JPH0721715B2 - Musical tone signal generator - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone waveform signal forming apparatus used in electronic musical instruments, music education devices, toys and the like, and more particularly to a musical tone waveform signal forming apparatus for forming a desired musical tone waveform signal while cyclically delaying waveform signals.

[Prior art]

Conventionally, a device of this type is provided with a non-linear conversion circuit section in a circulating signal path including a signal delay means, as disclosed in, for example, Japanese Patent Laid-Open No. 63-40199, and the circuit is circulated in the non-linear conversion circuit section. The start control signal from the outside is superposed on the waveform signal of, the formation of the waveform signal is started according to the control signal from the outside, and the desired musical tone waveform signal is formed by repeatedly circulating the waveform signal. Was there.

[Problems to be Solved by the Invention]

However, in the above-mentioned conventional device, a wind instrument that blows an air flow from a mouthpiece provided at one end of the tube and reflects or transmits the air flow inside the tube to generate a sound wave outside the tube. Although it is suitable for imitating sounds, it is not suitable for imitating instrument sounds of stringed instruments such as violins and violas. The present invention has been made to solve the above problem, and an object thereof is to provide a musical tone waveform signal forming apparatus suitable for imitating the sound of a stringed instrument.

[Means for Solving the Problems]

In order to achieve the above object, the structural feature of the invention according to claim 1 is a circulating signal path for circulating a waveform signal,
On the circulating signal path between the first and second signal delay means, which is interposed in series in the circulating signal path, and a start control signal from the outside, and between the first and second signal delay means. In the input means for inputting each waveform signal and synthesizing and outputting the input signals, and for performing a non-linear conversion on the synthetic signal output from the input means, and for interposing each of the first and second signal delay means. This is because the tone waveshape signal forming device is constituted by the non-linear converting means for outputting on the circulating signal path. The invention according to claim 2 resides in that the non-linear conversion means of the invention according to claim 1 has a hysteresis characteristic. The invention according to claim 3 is the musical tone waveform signal forming apparatus according to claim 1, wherein a circulating waveform signal is provided in the circulating signal path between each of the first and second signal delay means. A transfer characteristic changing means for changing the transfer characteristic is provided. The invention according to claim 4 is the musical tone signal forming apparatus according to claim 1, wherein at least one of the first and second signal delay means is a variable delay means. There is provided a tone control means for changing and controlling the delay time of the waveform signal in the means according to the frequency of the tone to be generated. Further, in the invention according to claim 5 in the musical tone signal forming apparatus of the invention according to claim 1, the non-linear conversion means is constituted by a variable non-linear conversion means whose conversion characteristic can be changed, and The musical tone control means for changing and controlling the conversion characteristic of the converting means is provided.

[Operation and effect of the invention]

