JP2841847B2 - Music synthesizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical sound synthesizer suitable for electronically synthesizing musical sounds of a wind instrument or the like.

2. Description of the Related Art There is known a musical sound synthesizer that operates a model obtained by simulating a sounding mechanism of a natural musical instrument and thereby generates a musical sound of the natural musical instrument. The simulation of the tube has been performed by a linear circuit and a nonlinear circuit using a waveguide digital filter that describes the tube (Japanese Patent Laid-Open No. 63-40199).

"Problems to be Solved by the Invention" By the way, in the above-mentioned conventional tone synthesizer,
Only simulations from the player's mouth to the tube were performed, and the effects of waves propagating in the player's mouth and vocal tract, etc., were ignored. Therefore, there is a problem that a discrepancy occurs between the behavior of the realized musical instrument and the reproducibility is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a musical sound synthesizer capable of obtaining expression of wind instrument performance that is very close to realization.

Means for Solving the Problems To solve the problems described above, the present invention provides a first waveguide network that simulates at least one of the shape of the oral cavity and the vocal tract, and at least a mouse of a wind instrument. Simulating one of a piece and a lead, simulating a second waveguide network cascaded to the first waveguide network, and simulating a wind instrument tube, the second waveguide network A third waveguide network cascaded to the first waveguide network, wherein an excitation signal is supplied to the first waveguide network, and an output of the first waveguide network and the third
Is output to the second waveguide network, and the second waveguide network performs processing using the outputs of the first and third waveguide networks, and the result of the processing is performed. Is output to the first and third waveguide networks.

Further, the present invention is characterized by further comprising a variable means for varying the characteristics of the first waveguide network based on performance information.

[Operation] According to the above configuration, signals are exchanged between the respective waveguide networks, so that mutual influence is exerted between the oral cavity / vocal tract, the mouthpiece / lead, and the wind instrument tube. It can faithfully simulate the phenomenon of meeting.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1) Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention. In the figure, reference numeral 1 denotes a keyboard, which is composed of a white key and a black key. Reference numeral 2 denotes an operation panel on which various parameters for controlling the timbre of a musical tone can be set. A CPU (central processing unit) 3 executes a predetermined program and controls each section of the electronic musical instrument. table
The ROM 4 stores an operation program of the CPU 3, coefficients to be given to the tone synthesis circuit 7 described later, and the like. Also RAM
(Random access memory) 5 is used as a temporary storage area at the time of calculation by CPU 3. Reference numeral 6 denotes an operator for performing various operations, and a control signal corresponding to the operation is supplied to the CPU 3. The tone synthesis circuit 7 is composed of a circuit for simulating a natural musical instrument, and synthesizes a tone signal under the control of the CPU 3. Reference numeral 8 denotes a sound system, based on a tone signal output from the tone synthesis circuit 7,
The speaker 9 sounds.

Next, the above-described tone synthesis circuit 7 will be described with reference to the block diagram shown in FIG. In this figure, the tone synthesis circuit 7 is composed of a tube of a wind instrument such as a clarinet, a mouthpiece of a wind instrument, and a closed loop circuit simulating the oral cavity and vocal tract. That is, the second
As shown in the figure, an oral vocal tract formation circuit 10 for simulating the oral cavity and vocal tract, a mouthpiece simulation circuit 11 for simulating the state of a mouthpiece and a lead, and a tube formation for simulating a tube portion of a wind instrument. It comprises a circuit 12.

The mouthpiece simulating circuit 11 includes adders 15 to 19,
It comprises multipliers 20, 21, a delay 22, and a function generator 23, and performs, for example, the following simulation.

Here, the case of single read is taken as an example. Now, as shown in FIG. 3, the pressure in the mouthpiece MP is q, the mouth M
Is defined as p, and these are further expressed as 2
Divide into two.

q = q _i + q _o (1) p = p _i + p _o (2) Further, the characteristic impedance of the tubular body is Z _T , and the characteristic impedance of the mouth is Z _M. placing the, since the volume flow rate f of the connecting portion of the mouth and instruments equal between the tube part and the oral _{cavity, f = (q o -q i} ) / Z T = (p i -p o) / Z M ...... ............ (3) This is transformed to obtain the following equation.

q _o = q _i + Z _T · f (4) p _o = p _i −Z _M · f (5) where f is a nonlinear function of the difference Δq between the internal pressure and the external pressure of the mouthpiece. And f = F (Δq) (6) Δq = q−p (7) The mouthpiece simulation circuit shown in FIG. 2 realizes the above-described equations (1) to (7). In addition,
The circuit configuration of the mouthpiece simulation circuit 11 differs depending on the simulation mode.

Here, the mouthpiece simulation circuit shown in FIG.
The relationship between 11 and the above equations (1) to (7) will be described below.

