number of loop circuits connected in parallel may be increased. Further, the loop circuit 16 having a plurality of stages connected in series and the loop circuit 17 having a plurality of stages connected in series may be connected in parallel. In this case, it is possible to synthesize a musical sound having a sharp pitch and a certain pitch feeling.

Further, in the above-described embodiment, an example in which the same excitation signal is supplied from the excitation signal generation unit 13 to the multipliers 14 and 15 has been shown, but different excitation signal generations are applied to the multipliers 14 and 15, respectively. Different excitation signals output from the units may be supplied. Further, the waveforms of these excitation signals may be impulse waveforms, noise waveforms, or predetermined waveforms. Further, these excitation signals may be continuously supplied to each loop circuit, or only the initial waveform may be supplied. The tone color of the synthesized musical tone can be delicately changed depending on the waveform of the excitation signal and its supply method.

Further, in the above-described embodiment, the loop circuits 16 and 17 are composed of the adder, the tone color control filter, the APF, the delay and the multiplier, but the present invention is not limited to this. The loop circuit 16 may include a filter whose characteristics are controlled by tone color, a delay whose delay time is controlled by pitch, and a multiplier which multiplies a positive multiplication coefficient, and the loop circuit 17 is
It suffices to include the filter and delay described above and a multiplier that multiplies a negative multiplication coefficient.

In addition, in the above-described embodiment, an example in which the output gain multiplication coefficients OG ₁ and OG ₂ are controlled according to the after-touch data AT is shown, but the present invention is not limited to this, and the input gain multiplication coefficient IG is used. Similar control may be performed for ₁ and IG ₂ . In this case, the excitation signal is preferably continuously supplied to the multipliers 14 and 15, and the loop circuit is also preferably connected in series. Further, in the above-described embodiment, the example in which the total delay time of each of the loop circuits 16 and 17 is set to the same value has been shown, but the present invention is not limited to this, and the special ratio is set so as to have an integer ratio relationship. You may make it synthesize | combine a musical sound.

[0033]

As described above, according to the present invention, it is possible to synthesize a musical tone signal which includes abundant overtones and whose overtone structure greatly changes with time. Therefore, since the tone color of one musical tone changes extremely with time, it is possible to give the musical tone a wide range of expressions.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an electronic musical instrument to which a musical tone synthesizer according to an embodiment of the present invention is applied.

FIG. 2 is a diagram for explaining one method of generating an output gain multiplication coefficient OG ₁ .

FIG. 3 is a diagram for explaining one method of generating an output gain multiplication coefficient OG ₂ .

FIG. 4 Key-on signal KON, output gain multiplication coefficient OG
FIG. 3 is a diagram showing an example of waveforms of ₁ and OG ₂ , and after-touch data AT.

FIG. 5 is a diagram showing an example of a spectrum structure of a musical tone signal MS according to time.

FIG. 6 is a block diagram showing a configuration example of a musical sound synthesizer used in a conventional electronic musical instrument.

FIG. 7 is a diagram showing sound pressure distributions of a fundamental wave f ′ of a musical sound produced by a resonance phenomenon based on a basic structure of a wind instrument such as a clarinet, and odd harmonics 3f ′ and 5f ′.

FIG. 8 is a diagram showing an example of a spectrum structure of a musical tone including odd harmonics, a musical tone including even harmonics, and a musical tone obtained by mixing them.

FIG. 9 is a block diagram showing a configuration example of a musical sound synthesizer used in a conventional electronic musical instrument.

FIG. 10 is a diagram showing a sound pressure distribution of a fundamental wave f of a musical tone and integer overtones 2f and 3f produced by a resonance phenomenon based on a basic structure of a wind instrument such as a flute.

[Explanation of symbols]

13 ... Excitation signal generation section (excitation signal generation means), 16,
17 ... Loop circuit (first loop means, second loop means), 29, 30 ... Multiplier (mixing means), 31 ...
Adder (mixing means).

Claims (1)

[Claims] 1. An excitation signal generating means for generating an excitation signal having a predetermined waveform, and giving the excitation signal a characteristic according to a tone color,
First loop means having a positive loop gain, which is delayed for a predetermined first time and is repeatedly circulated, and a characteristic according to a tone color is given to the excitation signal,
Second loop means having a negative loop gain, which is delayed by a second time having the same or substantially integer ratio relationship with the first delay time, and is repeatedly circulated; and an output signal of the first loop means. And a mixing means for mixing the output signal of the second loop means with each other.