JPH0365996A - Musical sound synthesizer - Google Patents

Abstract

PURPOSE:To easily enable resonance at high-order resonance frequency by attenuating the signal of a signal processing means, connected to a signal scatter junction where an exciting signal inputted from an exciting means is inputted first, by a specific quantity. CONSTITUTION:One of signal processing means connected to the signal scatter junction 20 to which the exciting signal inputted from the exciting means 10 is inputted first is provided with a means 11 which attenuates the signal by the specific quantity. Thus, the means 11 which attenuates the input signal by the specific quantity is interposed as a signal processing means in the 1st signal scatter junction 20 and then the transmission gain of multi-peak transmission quantity frequency characteristics corresponding to primary resonance frequency is decreased. Consequently, the system consisting of the exciting means, respective signal processing means, and respective signal scatter junctions can be controlled so as to resonate at the high-order resonance frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a musical tone synthesis device particularly suitable for use in synthesizing wind instrument sounds.

"Prior Art" A method is known in which a model obtained by simulating the sound production mechanism of a natural musical instrument is operated, thereby synthesizing the musical tones of a natural musical instrument. The most basic model of a wind instrument such as a clarinet is a model with a closed-loop structure that connects a nonlinear amplification element that simulates the acoustic characteristics of a reed and a bidirectional transmission circuit that simulates a resonant tube. . In this model, when a signal is output from the nonlinear amplification element, this signal is input to the bidirectional transmission circuit as a traveling wave signal, reflected at the end of the bidirectional transmission circuit, and this reflected wave signal is transmitted to the bidirectional transmission circuit. is fed back to the nonlinear amplification element via. In this way, the propagation of air pressure waves in a wind instrument is faithfully simulated by a closed loop circuit consisting of a nonlinear amplification element and a bidirectional transmission circuit.

In addition, actual wind instruments are provided with holes for controlling pitch, so-called tone holes, and models that simulate wind instruments including these tone holes are known. In this model, a signal processing circuit called a signal scattering circuit (hereinafter abbreviated as a circuit) is inserted between each bidirectional transmission circuit in correspondence with the tone hole. Each junction performs arithmetic processing such as coefficient multiplication on each input signal from an adjacent bidirectional transmission circuit, and the arithmetic results are supplied to the adjacent bidirectional transmission circuit.

The multiplication coefficients and the like in this arithmetic processing are switched depending on the open/closed state of the tone hole.

In this case, the signal fed back to the nonlinear amplification element is the sum of the components folded back at each junk signal. Moreover, as mentioned above, since the multiplication coefficient for calculation in each junk signal is switched corresponding to the open/closed state of the tone hole, the transmission amount frequency characteristic when looking from the nonlinear amplification element to the bidirectional transmission circuit side. is switched according to the open/closed state of the tone hole.

This transmission amount frequency characteristic is determined by the frequency (first order) corresponding to the delay time until the output signal of the nonlinear amplification element is returned to the nonlinear amplification element after being folded back at the junk signal corresponding to the open tone hole, and its It becomes a multimodal characteristic having a resonant frequency at each frequency (higher order) that is an integer multiple. Note that this type of technology is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-40.
It is disclosed in Publication No. 199.

``Problem to be Solved by the Invention'' By the way, when actually playing a wind instrument, for example, by adjusting the strength of the blowing pressure, the resonant tube is caused to resonate at the first resonance frequency determined by the open position of the tone hole, It is relatively easy to resonate or switch at a high-order resonant frequency.

However, although the above-mentioned conventional musical tone synthesizer can obtain multimodal resonance characteristics, there is a problem in that it is difficult to control it so as to obtain resonance at a higher-order resonance frequency.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a musical tone synthesizer that can be easily controlled to resonate at a high-order resonance frequency.