According to the simulation described above, the signal p _o is supplied to the oral vocal tract formation circuit 10 to output the signal p _i , and the tube formation circuit 12 is supplied with the signal q _o to output the signal q _i Will be done. That is, the input / output relationship is as shown in FIG. Therefore, the addition result of the adder 18 corresponds to the expression (1), and the addition result of the adder 16 corresponds to the expression (2). Then, the adder 17 performs the operation (q-p) of the equation (7), and the operation result is transmitted via the delay 22 to the function generator.
23, where the calculation of Expression (6) is performed.
Next, the output signal of the function generator 23 is
It is multiplied by Z _M and then input to the adder 15. Adder
At 15, the input signal and P _i are added (algebraic addition), whereby the operation shown in equation (5) is performed. The output signal of the function generator 23, the coefficient Z _T by a multiplier 21 is inputted to the adder 19 after having been subjected. In the adder 19, the signal q _i is added to the input signal, so that the operation shown in the equation (4) is performed. The above is the processing content of the mouse simulation circuit 11.

Next, the configuration of the tube forming circuit 12 will be described with reference to FIG. In the figure, _{J0T to} Jt _-1T are junctions, respectively, and have the configuration shown in FIG. In FIG. 6, reference numerals 25, 26 and 27 denote adders, and reference numerals 28 and 29 denote multipliers. The coefficients of the multipliers 28 and 29 are a and b, respectively.
When the open state of the tone hole having no height is simulated, a + b <2 is set. When the closed state of the tone hole having no height is simulated, a + b = 2 is set. In FIG. 4, those indicated by reference numerals SR and suffixes are shift registers, respectively.
It is controlled by CPU3. The mode of simulation changes depending on the difference in the number of shift stages. Furthermore, LPF _T shown in Fig. 4, a low-pass filter that approximates the losses of the tube end, the gamma _T is the reflection coefficient of the tube end.

Next, the configuration of the oral vocal tract formation circuit 10 will be described with reference to FIG.

J _{m-1M to} J _0M shown in FIG. 5 are junctions, respectively, and are constituted by the circuit shown in FIG. 6 like the above-mentioned junction. However, when the nasal cavity is not considered, the multiplication coefficient is set to a + b = 2. In FIG.
Reference numerals SR and suffixes denote shift registers, respectively, which are the same as those shown in FIG. In addition, LPF _M is a low-pass filter that approximates the loss of the vocal tract termination, γ
_M is the reflection coefficient at the end of the vocal tract. The symbol pr shown in FIG.
Is the force that the player forces on the system. In this embodiment, a signal pr corresponding to the pressing force of the keyboard is used.

The coefficients a and b shown in FIG. 6 are stored in advance in the ROM 4 shown in FIG. 1, read out as appropriate under the control of the CPU, and supplied to each junction. here,
A method for determining the coefficient will be described.

First, the determination of the coefficients in the oral vocal tract formation circuit 10 includes:
This is performed by predicting the shape of the oral cavity. For example, as shown in FIG. 7, a human utterance is recorded by a microphone 30 and the recorded waveform is processed by a linear prediction circuit (variable means) 31 to determine a filter coefficient. In this case, a set of coefficients when the vocal tract and the oral cavity are simulated by the filter is obtained, and the set of coefficients is written in the ROM 4. Further, in determining the coefficients, in order to cope with diversification of playing methods, coefficients for various sounds are obtained, and these are collectively written to the ROM 4.

Here, FIG. 8 shows a specific example of the filter coefficient written in the ROM4. As shown in this figure, combinations of coefficients are written separately for the forms A, B, C,... Of the oral vocal tract to be simulated.

Also, the coefficient at each junction of the tube forming circuit 12 corresponds to the tube to be simulated,
Stored in M4.

(2) Operation of Embodiment Next, the operation of this embodiment having the above configuration will be described.

First, a coefficient to be supplied to the oral vocal tract formation circuit 10 is selected using the operator 6. By this operation, one of the coefficient sets A, B, C... In the ROM 4 is selected. Also,
The coefficient for the tube forming circuit 12 is also selected by operating the operation element 6. Next, when the operator performs using the keyboard, a signal indicating the pressing force of the pressed key is output from the keyboard 1.
Supplied to CPU3. As a result, the CPU 3 creates a signal pr and supplies it to the oral vocal tract formation circuit 10 in the tone synthesis circuit 7 (see FIG. 5). Also, the CPU 3 sets the selected coefficient set to RO
It is read from M4 and supplied to each junction in the oral vocal tract formation circuit 10. The oral vocal tract formation circuit 10 performs a simulation according to the supplied coefficient, and starts forming a tone signal by using the signal pr as an excitation signal. The oral cavity, vocal tract, mouthpiece and tube are simulated by the loop circuit constituted by the oral vocal tract formation circuit 10, the mouthpiece simulation circuit 11 and the tube formation circuit 123, and as a result of this simulation, The obtained tone signal is supplied to the sound system 8. Thereby, a musical sound is emitted from the speaker 9.

