JPH0954587A - Musical tone synthesizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a musical tone synthesizer capable of faithfully imitating the time changes of the force applied on strings when hammers strike the strings. SOLUTION: The respective parameters of delay information T1 to T4 , coeffts. C1 to C4 for arithmetic operation of filters, multiplying coeffts k1 to k4 and hammer initial speed signal Vh are formed in response with a sounding instruction and are applied to the respective sections. An excitation circuit consisting of an adder 551, integrators 555, 561, 566, a subtractor 556, a nonlinear circuit 557, multipliers 559, 563, 567 and a delay circuit 568 calculates a repulsive force signal F when the string striking is operated based on signals taken out of a loop circuit 520 and this signal is inputted to loop circuits 510, 510, respectively, so that the excitation signals circulate in the respective loop circuits. These circulating signals are introduced via multipliers M1 , M2 to another loop circuits, by which the crossinterferences of the respective strings are imitated. The outputs of these loop circuits are added by an adder A5 via multipliers M11 , M12 , by which the musical tone signals are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone synthesizer suitable for synthesizing a plucked musical instrument sound such as a piano sound and a plucked musical instrument sound such as a guitar sound.

[0002]

2. Description of the Related Art A musical tone synthesizing device for synthesizing a natural musical instrument sound by operating a model simulating a sounding mechanism of a natural musical instrument is known. As a musical sound synthesizer for a stringed or plucked instrument, a loop circuit including a delay circuit that simulates the propagation delay of vibration in a string and a filter that simulates acoustic loss in the string, and a plucked or struck string in this loop circuit An excitation circuit for inputting an excitation signal corresponding to the excitation vibration at this time is known. A musical tone synthesizer of this type is disclosed in, for example, Japanese Patent Publication No. 58-58679.

[0003]

Generally, a piano is provided with a plurality of strings for one key. Here, the tension of each string does not exactly match, and the pitch generated by each string is slightly deviated, and as a result, it is thought that a unique timbre unique to each piano can be obtained. Has been. Further, when observed strictly, the vibration of each string propagates to the other strings via the bridge portion, and mutual interference occurs between the strings, and as a result, a sound with a slight undulation is generated. This phenomenon is observed not only in the piano but also in playing the guitar and the violin. That is, in a guitar or a violin, the adjacent string resonates with the vibration of the string that is actually played, and a musical sound with a good resonance is generated. However, the conventional musical sound synthesizing device does not take into consideration the plurality of subtle deviations of the excited characteristics as described above, nor does it take into consideration mutual interference between the strings.

Further, in a piano, the repulsive force of the string changes depending on the amount of displacement of the string, and the force applied to the string by the hammer changes depending on the speed of the hammer. The force applied to will change from moment to moment in the relationship between the amount of displacement of the string and the speed of the hammer. However, in the conventional tone synthesizer, only the excitation signal is generated according to the predetermined parameter,
No consideration was given to the phenomenon in the actual piano as described above.

The present invention has been made in view of the above circumstances, and provides a musical tone synthesizer capable of faithfully imitating the time change of the force applied to a string when a hammer strikes the string. With the goal.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a parameter generating means for generating a parameter corresponding to a desired musical tone, a plurality of loop means including at least a delay means, and a signal taken out from each loop means are used in another loop. Means for inputting to the means, and in response to a sounding instruction, an excitation signal is generated based on the parameter generated from the parameter generating means and the signal extracted from the loop means, and the excitation signal is generated. Excitation means for inputting a signal to at least one loop means of the plurality of loop means.

According to the above construction, the exciting means in response to the sounding instruction generates an exciting signal based on the parameter generated by the parameter generating means and the signal taken out from the loop means corresponding to a desired musical tone, and the exciting signal is generated. The signal is input to at least one of the loop means constituting the multi-loop coupling means, and the signal is circulated in this loop means. Further, the signal circulating in each loop means is introduced into another loop means via the coupling means, mutual interference between the loop means is performed, and a frequency corresponding to a pitch of a desired musical tone is generated from these loop means. The signal is obtained. When there is a deviation in the delay time for a signal to make a loop through each loop means, a musical tone having a undulation based on the deviation is generated.

[0008]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a block diagram showing the arrangement of a musical sound synthesizer according to the first embodiment of the present invention. Reference numeral 1 is a keyboard for an electronic musical instrument, and 2 is a key information generator. Here, when a key depression operation is performed on the keyboard 1, the key code information KC of the depressed key, the key-on signal KON indicating that the key is depressed, and the initial touch information IT indicating the strength at the time of depressing the key. Is output from the key information generating unit 2, and when the pressed key is released, the key-off signal KOFF is output.