"Means for Solving the Problems" In order to solve the above problems, the present invention provides a plurality of signal processing means for performing predetermined signal processing on each forward and reverse input signal and outputting each input signal, and each of the above-mentioned signals. Means for connecting signal processing means, comprising: (a) product-sum calculation means for multiplying each output signal of the signal processing means by a predetermined coefficient and adding the respective multiplication results; and (b) the product-sum calculation means. A plurality of signal scattering junks having distribution means for calculating and outputting an input signal to the signal processing means based on the result and an output signal of the signal processing means, the plurality of signal processing means and a plurality of signal scattering junks. an excitation means for inputting an excitation signal to a circuit formed by connecting a signal scattering junction, and a signal scattering junction to which an excitation signal input from the excitation means is first inputted among the signal scattering junctions. The present invention is characterized in that a means for attenuating the signal by a predetermined amount is inserted into one of the signal processing means connected to the.

"Operation" According to the above configuration, a part of the excitation signal output from the excitation means is returned to the excitation means at the signal scattering junction where it first reaches. The signal that has passed through the first signal scattering junction further passes through each subsequent signal scattering junction, and at each signal scattering junction that it passes, a portion is folded back and returned to the excitation means. Therefore, the signal fed back to the excitation means is composed of each component folded back at each signal scattering junction, and the transmission amount frequency characteristic when the circuit consisting of each signal processing means and each signal scattering junction is viewed from the excitation means. has a multimodal characteristic with multiple resonance frequencies.

Then, as mentioned above, if a means for attenuating the input signal by a predetermined amount is inserted as a signal processing means into the first signal scattering junk filter, in the above multimodal transmission frequency characteristic, the transmission gain at the following resonance frequency can be lowered. Therefore, by doing so, the system including the excitation means, each signal processing means, and each signal scattering junction can be controlled to resonate at a high-order resonance frequency.

"Example" Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a musical tone synthesizer according to an embodiment of the present invention. Furthermore, FIG. 2 is a diagram showing the configuration of a physical model of a clarinet simulated by this musical tone synthesis device.

First, the physical model shown in FIG. 2 will be explained.

In FIG. 2, 1 is a resonance tube (tube section) of a wind instrument, 2 is a mouthpiece section, 2a is a reed, TH is one tone hole formed in the resonance tube 1, and RTC is a register tube.

The clarinet's sound production mechanism will be explained below with reference to this physical model. When a blow player holds the mouthpiece portion 2 in his mouth and blows into it, the reed 2a is displaced due to the blowing pressure P and its own elastic properties (arrow 2S). As a result, air pressure waves (compression waves) are generated inside the tube of the reed 2a, which become traveling pressure waves F and are sent toward the terminal end IE of the resonance tube 1. Then, the traveling pressure wave F is reflected at various places in the resonance tube I and at the terminal end IE, and returns to the lead 2a as a reflected pressure wave R, and the lead 2a receives the pressure PR from the reflected pressure wave R. Therefore, while playing,
If the pressure of the reflected pressure wave R is PR, then the total pressure PA that the lead 2a receives is as follows: vibrates due to A musical tone is generated when the vibration of the reed 2 and the reciprocating motion of the pressure waves F and R within the resonance tube 1 come into resonance.

The primary resonance frequency at this time is switched by opening and closing the tone hole TH formed in the resonance tube l. That is, when the tone hole TH is opened and closed, the flow of pressure waves near the tone hole TH changes accordingly, and the effective length of the resonance tube l changes, thereby switching the resonance frequency. Ru.

Hereinafter, the state of the air pressure wave at a point j near the tone hole T H of the resonance tube l will be explained.

When the tone hole TH is open> When the tone hole TH is open, the air pressure Pj at point j is: Pj=a+oN p, + + aloft P
t+ asort Ps+ (2). Here, P, + is the pressure of the air pressure wave flowing into point j from the lead 2a side of resonance tube l, P, + is the pressure of the air pressure wave flowing into point j from the end IE side of resonance tube l, In addition, Ps+ indicates the pressure of the air pressure wave flowing from the tone hole T) (also, a, on, assort and a
moff is a coefficient corresponding to the contribution of each air pressure wave flowing into point j to the air pressure Pj at point j, and is expressed by the following formula (3)
It is given by ~(5).

alorr= 2φ−/(φ,! 10φ1+φ1) ・・
...(3) 6*oH= 2φ1/(φ,'+φ1+
φ3′) ・・・・・・(4) a, oH= 2φ, l
/(φ1'+φ1+φ,') ......(5) Here, φ is the diameter of the portion of the resonant tube l on the lead 2a side, φ,
is the diameter of the terminal end IE side of the resonance tube 1, and φ is the diameter of the tone hole TH.