In the above operation, the wave propagating in the oral cavity and the vocal tract of the player is also simulated by the oral vocal tract formation circuit, so that the influence of the wave motion on the musical sound is reflected.

(3) Modifications In the above embodiment, the following modifications are possible.

Although the set of coefficients to be given to the oral vocal tract formation circuit 10 is selected by the operator 6, the selection may be made by initial key or after touch of the key instead. When playing a wind instrument, the shape of the performer's mouth and vocal tract is the sound produced (the pitches and the like are performance information).
Therefore, a tone that is closer to the actual performance is uttered when changed according to the initial touch or the like than when the simulation mode is fixedly set.

Although the embodiment is an example of an electronic musical instrument using a keyboard, the present invention can also be applied to an electronic musical instrument using a mouthpiece. In this case, a configuration can be adopted in which a coefficient to the oral vocal tract formation circuit 10 is selected according to the strength (embouchure) of biting the mouthpiece.

The shift register SR used in the embodiment may be constituted by a RAM, and may use other delay means.

The present invention is not limited to the pronunciation algorithm in the embodiment, but may use another algorithm, that is, a pronunciation algorithm based on the bowing or striking. In this case, the case of bowing can be considered in the form of, for example, vibration of bow hair.

The embodiment described above is realized by hardware, but may be realized by a microprogram or software.

Each coefficient supplied to the oral vocal tract formation circuit 10 and the tube formation circuit 12 may be key-scaled. That is, each coefficient may be allocated in advance in accordance with the tone range, and a set of coefficients corresponding to the played treble may be selected at any time.

When the tubular body forming circuit 12 simulates a tall tone hole and when the oral vocal tract forming circuit 10 also considers branching such as a nasal cavity, the junctions shown in FIG. 6 each become a three-point junction.

In order to change the mouth shape as smoothly as possible,
A table corresponding to FIG. 8 is created so that the oral cavity and the vocal tract shape change little by little in the order of A, B, C... Even if the value of the operator corresponding to the change in the vocal tract greatly changes. Rather than suddenly becoming the desired vocal tract shape, the value of the shape J _1M that gradually shows the shape using interpolation table values etc.
a, b, J The a, b ... of _2M may be changed.

[Effects of the Invention] As described above, according to the present invention, at least one of the first waveguide network simulating the shape of the oral cavity and the vocal tract, and at least one of the mouthpiece and the lead of the wind instrument A second waveguide network cascaded to the first waveguide network, and a tube of a wind instrument simulated and cascaded to the second waveguide network. An excitation signal is supplied to the first waveguide network, and an output of the first waveguide network and an output of the third waveguide network are output from the second waveguide network. Of the second wave guide The network performs processing using the outputs of the first and third waveguide networks, and outputs the result of the processing to the first and third waveguide networks. Since signals are exchanged between the mouth and vocal tract, the mouthpiece / lead, and the wind instrument tube, the phenomenon of mutually affecting each other can be faithfully simulated.

Further, since the characteristics of the first waveguide network are variable based on the performance information, various musical effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a mouthpiece simulation circuit 11 of the embodiment, and FIG. FIG. 4 is a block diagram showing a configuration of a tube forming circuit 12 of the embodiment, and FIG. 5 is a block diagram showing a configuration of an oral vocal tract forming circuit 10 of the embodiment. FIG. 6 is a block diagram showing the structure of the junction between the oral vocal tract forming circuit 10 and the tubular body forming circuit 12, and FIG.
FIG. 8 is a conceptual diagram showing a state of a set of coefficients stored in the ROM 4. 10: oral vocal tract formation circuit (first waveguide network), 11: mouthpiece simulation circuit (second wave guide network)
12) Tube formation circuit (third waveguide network).

Claims (2)

(57) [Claims] A first waveguide network for simulating at least one of a mouth and a vocal tract, and a first wave guide for simulating at least one of a mouthpiece and a lead of a wind instrument; A second waveguide network cascaded to the guide network; and a third waveguide network simulating a wind instrument tube and cascaded to the second waveguide network. An excitation signal is supplied to the first waveguide network; an output of the first waveguide network and an output of the third waveguide network are input to the second waveguide network; The waveguide network comprises the first and third Subjected to processing using the output of the E over blanking guide network, the tone synthesis apparatus and outputs the result of the processing in the first and third waveguide network. 2. The musical sound synthesizer according to claim 1, further comprising a variable means for varying characteristics of said first waveguide network based on performance information.