Reference numeral 3 denotes a string system parameter forming section, which comprises a parameter memory 32 realized by a microprocessor 31 and a ROM (read-on memory) as shown in FIG. The microprocessor 31 uses the key code information KC, the key-on signal KON and the key-off signal KOF.
F is inputted, the delay information corresponding to the key code data KC T ₁ through T _4, to generate a filter operation coefficient C ₁ -C ₄ and the multiplication coefficient k ₁ to k _6. As shown in FIG. 3, each of these pieces of information is stored in the parameter memory 32. When the key-on signal KON is asserted, the information corresponding to the key code information KC is read by the microprocessor 31. It is supposed to be output. The meanings of these pieces of information T _{1 to} T ₄ , C _{1 to} C ₄ and k _{1 to} k ₆ will be described later.

Reference numeral 4 denotes a hammer system parameter forming section, the structure of which is shown in FIG. In the figure, the set-reset flip-flop 43 is set by the key-on signal KON, and the Q output of the flip-flop 43 is taken into the delayed flip-flop 44 by the clock φ generated at a predetermined cycle, and the Q of the flip-flop 44 is changed.
The flip-flop 43 is reset by the output. Further, the AND gate 42 has a clock φ.
And the Q output of the flip-flop 43 is input, and AN
The output of the D gate 42 is R as an output enable signal OE.
Input to OM41. The ROM 41 stores information indicating the hammer speed corresponding to the initial touch information IT.

However, according to the hammer system parameter forming section 4, after the key-on signal KON is asserted,
The ROM 41 is enabled for a period corresponding to one cycle of the clock φ, and the hammer speed signal Vh corresponding to the initial touch information IT is output.

Reference numeral 5 denotes a musical tone forming section, the structure of which is shown in FIG. The musical tone forming section 5 forms musical tones of a two-string piano. In FIG. 5, a filter 511, an adder 512, a delay circuit 513, a multiplier 514, and an adder 5
15, filter 516, adder 517, delay circuit 518
And a loop circuit 510 including a phase inversion circuit 519,
Further, the round-trip propagation of vibration in each string is simulated by the loop circuit 520 having the same configuration as the loop circuit 510.

The delay circuits 513 and 518 are delay circuits whose delay time is variable and which simulate the propagation delay of the vibration in the first string. The delay circuits 513 and 518 depend on the delay information T ₁ and T ₂ generated by the string system parameter forming section 3. The delay time is controlled. Similarly, the delay circuit 523 corresponding to the second string
And 528 are provided with delay information T ₃ and T ₄ .
Such a delay circuit with a variable delay time can be realized by, for example, a shift register that delays an input signal and a selector that selects and outputs a delay output of each stage of the shift register according to delay information.

In the case of an actual piano, the tension of each string corresponding to one key is not always the same, and a detune effect resulting from this appears. Therefore, in consideration of the detune effect that may occur in a normal piano, the total delay time of each of the loop circuits 510 and 520 should be a value that substantially corresponds to the pitch and be slightly deviated from each other. delay information T ₁ through T ₄ are set.

Filters 511 and 516, filter 5
21 and 526 are simulations of acoustic loss in each string. Usually, the higher the frequency, the greater the loss, so these filters are implemented by low-pass filters. The filters 511 and 516 and the filters 521 and 526 have filter calculation coefficients C ₁ and C ₂ , C generated by the string parameter forming unit 3, respectively.
₃ and C ₄ are given respectively, and the filter operation corresponding to the key code information KC is performed based on these.

The phase inversion circuit 519 and the multiplier 514,
The phase inversion circuit 529 and the multiplier 524 are provided to simulate a phase inversion phenomenon that occurs when vibration is reflected at both ends of each string, and are provided to the multipliers 514 and 524 during the generation of a musical tone. Are given by the string system parameter forming unit 3 with negative multiplication coefficients k ₃ and k ₄ , respectively. Further, when the key-off signal KOFF is generated in response to the key release, the multiplication coefficients k ₃ and k ₄ are switched by the string-system parameter forming unit 3 to a value having a small absolute value, and the musical sound is rapidly attenuated.

Delay circuit 513 in loop circuit 510
Output signal of the multiplier M₂ Multiplication coefficient k₂ Multiplied by
Is introduced into the loop circuit 520 via the adder 525.
Is done. Similarly, the delay circuit 5 in the loop circuit 520
The output signal of 23 is the multiplier M ₁(Multiplication coefficient k₁) And addition
It is introduced into the loop circuit 510 via the calculator 515.
According to such a configuration, the loop circuits 510 and 52
Signals are exchanged between 0 strings, and the strings
Wataru is simulated. Each multiplication coefficient k₁, K₂Is 1
Is a fairly small value, and mutual interference to be achieved
Is set according to the degree of.