On the other hand, in FIG. 2, from point j to lead 2a of resonance tube l
The pressure Pl of the air pressure wave flowing out in the direction IE, the pressure Pl of the air pressure wave flowing out in the direction of the end IE of the resonance tube 1, and the pressure Pl of the air pressure wave flowing out to the tone hole T I (
Then, these are p, −= Pj−P, ten
・・・・・・(6) Pa−= Pj Pa ten
・・・・・・(7) P s-= P 3 P @
10...(8).

An air pressure wave (pressure P
. . Furthermore, when the tone hole TH is in an open state, the air pressure wave (pressure p s-) flowing out from point j toward the outside of the tone hole TH is reflected at the opening, but
In this case as well, the traveling wave is reflected in the opposite phase.

<When the tone hole TH is in a closed state> In this case, it is considered to be equivalent to a state in which the diameter φ of the tone hole TH becomes O. Therefore, the above formula (3) ~
By substituting φ,=0 into (5), the air pressure Pj of each air pressure wave when the tone hole TH is in the closed state
The coefficient a corresponding to the contribution to
On r a a On is represented by the following formulas (9) to (11)
be guided as follows.

3, on-2φ1'/(φ♂+φ1) ・・・・・・(
9) amon= 2φ−/(φ, 1+φ, t) −・
...-(10) a-on= O--(11) And the air pressure Pj at point j is P j"&IQn P 1+ + atoIt
P t+ a30n P s”・・・・・・(l
2) It becomes.

Signals reflected at various points in the resonance tube 1 as described above are fed back to the lead 2a, and the primary resonance frequency is determined by the most effective component of the signals. When the tone hole TH is open, the primary resonance frequency is determined by the time required for the air pressure wave to travel back and forth between the lead 2a and the tone hole TI. In addition, the transmission amount frequency characteristic of the resonance tube 1 in this case is a multimodal characteristic in which the transmission gain is maximum at the first-order resonance frequency and higher-order resonance frequencies such as 3 times, 5 times, etc. becomes.

Next, the resistor tube RTC will be explained.

As mentioned above, the resonance tube l of a wind instrument has a multimodal transmission frequency characteristic, but the resistor tube RTC is provided to promote resonance at a high-order resonance frequency in the resonance tube 1. be. Among existing wind instruments, there are wind instruments that are equipped with holes (called octave keys) corresponding to register tubes RTC in order to facilitate pitch switching over one octave or more. As shown in Figure 2,
At points near the resistor tube RTC, scattering of air pressure waves occurs. Q l ”+ Q R”+ Q 3+
is the pressure of the air pressure wave flowing into the neighboring point k, Q,−,Ql
, Q, - is the pressure of the air pressure wave flowing out from the neighboring point k. When the resistor tube RTC is in a closed state, the components of the air pressure wave returned to the lead 2a are predominantly those reflected and returned at the tone hole TH or the terminal end IE. On the other hand, when the resistor tube RTC is in an open state, the scattering of the air pressure wave at the resistor tube RTC becomes significant, so that the component reflected at the resistor tube RTC is emphasized in the air pressure wave fed back to the lead 2a. Incidentally, since the scattering of the air pressure wave at this point k is the same as that at the point j near the tone hole TH described above, a repeated quantitative explanation will be omitted here.

Next, the musical tone synthesis apparatus shown in FIG. 1 constructed based on the physical model shown in FIG. 2 will be explained. In the figure, an excitation circuit 10 corresponds to the mouthpiece section 2 in FIG. 2, and a resonance circuit 30 corresponds to the resonance tube 1. Furthermore, the Junxillon 20 inserted between the excitation circuit 10 and the resonance circuit 30 simulates the scattering of air pressure waves at the connection between the mouthpiece section 2 and the resonance tube 1.