In the invention according to claim 1 configured as described above,
When an activation control signal from the outside is input to the input means, the control signal is guided to the circulation signal path via the non-linear conversion means, and the waveform signal on the signal path passes through the first and second signal delay means. Begins to circulate. At the same time, a part of the circulating waveform signal is input to the input means, is combined with the start control signal by the input means, and is output again on the circulation signal path via the non-linear conversion means. Become. Since the waveform signal circulating on the circulation signal path is delayed by the total delay time by the first and second signal delay means, the circulating waveform signal becomes a waveform signal having a cycle corresponding to the total delay time. In addition, a non-linear component obtained by non-linearly converting the start control signal and the circulating waveform signal from the outside by the input means and the non-linear conversion means is always added to the periodic signal. As a result, in the invention according to claim 1 in which the musical tone waveform signal is formed in this manner, the circulating signal path, the first and second signals are formed.
Since the signal delay means can better imitate the state of the oscillating wave traveling or reflected on the strings fixed at both ends, and the input means and the non-linear conversion means can better imitate the state of rubbing the middle part of the string with the bow. According to the present invention, it becomes possible to electronically form a musical sound extremely close to that of a stringed instrument. Further, in the invention according to claim 2, a hysteresis characteristic is given to the non-linear component by the non-linear conversion means. As a result, when the string is displaced (vibrated) by rubbing the string with the bow, the hysteresis characteristic due to the friction phenomenon (static friction and dynamic friction) between the string and the bow is better imitated. According to this, compared to the invention according to the first aspect, it becomes possible to electronically form a musical sound closer to a stringed instrument. In the invention according to claim 3, a desired transfer characteristic is given to the waveform signal circulating on the circulation signal path.
This better imitates the vibration characteristics of the string,
According to the invention, it becomes possible to electronically form a musical sound closer to that of a stringed instrument, as compared with the invention according to claim 1. In the invention according to claim 4, the tone control means variably controls the delay time by the first or second signal delay means in accordance with the frequency of the tone to be sounded, that is, it circulates on the circulating signal path. Since the cycle of the waveform signal is changed and controlled in accordance with the frequency of the musical sound to be generated, a musical tone waveform signal having a desired pitch can be formed. This allows
In addition to the effect of the invention according to claim 1, the musical tone signal forming apparatus according to the present invention can be applied to an electronic musical instrument or the like, and its application is expanded. Further, in the invention according to the fifth aspect, the musical tone control means controls various conversion characteristics of the non-linear conversion means, so that the formed musical tone waveform signal can be variously changed. As a result, according to the present invention, as compared with the invention according to the first aspect, various musical tone waveform signals are formed according to the types of bows and strings, changes in pressure applied to the strings, and the like.