Next, the excitation circuit 550 will be described. The excitation circuit 550 generates an excitation signal corresponding to the excitation vibration given to the strings by the hammer. The outputs of the filters 521 and 526 in the loop circuit 520 are input to the adder 551, and the string speed signal Vs ₁ corresponding to the speed of the string is output from the adder 551. The string velocity signal Vs ₁ is multiplied by the coefficient sadm by the multiplier 552. The coefficient sadm will be described later.

The output signal sadmVs ₁ of the multiplier 552 is integrated by an integrating circuit 555 including an adder 553 and a one-sample period delay circuit 554. Then, from the integrating circuit 555, the reference line RE of the string SP of the piano shown in FIG.
A string displacement signal x corresponding to the displacement from F is output, and the string displacement signal x is input to one input terminal of the subtractor 556.
Here, the hammer displacement signal y corresponding to the displacement of the hammer HM (see FIG. 6) output from the integrator 566 described later is input to the other input terminal of the subtractor 556. Then, the subtractor 556 outputs a relative displacement signal y−x corresponding to the relative displacement between the hammer HM and the string SP.

Here, when the strings SP bite into the hammer HM, y-x becomes positive, and a repulsive force corresponding to the biting amount works between the strings SP and the hammer HM. On the other hand, the string S
When the hammer HM of P is only lightly touched or when the hammer HM is separated from the string SP, y−x is 0 or negative and the repulsive force is 0.

The non-linear circuit 557 calculates a repulsive force signal F corresponding to the repulsive force between the string SP and the hammer HM on the basis of the relative displacement signal y-x. For example, a quadratic curve as shown in FIG. ROM storing a table of nonlinear functions such as
Has been realized.

The repulsive force signal F is added to the adders 512 and 517 of the loop circuit 510 and the adders 522 and 522 of the loop circuit 520.
Input to 527. Originally, the repulsive force signal F should be multiplied by a coefficient corresponding to the resistance to the speed change of the string SP to calculate the speed change amount of the string SP, and 1/2 of that should be input to each loop circuit 510 and 520. However, in the present embodiment, the resistance to the speed change is considered by adjusting the multiplication coefficient sadm described above.

Further, the repulsive force signal F is multiplied by the coefficient fadm by the multiplier 567, and the string speed signal βs corresponding to the speed change given to the string SP by the hammer HM is obtained. The chord velocity signal βs is delayed by one sample period by the delay circuit 568 and input to the integrator 555. By doing so, a phenomenon in which the strings SP are displaced by being hit by the hammer HM is simulated.

The repulsive force signal F is input to the multiplier 559. Here, the reciprocal of the inertia amount M of the hammer HM, −1 / M, is given to the multiplier 559 as a multiplication coefficient. As a result, the multiplier 559 outputs the hammer acceleration signal α corresponding to the acceleration of the hammer HM. The hammer acceleration signal α is integrated by an integrator 562 including an adder 560 and a delay circuit 561, and the integrator 562 outputs a hammer speed signal β corresponding to the speed change of the hammer HM. Then, this hammer speed signal β is applied to the multiplier 563.
Is multiplied by a predetermined damping coefficient by way of, and is input to the integrator 566 composed of the adder 564 and the delay circuit 565 together with the hammer initial velocity signal Vh generated by the hammer system parameter forming unit 4, and from the integrator 566. The hammer displacement signal y described above is output.

The output signals of the delay circuits 513 and 523 in each loop circuit are respectively supplied to multipliers M ₁₁ and M _{12 respectively.}
Is multiplied by a predetermined multiplication coefficient and added by the adder A ₅ , and output as a musical tone signal of a direct sound generated by the vibration of the string SP. This musical tone signal is given a resonance effect by a filter 6 simulating a piano soundboard, then converted into an analog signal by a D / A (digital / analog) converter (not shown), and sounded as a musical tone from a speaker 7. It

The operation of this embodiment will be described below. In the initial state before striking the strings, the hammer HM is separated from the strings SP, and the relative displacement signal y−x has a negative value in the tone forming unit 5, so that the repulsion force signal F is 0. There is. The delay circuits 554, 561 and 565 are all reset to 0.