In this junk cylinder 20, the output signal from the resonant circuit 30 and the output signal from the excitation circuit 10 are added by addition 'A318 and input to the resonant circuit 30, and the output signal from the adder 18 and the output signal from the resonant circuit 30 are added together. 119 and input to the excitation circuit 10.

The excitation circuit IO includes subtractor IL filters 12 and 13,
Adder 14, ROM15, multipliers 16 and 17 and IN
It consists of V. When a musical tone is generated, information corresponding to the blowing pressure P1 embouchure E (the pressure when the mouthpiece is held in the mouth) is provided from the musical tone control circuit 100.

The subtracter 2 receives a signal input from the resonance circuit 30 via the junk cylinder 20, that is, a signal corresponding to the air pressure PR of the reflected wave R from the resonance tube l in FIG. 2, and a signal corresponding to the blowing pressure P. A signal is input. And the above formula (
The calculation 1) is performed, and a signal corresponding to the air pressure PA applied to the lead 2a is obtained.

The output signal of the subtracter 11 is band-limited by a filter 12. This filter 12 is constituted by a first-order low-pass filter, and is inserted to prevent the amplitude of the signal circulating between the excitation circuit 10 and the resonant circuit 30 from becoming significantly large at a specific frequency. The output signal P of the filter 12 is input to the filter 13, and is inverted by the multiplier INV and input to the multiplier 16. The signal P passes through the filter 12 to remove high frequency components. This simulates the response characteristics of the road 2a that absorbs sudden pressure changes.

Then, the adder 14 adds a signal corresponding to the embouchure E to the output signal P of the filter 13 to obtain a signal P corresponding to the pressure actually applied to the reed. This signal P is then given to the ROM 15 as an address. As a result, a table of nonlinear functions stored in advance in the ROM 15 is referred to, and the cross-sectional area of the gap between the reed 2a and the mouthpiece portion 2, that is,
A signal Y corresponding to the admittance to the airflow is output. Then, the signal Y and the signal -P are multiplied by the multiplier 16, and a signal FL corresponding to the flow velocity of air passing through the gap between the reed 2a and the mouthpiece portion 2 is obtained.

Then, the signal FL is multiplied by a multiplication coefficient G by a multiplier 17. Here, the multiplication coefficient G is a constant determined according to the pipe diameter near the mounting part of the mouthpiece part 2 in the resonance pipe l. , which corresponds to the difficulty of passing the airflow, that is, the impedance to the airflow.Therefore, from the multiplication W17, a signal corresponding to the change in air pressure occurring at the mouthpiece side entrance of the resonance tube 1 is obtained. is obtained.Then, this signal is at the junction 20
The signal is input to the resonant circuit 30 via.

In the resonant circuit 30, delay circuits D jr, D kr
, Dsr, Dllr, Dkr, and Djr each correspond to the propagation path of the air pressure wave in the resonance tube 1 in FIG.

More specifically, the lead 2a and the resistor tube RT
The propagation delay of the air pressure wave between the resistor tube RTC and the tone hole TH is simulated by the delay circuits Djf and Djr, the propagation delay between the resistor tube RTC and the tone hole TH is simulated by the delay circuits Dkj and Dkr, and the propagation delay between the tone hole TH and the tone hole TH is simulated. The propagation delay between the termination part IE and the delay circuit D
Shimmied by mf and Dmr.

When the output signal of the resonant circuit 30 is input to the termination circuit TRM, it is 11) range limited by the low-pass filter ML,
Furthermore, it is multiplied by a negative coefficient γ by multiplier IV and returned to the resonant circuit 30. In this way, the frequency characteristics of the acoustic loss at the termination IE and the phase inversion accompanying reflection are simulated.

The junction JTH in the resonant circuit 30 simulates the scattering of air pressure waves at a point j near the tone hole TH in FIG.
Multiplier M, , M□M s , M 4, subtraction 481.
A *, A @, delay circuit D T H,, D T H
1 and a low-pass filter LPFTH. Adder Aj contains a signal obtained by multiplying the output signal of delay circuit Dkf (corresponding to pressure P in FIG. 2, 10) by a coefficient a+ by multiplication WM, and an output signal of delay circuit Dmr (corresponding to pressure P in FIG. 2).

