JPH02300796A - Musical sound synthesizer - Google Patents

Abstract

PURPOSE:To generate a very natural percussion sound by imposing frequency modulation upon a signal which is propagated in a loop consisting of a delay circuit and obtaining a musical sound signal. CONSTITUTION:The output of an adder 1 is inputted to a filter 3 through a multi-stage delay circuit 11a and delay outputs of respective stages of the multi- stage delay circuit 11a are selected by a selector 11b and led out as a musical sound output. Therefore, when a signal is inputted to the adder 1 from outside, the signal circulates in the closed loop consisting of the adder 1 and a 1st delay means 11a and is outputted as a musical sound signal through a 2nd delay means 11a. At this time, the delay time of the 2nd delay means 11b is controlled with a modulating signal, so the signal propagated in the closed loop is frequency-modulated to obtain the musical sound signal. Consequently, the percussion sound which is rich in relality is regenerated.

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention particularly relates to a musical tone synthesis device suitable for use in synthesizing percussion instrument sounds. ``Prior art'' A device for synthesizing the musical tones of a natural instrument by operating a model obtained by applying the sound generation mechanism of a natural instrument to 1.
It is known from Publication No. 9. As a musical tone synthesizer for generating percussion instrument sounds, one having the configuration shown in FIG. 6 is known. In the same figure, I is an adder,
2 is a delay circuit, 3 (j filter), and the closed loop formed by these is a resonant circuit corresponding to the resonance system of a percussion instrument.Here, the delay time of delay circuit 2 and filter 3 The frequency characteristics of the transmission amount are determined according to the resonance characteristics and attenuation characteristics of the percussion instrument to be realized. When this musical tone synthesizer generates percussion instrument sounds, an impulse-like signal containing many frequency components is generated. Adder I
given to. This signal passes through the delay circuit 2, is attenuated by the filter 3, and is fed back to the adder 1, repeating the cycle. As a result, a signal is obtained from the adder I whose envelope is attenuated over time and in which each frequency component included in the signal changes over time. In this way, musical sounds similar to those of natural percussion instruments are generated. ``Problem to be solved by the invention'' Now, the sounding body of a percussion instrument is a physically continuous vibrating medium (for example, a single metal plate in the case of a cymbal), and when producing sound, this vibrating medium is divided into many frequency components. Vibrations containing . In this way, when vibrations containing many types of frequency components propagate in a vibrating medium, a phenomenon occurs in which the frequency components making up the vibrations interfere with each other and each frequency component is modulated. This phenomenon is particularly noticeable in cymbals and the like. However, the conventional musical tone synthesizer mentioned above is not configured to reproduce the mutual interference between the frequency components of the generated vibrations, so it is difficult to produce musical sounds that include timbre changes unique to percussion instruments or are rich in arity. There was a problem that it was not possible to synthesize. This invention was made in view of the above-mentioned circumstances, and aims to provide a musical tone synthesizer having a structure that conforms to the sound generation mechanism of actual percussion instruments, and thereby reproduce realistic percussion instrument sounds. There is. "Means for Solving the Problems" In order to solve the above problems, a first invention provides: adding means for adding and outputting a plurality of input signals, means for generating a modulated signal, and an output signal of the adding means. a first delay means which delays the signal by a predetermined time and returns it to the adding means; and a second delay means whose input is a signal propagating through the first delay means and whose delay time is controlled in accordance with the modulation signal. A signal is input from the outside to the addition means, and the output signal of the second delay means is taken out as a musical tone signal. Further, a second invention provides: adding means for adding and outputting a plurality of input signals; means for generating a modulation signal; and means for delaying an output signal of the adding means and feeding it back to the adding means. , a third delay means whose delay time in the signal transmission is controlled according to the modulation signal, and a signal is inputted to the addition means from the outside, and the output signal of the addition means or the third delay means is controlled according to the modulation signal. The present invention is characterized in that the signal propagating through the delay means is extracted as a musical tone signal. In a third aspect of the present invention, in the first aspect, the output signal of the adding means or the signal propagating through the first delay means is inputted to the second delay means as a modulation signal for delay time control. It is characterized by the fact that it is made to do so. In a fourth aspect of the present invention, in the second aspect, the output signal of the adding means or the signal propagating through the third delay means is transmitted to the third delay means as a modulation signal for delay time control. The feature is that the input can be changed as follows. In a fifth aspect of the present invention, in the third aspect, the output signal of the adding means or the signal propagating through the first delay means is band-limited and used as a modulation signal for delay time control. It is characterized by the fact that the delay means is done manually. In a sixth aspect of the present invention, in the fourth aspect, the output signal of the adding means or the signal propagating through the third delay means is band-limited; It is characterized by the fact that the modulation signal is manually input. "Operation" Part 2 According to the first invention, when a signal is input to the adding means from the outside, the signal (j) circulates through a closed loop composed of the adding means and the first delay means, and The signal is outputted as a musical tone signal via the second delay means.At this time, the delay time of the second delay means is controlled by the modulation signal, so that the signal propagating through the closed loop is frequency-modulated by the modulation signal, and the signal is output as a musical tone signal. Furthermore, according to the second aspect of the invention, when a signal is inputted to the addition means from the outside, the signal circulates through a closed loop composed of the addition means and the third delay means, and The signal that propagates is output as a musical tone signal.At this time, the delay time of the third delay means, that is, the time required for the signal to go around the closed loop, is controlled by the modulation signal, and the signal is frequency modulated by the modulation signal. Further, according to the third invention, the delay time of the second delay means in the first invention is controlled by the output signal of the addition means or the signal propagated through the first delay means. Therefore, a musical tone signal is obtained by frequency modulating a signal propagating through a closed loop composed of the addition means and the first delay means by a signal within the same closed loop. According to the invention, a signal propagating through a closed loop composed of the addition means and the third delay means is frequency-modulated by a signal within the same closed loop, and the frequency-modulated signal within the closed loop is output as a musical tone signal. According to the fifth aspect of the invention, the musical tone signal is obtained by frequency-modulating the signal propagating through the closed loop composed of the addition means and the first delay means with a signal obtained by band-limiting the signal in the same closed loop. Further, according to the sixth invention, a signal propagating through the closed loop composed of the addition means and the third delay means is frequency-modulated by a signal obtained by band-limiting a signal within the same closed loop, and the signal within the closed loop is frequency-modulated. A frequency-modulated signal is output as a musical tone signal. ``Example'' The present invention will be described in detail below with reference to the drawings.