【Example】

An example in which the musical tone signal forming apparatus according to an embodiment of the present invention is applied to an electronic musical instrument will be described below with reference to the drawings. FIG. 1 shows the entire electronic musical instrument in a block diagram. This electronic musical instrument is provided with a performance information generating section 11, a tone color information generating section 12 and a tone control signal generating section 13, and controls the tone based on the performance information from the performance information generating section 11 and the tone color information from the tone color information generating section 12. The musical tone control signal generated from the signal generating section 13 is supplied to the musical tone waveform signal forming section 20 to form a musical tone waveform signal of a rubbed string instrument such as a violin or a viola. The performance information generating unit 11 includes a keyboard composed of a plurality of keys corresponding to a scale, a key pressing detection circuit that detects whether or not each key is pressed, an initial touch detection circuit that detects a key pressing speed, and a key pressing pressure. Or, it is equipped with various circuits attached to the keyboard such as an aftertouch detection circuit for detecting the key pressing depth, and performance information such as presence / absence of key depression and key information indicating a key depressed, initial touch information, aftertouch information, etc. Is output. The timbre information generation unit 12 includes a timbre selection switch and an operation detection circuit for the switch, and outputs timbre information representing the selected timbre. The musical tone control signal generator 13 is composed of, for example, a microcomputer, a musical tone control parameter storage table, etc., and refers to the table according to the performance information and tone color information to refer to the various musical tone control signals that do not change with time and the various musical sounds that change with time. And output control signals. These tone control signals are, for example, first and second pitch signals PIT ₁ and PIT _2, which are determined by the key pressed on the keyboard and represent the pitch of the generated tone by a sum value, initial touch performance information, and aftertouch. A bow speed signal VEL which is determined by performance information and tone color information and which indicates the moving speed of a bow in a stringed instrument, a bow pressure signal PRES which indicates the pressure applied to the strings by the bow when the bow is moved, and mainly determined by tone color information. The tone color control signals TC _{1 to} TC ₅ as tone color control elements which are determined in consideration of the performance information. In the case where the electronic musical instrument is provided with other performance operating elements such as wheels and pedals operated by the player,
Performance information relating to the operation of each of these performance operators may be treated as performance information similar to the initial touch and aftertouch. Further, as the performance information generating section 11 and the tone color information generating section 12, another musical instrument, an automatic musical instrument or the like is adopted, and the musical tone control signal generating section 13 from the other musical instrument, the automatic musical instrument or the like to the musical tone information and tone color information Or the various tone control signals are formed in another musical instrument or automatic musical instrument so that the tone control signals are directly supplied to the tone waveform forming section 20. May be. The tone waveshape signal forming unit 20 has a closed loop circulation signal path 21 for circulating the tone waveshape signal corresponding to the strings of the rubbed string instrument, and in the signal path 21 delay circuits 22, 23, a low-pass filter 24, 25, multipliers 26 and 27, and adders 28 and 29 are inserted in series. The delay circuits 22 and 23 are adapted to variably control the respective delay times by the pitch signals PIT ₁ and PIT ₂ , and the pitch of the generated musical sound is almost determined by the variable control of the delay times. There is. Low pass filter 24,25
Is to simulate the vibration characteristics of various strings by changing the transfer characteristics of the circulating waveform signal.
The characteristics are switched and controlled by the tone color control signals TC ₁ and TC ₂ . The multipliers 26 and 27 shift the phase of the circulating waveform signal by "-1" by multiplying it by "-1", and realize the termination condition of the vibration wave at both fixed ends of the string. The waveform signal on the circulation signal path 21 is supplied to the adder 31 at each output side of the multipliers 26 and 27. This adder 31 constitutes an input means together with the adder 32,
The output of the adder 31 is connected to one input of the adder 32, and the bow velocity signal VEL is supplied to the other input of the adder 32. The adders 31 and 32 simulate that the contact portion of the string with the bow is displaced by the movement of the bow, and that the contact portion is displaced by the vibration wave traveling on the string. The output of the adder 32 is input to the non-linear table 43 via the adder 41 and the divider 42, and the output of the non-linear table 43 is passed through the multiplier 44 and the adders 28 and 29 to the circulating signal path 21.
It is supposed to be output above. The non-linear table 43 is for non-linearly converting the output from the adder 32 to simulate the displacement state of the string due to the movement of the bow. The input / output characteristics of the table 43 are the input values shown by the solid line in FIG. It is set in the output characteristics. That is, when the bow is rubbed against a string, when the bow speed is low, the frictional force between the bow and the string is mainly governed by the static friction coefficient, and the string speed is almost the same as the bow speed. When it becomes larger, the frictional force is mainly controlled by the dynamic friction coefficient, and the chord velocity becomes slower than the bow velocity, and this phenomenon is realized by the non-linear conversion by the non-linear table 43. The characteristic of the nonlinear table 43 is adapted to be changed controlled by tone color control signal TC _3. The bow pressure signal PRES is also input to the divider 42 and the multiplier 44. The divider 42 divides the signal input to the non-linear table 43 by the bow pressure signal PRES, and the multiplier 44 outputs the bow pressure signal PRES.
The output signal of is multiplied by the bow pressure signal PRES. These dividers
The 42 and the multiplier 44 simulate that the coefficient of friction is changed by the bow pressure applied to the strings and the non-linear characteristic shown by the solid line in FIG. 2 is changed. That is, by dividing the input signal of the non-linear table 43 by the bow pressure signal PRES, the solid line characteristic of FIG. 2 is changed to, for example, the broken line characteristic of FIG. 2, and the bow pressure signal PRES is added to the output signal of the table 43. 2 is changed to the alternate long and short dash line characteristic of FIG. 2 so that the chord velocity with respect to the arch velocity is similarly expanded or reduced according to the arch pressure by both calculations. The output of the multiplier 44 is the low-pass filter 45 and the multiplier.