When a key is pressed on the keyboard 1, the key information generator generates the key code information KC and the key-on signal K.
ON and initial touch information IT are output. Then, the key code information KC is output from the string parameter forming unit 3.
Corresponding to the delay information T _{1 to} T ₄ and the filter calculation coefficient C ₁
.About.C ₄ and multiplication coefficients k _{1 to} k ₆ are output and set in the corresponding parts of the tone forming section 5, the hammer system parameter forming section 4 calculates the hammer initial speed according to the initial touch information IT, and the clock φ The hammer initial velocity signal Vh is output for a period corresponding to one cycle of the above and is given to the integrator 566 in the musical tone forming section 5.

As a result, the integrated value of the integrator 566, that is, the hammer displacement signal y changes from negative to positive with the lapse of time. Since the string displacement signal x is 0 during this period,
The relative displacement signal y−x is a negative value (hammer HM and string SP
(Corresponding to the state where and are separated), the repulsion force signal F is 0 and the hammer speed signal β is 0, as shown in FIG. Therefore,
The integrator 566 integrates only the hammer initial velocity signal Vh.

When the relative displacement signal y-x exceeds 0 (corresponding to the state in which the hammer HM collides with the string SP) and becomes a positive value, the non-linear circuit 557 produces a magnitude corresponding to the relative displacement signal y-x. The repulsive force signal F of is output. Then, the repulsive force signal F is multiplied by the coefficient −1 / M by the multiplier 559 to calculate the hammer acceleration signal α (negative value), and the integrator 562 integrates the hammer acceleration signal α to obtain the hammer speed. The signal β is determined. Here, since the hammer speed signal β has a negative value, in the integrator 566, the initial speed signal Vh is decelerated by the amount of the hammer speed signal β and integration is performed, and the increase in the hammer displacement signal y changes with time. Gradually becomes dull. Further, a string velocity signal βs corresponding to the hammer repulsion signal F is generated and integrated by the integrator 555,
The string displacement signal x changes.

During this period, the hammer displacement signal y increases in the positive direction (the moving direction of the hammer HM such that the string SP bites), and the relative displacement signal y-x increases. As a result, the repulsion force signal F increases as shown by the arrow F ₁ in FIG. 7.

As a result of the acceleration signal α being output in accordance with the repulsive force signal F thus generated, the hammer speed signal β increases in the negative direction (the direction in which the hammer HM moves away from the string SP). Then, when the absolute value of the hammer speed signal β exceeds the initial speed signal Vh and the speed direction of the hammer HM reverses in the direction away from the string SP, the hammer displacement signal y changes in the negative direction. Then, the relative displacement signal y−x gradually decreases, and the repulsion force signal F decreases accordingly (arrow F ₂ ). Then, the relative displacement signal y−x <0, that is, the hammer HM is separated from the string SP, and the string striking operation ends.

In this way, the repulsive force signal F during the string striking operation is calculated, and the repulsive force signal F contributes to the change in speed given to the string SP by the hammer HM, that is, as excitation signals, the loop circuits 510 and 520. Entered in. Then, in each of the loop circuits 510 and 520,
The input excitation signal circulates. In addition, the loop circuit 51
The signal that circulates through 0 is sent to the loop circuit 5 through the multiplier M _2.
20. Similarly, a signal is introduced from the loop circuit 520 to the loop circuit 510, and mutual interference of each string is simulated.

The output signals of the loop circuits 510 and 520 are passed through multipliers M ₁₁ and M ₁₂ , respectively, and then added by an adder A ₅ to form a musical tone signal. A resonance effect is imparted by the speaker 7, and the speaker 7 produces a musical sound.

[Second Embodiment] FIG. 8 shows a tone forming section of a tone synthesizer according to a second embodiment of the present invention. This tone forming section forms a tone of a piano provided with three strings for one key, and has a loop circuit 53 corresponding to the third string in the configuration of FIG. 5 described above.
0 is provided. Further, in order to simulate the mutual interference of the three strings, the loop circuit 530 and the other loop circuits 510 and 520 have multipliers M _{6 to} M ₉ (multiplication coefficients k ₆ to
k ₉ ).

[Third Embodiment] FIG. 9 shows a tone forming section of a tone synthesizer according to a third embodiment of the present invention. This tone forming section is provided with loop circuits 510 and 52.
The point that the delay circuits 601 and 602 are used instead of the multipliers M ₁ and M ₂ as means for coupling 0 is different from the configuration of FIG. 5 described above. According to this configuration, the vibration of each string passes through the bridge portion, so that the operation when the phase changes and propagates to another string is faithfully simulated.