(corresponding to
, corresponding to 10) multiplied by a coefficient 83 by a multiplier M. In addition, as each coefficient a,, a□a, when the tone hole TH is in an open state, the coefficient at according to the above equations (3) to (5) is input from the musical tone control circuit lOO.
ofL a*orr* asorr is given and when the tone hole TH is in the open state, the above equations (9) to (1
The coefficient a+on+ a*on+ 83on according to 1) is given.

Then, the addition result of adder Aj, that is, the signal corresponding to the air pressure Pj at point j, is obtained by subtraction &'i, , At and A
, is input. Then, in the subtracter A, the output signal (pressure p, equivalent to 10) of the delay circuit Dkf is subtracted from the output signal of the adder Aj, and the subtraction result (pressure P.

- equivalent) is sent to the delay circuit Dkr. Also, subtraction 2R
At A, the output signal of the delay circuit Dmr (pressure P, equivalent to 10) is subtracted from the output signal of the adder Aj, and the subtraction result (corresponding to pressure Pr) is sent to the delay circuit Da+r. Furthermore, in the subtraction DA, the delay circuit D T is input from the output signal of the adder A3.
The output signal of H* (pressure P, equivalent to 10) is subtracted, and the subtraction result (corresponding to pressure P1) is sent to the delay circuit DTH.

Then, the signal input to the delay circuit DTH is delayed by a predetermined time and is passed through the low-pass filter L P F T ! 1 and gives the acoustic loss at the tonehole opening. Then, the output signal of the low-pass filter LPFTH is multiplied by the reflection coefficient the for the air pressure wave at the opening of the tone hole TH by a multiplier M4. This reflection coefficient the is supplied from the musical tone control circuit 100, and is -1 when the tone hole TH is open;
It is switched to 1 when it is in the closed state. And multiplier M
The multiplication result of 4 is delayed by a delay circuit DTH, and is input to a subtracter A and a multiplier M. delay circuit DT
The delay times of H and DTH are equal to the height of the tone hole TH, that is, the time required for the air pressure wave to travel back and forth across the cylindrical portion of the tone hole TH. In this way, the propagation of the air pressure wave at the point j near the tone hole T H described above is simulated.

The Junk Silane J RTC is provided to calculate the scattering of air pressure waves in the resistor tube RTC.

Here, each multiplication coefficient bt, bt, bs is each diameter φtb, φ, b corresponding to the resistor tube RTC.

It is determined based on φ and b. Further, LPFRTC is a low-pass filter that provides acoustic loss when the resistor tube RTC is open, and DRTC is a delay circuit having a delay time depending on the height of the resistor tube RTC. Also, the reflection coefficient rtc is the resistor tube R
It can be switched according to the opening and closing of the TC. Note that the configuration of the Junction Silan J RTC is exactly the same as that of the Junction JTH, and the only difference is in each coefficient used in the calculation as explained above. Therefore, Junxyron J
A detailed description of the configuration regarding the RTC will be omitted.

Now, the delay circuit DJLD j in this musical tone synthesizer
r, D kf, D kr, D mf, D sr
Each has a plurality of delay elements, and is configured to be able to switch and control the number of stages of delay elements that contribute to signal delay.

The delay circuits Djf and Dir receive delay stage number data Q1, and the delay circuits Dkr and Dkr receive delay stage number data 12! However, the delay circuits Dmr and Dmr are given delay stage number data m from the tone control circuit 100, and the allocation of these delay times is switched in accordance with the position of the tone hole TH to be opened. In addition, as a specific circuit of this type of delay circuit that can control the delay time, for example, an input signal is input to a shift register driven by a shift clock of a predetermined cycle, and a desired one of the outputs of each stage of the shift register is input. It is possible to use a method in which a selector or the like selects and outputs one corresponding to the delay time.

Here, the control of the distribution of delay time corresponding to the above-mentioned opening/closing operation of the tunnel hole will be described in detail. Now, it is assumed that the tone hole TH in FIG. 2 is in an open state among the many tone holes provided in the resonance tube 1, and is the tone hole closest to the lead 2a. In this case, the sum of the delay stage number data el and h is equal to the delay stage number n corresponding to the distance from the lead 2a to the tone hole TH, and the ratio of the delay stage number 121 to the delay stage number n is constant. is set to the value. The relationship between the number of delay stages 121 and the number n of delay stages will be described later.