It is fed back to the adder 41 via 46, and such feedback gives a hysteresis characteristic to the nonlinear conversion of the signal by the nonlinear table 43 including the divider 42 and the multiplier 44. The operation of giving the hysteresis characteristic will be specifically described. The tone control signal generation unit 13 to the multiplier 46
To a negative value, for example -0.1, the tone color control signal TC ₄ indicating the value of such -0.2 is supplied, the adder 41 subtracts the output signal of the multiplier 46 from the output signal of the adder 32 Function to supply the divider 42. FIG. 3 is a graph for explaining this hysteris characteristic, and shows the relationship between the output of the adder 41 and the output of the multiplier 41 by a chain line. For example, if the nonlinear conversion input (the output of the adder 32) increases from zero in the positive direction, the nonlinear conversion output (the output of the multiplier 44) increases proportionally along the solid line in FIG. Since a large positive value is shown near the input values X ₁ and X ₂ , the subtraction amount in the adder 41 also becomes large. Then, when the non-linear conversion input value reaches the value X ₁ , the non-linear conversion output value suddenly changes to a small value, and thereafter, as the same input value increases, the same output value gradually decreases while maintaining a small value. Decrease. On the other hand, when the non-linear input value decreases from such a state, the subtraction amount in the adder 41 becomes small because the non-linear conversion output value is small, and even if the non-linear conversion input value is the same as the above case, the input to the divider 42 is reduced. The value will show a large value. Then, the nonlinear transformation input value is the value X ₁
Only when the smaller value X ₂ is reached, the nonlinear conversion output value suddenly becomes large. The same applies when the non-linear conversion input value changes negatively, and the hysteresis characteristic is realized by this action. The low-pass filter 45 functions to prevent oscillation, and the multiplier 46 functions to adjust the feedback gain.The tone width control signal TC _{4 applied} to the multiplier 46 changes and controls the hysteresis width. It The characteristics of the low-pass filter 45 may also be changed and controlled by a tone color control signal. Further, the circulation signal path 21 is connected to the formant filter 51 at the connection position of the adder 28 and the delay circuit 23. The formant filter 51 simulates the acoustic characteristics of the body of a stringed instrument, and gives the input signal a frequency characteristic that is controlled to be switched by the tone color control signal TC ₅ and outputs it to the sound system 52. Sound system
Reference numeral 52 includes an A / D converter, an amplifier, a speaker, etc., which converts an input signal into an acoustic signal and outputs it. Next, the operation of the embodiment configured as described above will be described. When the performance information generator 11 supplies performance information such as key information, initial touch information, and aftertouch information to the musical tone control signal generator 13 in response to a key depression operation on the keyboard, the generator 13 generates Performance information and timbre information generator
Based on the tone color information supplied from 12, various control signals are output to the tone waveform forming section 20. In the tone waveshape signal forming unit 20, the adder 32 inputs the supplied bow velocity signal VEL to adder 41 and divider 42.
To the non-linear table 43, which non-linearly converts the bow velocity signal VEL and supplies it to the adders 28 and 29 via the multiplier 44. The adders 28 and 29 output the input signals to the circulating signal paths 21 and 21, respectively, and the output signals are the delay circuits 22 and 23 and the low-pass filter 24 on the circulating signal path 21.
25, begins to cycle through the multipliers 26, 27 and the adders 28, 29. In such a case, the delay times of the delay circuits 22 and 23 are controlled by the pitch signals PIT ₁ and PIT ₂ from the tone control signal generator 13, and the sum of the delay times of both delay circuits 22 and 23 is pressed on the keyboard. Since it is set and controlled to a value corresponding to the key pitch period,
The time for one circulation on the circulation signal path 21 is equal to the key pitch period, and the signal in the circulation is a waveform signal having the same key pitch period. Further, during the circulation of the waveform signal, the low-pass filters 24 and 25 are controlled by the tone color control signals TC ₁ and TC ₂ to give the waveform signal a frequency characteristic according to the characteristic of the string, and the multipliers 26 and 27 Since the phase of the same waveform signal is deviated by π to satisfy the string termination condition, the circulating signal is a better simulation of the vibration wave traveling on the string. Such a circulating waveform signal is guided to a formant filter 51, which is controlled by a tone color control signal TC ₅ to give the waveform signal a frequency characteristic simulating the acoustic characteristic of the body of a stringed instrument, thereby producing a sound. Supply to system 52. The waveform signal supplied to the sound system 52 is converted into an acoustic signal by the system 52 and is generated, so that the generated musical sound is extremely similar to the musical sound generated through the body due to the string vibration of the stringed instrument. It will be close. On the other hand, the bow velocity signal VEL described above continues to be supplied to the adder 32, and the waveform signal circulating on the circulation signal path 21 is also supplied to the adder 32 via the adder 31. The waveform signal and the bow velocity signal VEL are combined and input to the non-linear table 43. As described above, the non-linear table 43 outputs the non-linear conversion of this input signal.
And the multiplier 44 are controlled by the bow pressure signal PRES output from the tone control signal generator 13 to enlarge or reduce the non-linear conversion output according to the signal PRES (see FIG. 2), and the low-pass filter 45 and The feedback path including the multiplier 46 is controlled by the tone color control signal TC ₄ output from the tone control signal generator 13, and a hysteresis characteristic is given to the non-linear conversion output according to the signal TC ₄ (see FIG. 3). Therefore, the bow-string relationship of a stringed instrument whose coefficient of friction changes depending on the bow speed is better simulated.
The musical sound produced by 52 is very close to that of a stringed instrument. In the above embodiment, the divider 42 and the multiplier 44 are used to scale the non-linear conversion output.
A large number of non-linear tables 43 corresponding to this enlargement / reduction may be prepared and the conversion tables may be switched according to the bow pressure signal PRES. Further, although the non-linear table 43 is used to perform the non-linear conversion of the bow velocity signal VEL and the circulating waveform signal, the non-linear conversion may be realized by calculation instead of the same table. Further, in the above embodiment, the output end of the circulating waveform signal is provided between the adder 28 and the delay circuit 23, but if it is in the circulating signal path 21, the circulating waveform signal is taken out from another place. You may do it.