[Fourth Embodiment] FIG. 10 shows a fourth embodiment of the present invention.
1 is a diagram showing a tone forming unit of a tone synthesizer according to an embodiment. This tone forming section is provided with loop circuits 510 and 5
5 is different from the above-described configuration in FIG. 5 in that filters 603 and 604 simulating the frequency characteristic of the loss in the bridge portion are used instead of the multipliers M ₁ and M ₂ as means for coupling 20. According to this configuration, the vibration of each string passes through the bridge portion, so that the operation when the spectrum is transformed and propagated to another string is faithfully simulated.

[When simulating open string resonance]
Each of the embodiments described above is a simulation of hitting a plurality of strings with a hammer like a piano, but it is possible to simulate the resonance of an open string in a guitar, a violin or the like with almost the same configuration. You can
In this case, the excitation signal is not input to all the loop circuits, but the excitation signal is input only to one loop circuit in which the delay time corresponding to the desired pitch is set. Also,
Other loop circuits that do not input the excitation signal set the delay time according to the pitch of the open string next to the string actually played. By doing so, a tone signal corresponding to a desired pitch is formed in the loop circuit for inputting the excitation signal, and this tone signal is input to another loop circuit to be generated by the open string. A resonance tone signal is formed.
In addition, in the first and second embodiments described above,
By inputting the excitation signal to only one loop circuit, the effect of the unacorda pedal of the piano can be obtained.

In the embodiment described above, the case where the musical tone synthesizer is realized by a digital circuit has been described, but it is also possible to realize the musical tone synthesizer by an analog circuit, and an effect similar to that achieved by the digital circuit can be obtained. can get. It is also possible to use a waveguide as a loop circuit including a delay circuit.

Also, the loop circuit may be provided in a required number according to the number of strings to be simulated. Also, FIG.
With respect to the above configuration, loop circuits corresponding to all open strings other than the strings to be actually struck may be provided, and these loop circuits may be coupled to the loop circuits 510 and 520. By doing this, a unique sound when the damper pedal is depressed is simulated.

[0040]

As described above, according to the present invention, the force applied to the string is based on the signal corresponding to the displacement amount of the string extracted from the loop means and the parameter corresponding to the speed of the hammer. Since the excitation signal corresponding to is generated, it is possible to faithfully imitate the time change of the force applied to the string from when the hammer starts striking the string to when the striking ends.

Further, according to the present invention, a plurality of loop means are provided, the loop means are coupled by the coupling means, and the excitation is performed based on the parameter generated by the parameter means and the signal extracted from the coupled loop means. Since the signal is generated, the influence of multiple strings stretched on one hammer in the piano is also taken into consideration, and the time change of the force exerted by the hammer on the strings is made more faithful. The effect of being able to imitate is obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a musical sound synthesizer according to a first embodiment of the present invention.

FIG. 2 is a string system parameter forming unit 3 in the same embodiment.
FIG. 3 is a block diagram showing the configuration of FIG.

FIG. 3 is a diagram showing stored contents of a parameter memory 32 in the same embodiment.

FIG. 4 is a block diagram showing a configuration of a hammer system parameter forming unit 4 in the same embodiment.

FIG. 5 is a block diagram showing a configuration of a musical sound forming unit 5 in the same embodiment.

FIG. 6 is a diagram showing a state of a hammer HM and a string SP when the string is struck, which is simulated by the embodiment.

FIG. 7 is a diagram exemplifying a change in the repulsive force signal F with respect to the relative displacement signal y−x in the same embodiment.

FIG. 8 is a block diagram showing a configuration of a tone forming section of a tone synthesizer according to a second embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a tone forming section of a tone synthesizer according to a third embodiment of the present invention.

FIG. 10 is a block diagram showing a configuration of a tone forming section of a tone synthesizer according to a fourth embodiment of the present invention.

[Explanation of symbols]

3 String system parameter forming unit 4 Hammer system parameter forming unit 5 Musical sound forming unit 510, 520, 530 Loop circuit 550 Excitation circuit 601, 602 Delay circuit 603, 604 Filter M ₁ , M ₂ , M _{6 to} M ₉ Multiplier

Claims (1)

[Claims] 1. A parameter generating means for generating a parameter corresponding to a desired musical tone, a plurality of loop means including at least a delay means, and a coupling means for inputting a signal extracted from each loop means to another loop means. In response to the sounding instruction, an exciting signal is generated based on the parameter generated from the parameter generating means and the signal extracted from the loop means, and the exciting signal is generated from the plurality of loop means. A musical sound synthesizing apparatus comprising: an exciting means for inputting to at least one loop means.