In addition, the number of delay stages corresponding to the total length of the resonance tube l is (in the case of Ig, stage number data m where m=Qs-n is supplied to the delay circuits Dar and Dmr. In this way, the delay time of each delay circuit is is set. And Junk Thin JT
The coefficients aloff, amoH, and atorr are supplied to H, and -1 is supplied as the reflection coefficient the. On the other hand, when all the tone holes are covered with fingers, the stage number data n and the morbidity are determined corresponding to the tone hole position closest to the terminal IE.

The junction JTH has coefficients aton, a
m On + a @ Ofi is supplied, and l is supplied together with the reflection coefficient the. In addition, it corresponds to the opening/closing operation of the resistor tube RTC.
The reflection coefficient rtc in TC and the multiplication coefficients b+, b□b for product-sum calculation are switched.

A musical tone synthesizer having the configuration shown in FIG. 1 as described above was fabricated as a prototype, and the musical sound waveform was evaluated. Below, we will list and explain each parameter that was set for the prototype in this evaluation.

<List of design parameters> [Filters] ◇Low pass filter for tone hole TH LPFT H cutoff frequency fcTII = 2500 [1-1z
]◇Low pass filter LPF for resistor tube RTC
RTC cutoff frequency rcRTc = 7000 [Hz] ◇ Final Qi [Power of low-pass filter ML for IE/nodoff frequency fcML - 2000 [Hz] ◇ Force of filter 13 (low-pass filter)/nodoff frequency fcdcf =
1500 [Hz] [Number of stages of delay circuit (number of shift register stages)] ◇Delay circuits D jf, D kf and Dmf
(Delay circuit Djr.

Dkr and D sr) (corresponds to the entire length of resonance tube 1 > Qs-82) ◇Total number of delay stages of delay circuits DJr and D kf (delay circuits Djr and okr) (corresponds to the distance from lead 2a to tone hole TH) Corresponding) n = 40 ◇ Super delay path Djr (
Number of delay stages of delay circuit Djr) (corresponds to the distance from lead 2a to resistor tube R'rC) L depth 10 ◇Number of delay stages of each of delay circuits DTH and DTH2 (corresponds to the height of tone hole TH) )i2Tll=
1◇Number of delay stages for each of the delay circuits DRTC and DRTC (corresponding to the height of the resistor tube R'rC) +2
RTC depth [Tone hole TH related parameters] φ== 24
[mml φ, = 2 4 C-1] φ = 16 C++nl Based on the values of these valley diameters, the above multiplication coefficient a, orr, 5
Calculate tart and asoff, and set Junkshi*7J
It was set to TH.

Also, the multiplication coefficient (reflection coefficient) the of the multiplier M is -1
(corresponding to the state where the tone hole TH is open).

[Resistor tube RTC related parameters] φ1b
=19 [IIIm] φ, b= 19 [+aI! +] φ, l) = s [Question] Based on the values of these valley diameters, calculate the above multiplication coefficient boff,
b*o[+ b3orr, b, on, boon,
baon was calculated and set to Junk Silan J RTC.