[Brief description of drawings]

FIG. 1 is an overall block diagram of an electronic musical instrument provided with a musical tone waveform signal forming apparatus according to an embodiment of the present invention, FIG. 2 and FIG.
The drawing is a graph showing the non-linear conversion characteristic of the embodiment of FIG. Explanation of code 11 …… Performance information generator, 12 …… Sound color information generator, 13 ……
Musical tone control signal generator, 20 ... Musical sound waveform signal generator, 21 ...
… Circulation signal path, 22,23 …… Delay circuit, 24, 25, 45 …… Low pass filter, 26, 27, 44, 46 …… Multiplier, 28, 29, 31, 32, 4
1 …… adder, 42 …… divider, 43 …… non-linear table.

Claims (5)

[Claims] 1. A circulating signal path for circulating a waveform signal, first and second signal delay means interposed in series in the circulating signal path, and a start control signal from the outside, and the first signal delay means. Input means for inputting each waveform signal on the circulating signal path between each of the first and second signal delay means and synthesizing and outputting the input signals; and performing non-linear conversion on the synthesis signal output from the input means. And a non-linear conversion means for outputting on the circulating signal path between each of the first and second signal delay means. 2. The non-linear conversion means according to claim 1,
A musical tone waveform signal forming device having a hysteresis characteristic. 3. The musical tone signal forming apparatus according to claim 1, wherein a transfer characteristic for changing a transfer characteristic of a circulating waveform signal in the circulating signal path between each of the first and second signal delay means. A musical tone waveform signal forming apparatus in which changing means are provided respectively. 4. The musical tone signal forming apparatus according to claim 1, wherein at least one of the first and second signal delay means is constituted by a variable delay means, and the delay time of the waveform signal in the variable delay means is changed. A musical tone waveform signal forming apparatus provided with a musical tone control means for changing and controlling the musical tone according to the frequency of the musical tone to be generated. 5. The musical tone signal forming apparatus according to claim 1, wherein the non-linear conversion means is composed of variable non-linear conversion means whose conversion characteristics can be changed, and the conversion characteristics of the variable non-linear conversion means are changed. A musical tone waveform signal forming apparatus provided with a musical tone control means for controlling.