[Other parameters] ◇Multiplication coefficient of inversion circuit tV (reflection coefficient of termination part IE) γ
= -0,9 0 Multiplying coefficient of multiplier 17 (impedance to air flow of resonance tube 1) G = 0.3 Then, with each of the above parameters set, the reflection coefficient rtc at junction J RTC is changed to various values. The musical tone synthesizer shown in Fig. 1 was evaluated. In this evaluation, we will use the excitation circuit 10 from the musical tone synthesizer shown in Figure 1.
, input an impulse from point tl, observe the response at point tl, apply FFT (fast Fourier transform) to the impulse response, and obtain the results shown in Figure 3(a).
The transmission amount frequency characteristics shown in (b) were obtained. Figure 3(a)
As shown in , when the reflection coefficient is 1 (resistor tube R
In the TC closed state), the transmission gain is maximum at the first-order resonance frequency rl. Therefore, the musical tone synthesizer resonates according to the first-order resonance frequency rl. Corresponding to the opening of the resistor chain RTC, when the reflection coefficient rtc is set to -1, the primary resonance frequency shifts slightly to the high frequency side (frequency 1 krt
a). However, since the maximum gain is reached at this resonant frequency rtc, resonance at a higher-order resonant frequency does not occur even though the resistor tube RTC is opened. As shown in FIG. 3(b), the reflection coefficient rtc is -
When it is set to 0, 9 or -0, 8, in each of these cases, the gain at the first-order resonance frequencies ftb and ftc is reduced, and the gain at the third-order resonance frequency rl becomes maximum. As a result of this evaluation, when the resistor tube RTC is in the open state, by giving a coefficient whose absolute value is smaller than 1, that is, a reflection coefficient rtc including an attenuation coefficient, to the junction J RTC, It was found that resonant operation at higher frequencies can be easily obtained.

In this musical tone synthesizer, the reflection coefficient rLc when the resistor tube RTC is open is determined based on the evaluation results obtained in this manner. Therefore, when the resistor tube RTC is in the closed state, the total delay time of the delay circuit inserted between the excitation circuit 10 and the junction JTH is 8.
Resonant operation at the first-order resonant frequency corresponding to the
A musical tone having the pitch is generated. In addition, when the resistor tube RTC is opened and the reflection coefficient rLc in the Junk Silane J RTC is switched to a negative coefficient that includes attenuation, the resonant frequency where the maximum gain is obtained is switched to a higher-order frequency. Resonant operation can be obtained.

In addition, in the above-mentioned embodiment, the case where the delay time of the 3% row wave and the delay time of the reflected wave were made equal was explained, but the signal output from the excitation circuit 10 is
rl 'r If the total time until it is fed back to the excitation circuit IO via C or JTI-1 or the termination circuit TnM is constant, then the distribution of the delay time for the traveling wave and the delay time for the reflected wave is It doesn't matter if it's unbalanced.

"Effects of the Invention" As explained above, according to the present invention, there are provided a plurality of signal processing means for performing predetermined signal processing on each forward and reverse input signal and outputting the resultant signal, and each of the signal processing means. (a) a sum-of-products calculation means for multiplying each output signal of the signal processing means by a predetermined coefficient and adding the results of each multiplication; A plurality of signal scattering junctions each having one stage of distribution that calculates and outputs an input signal to the signal processing means based on an output signal of the signal processing means, and the plurality of signal processing means and the plurality of signal scattering junctions are connected. an excitation means for inputting an excitation signal to the circuit consisting of the excitation means, and a signal connected to the signal scattering junction to which the excitation signal inputted from the excitation means is inputted first among the signal scattering junctions. Since a means for attenuating the signal by a predetermined amount is inserted into one of the processing means, it is possible to realize a musical tone synthesizer that can easily generate musical tones according to a high-order resonance frequency. can get.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a musical tone synthesizer according to an embodiment of the present invention, FIG. 2 is a diagram showing a physical model of a clarinet simulated by the embodiment, and FIG. 3 is a t+, FIG. 7 is a diagram showing transmission amount frequency characteristics when looking at the resonant circuit 30 side from point Lt. Foot circuit, 100... musical tone control circuit.

Claims (1)

[Scope of Claims] A plurality of signal processing means that performs predetermined signal processing on each forward and reverse input signal and outputs each signal, and means for connecting each of the signal processing means, comprising: (a) (b) product-sum calculation means for multiplying each output signal of the signal processing means by a predetermined coefficient and adding the respective multiplication results; A plurality of signal scattering junctions having a distribution means for calculating and outputting an input signal to the signal processing means, and an excitation inputting an excitation signal to a circuit formed by connecting the plurality of signal processing means and the plurality of signal scattering junctions. and transmitting a predetermined amount of the signal to one of the signal processing means connected to the signal scattering junction to which the excitation signal inputted from the excitation means is first inputted among the signal scattering junctions. A musical tone synthesis device characterized in that a damping means is inserted.