[First Embodiment] FIG. 1 shows the configuration of a musical tone synthesizer according to a first embodiment of the present invention. This musical tone synthesis device consists of an adder I
The configuration of FIG. 6 described above is such that the output of the multi-stage delay circuit +1a is input to the filter 3 via the multi-stage delay circuit +1a, and the delayed output of each stage of the multi-stage delay circuit 11a is selected by the selector Ilb and taken out as the musical tone output. different from. Also,
In the musical tone synthesis apparatus shown in FIG. 1, the output signal of the adder 1 is input as the modulation signal m to the selector Ilb. When this musical tone synthesizer generates a percussion instrument sound, an impulse-like signal containing many frequency components is sent to the adder l.
given to. This signal passes through the multistage delay circuit 11a,
The cycle of being attenuated by filter 3 and fed back to adder l is repeated. As a result, adder I→multistage delay circuit 11a→filter 3
The envelope of the signal circulating in the closed loop formed by the above attenuates over time, and each frequency component included in the signal changes over time. On the other hand, among the outputs of each stage of the multistage delay circuit 11a, the modulation signal m
A signal corresponding to the above is selected by the selector Ilb and output as a musical tone signal. Further, the output signal of the adder 1 is inputted to the selector Ilb as the modulation signal m. Here, the output of each stage of the multi-stage delay circuit 11a is a series of sample values obtained by sampling the signal being transmitted at different points on the time axis, and the output of each stage is selected according to the modulation signal m. This process is equivalent to the process of frequency-modulating the signal transmitted by the multi-stage delay circuit 11a using the modulation signal m. In this way, a signal that is frequency-modulated by the output signal of the adder 1 on the signal propagating through the multi-stage delay circuit ILa is output as a musical tone signal. According to this embodiment, since the musical tone signal is frequency-modulated every moment by itself, it is possible to synthesize a sound that is extremely close to that of a natural percussion instrument. In the case of the circuit shown in FIG. 1, the outputs of each stage of the multistage delay circuit 11a are temporally discontinuous sample values, so if these are switched and output, there is a risk that noise will be generated in the output signal. In order to prevent this noise from occurring, for example, a linear interpolation circuit is used in place of the selector 11b in FIG. The circuit shown in FIG. 2 is a specific example of a linear interpolation circuit, and includes a delay circuit 12 having a delay time τ, multipliers 13 and 14.
, a subtracter 15, and an adder I6. When a signal r(t) is input to this linear interpolation circuit at time t, this signal is directly input to the multiplier 14 and is also delayed by the delay circuit 12 by a time τ and input to the multiplier 13. . Therefore, at time t, the multiplier 14 receives the signal f(t) at the time J, and the multiplier I
3 shows the signal r(t-τ) from the time τ before the relevant point in time.
is input. The multiplier 13 is supplied with the modulation signal m as a multiplication coefficient, and the multiplier 14 is supplied with the output signal of the subtracter 15, which is a signal obtained by subtracting the modulation signal m from the signal corresponding to the value 1. 1-m is provided as a multiplication factor. Here, a signal corresponding to a decimal value between 0 and 1 is input as the modulation signal m. Then, the adder 16 adds together the =11- output signals of the multipliers 13 and 14, resulting in a signal f(m) shown in equation (1) below.
is output. f(m)=(1-m)f(t)+m f(t-r
) --(1) In this way, the signal f(m) at the time corresponding to the modulated signal m between the signals f(t) and f(-τ) separated by the time τ is obtained by linear interpolation. and output. The input signal and modulation signal m of this linear interpolation circuit are
If the linear interpolation circuit is configured to input the output signal of the adder I of the musical tone synthesis apparatus shown in FIG. Since the frequency modulation in this case is performed continuously in time, the above-mentioned switching noise does not occur, and a high-quality musical tone signal can be obtained. [Second Embodiment] FIG. 3 shows the configuration of a musical tone synthesizer according to a second embodiment of the present invention. In this musical tone synthesis device, the output signal of the adder I is input to the filter 3 via the variable delay circuit 17. Here, the variable delay=12- delay circuit 17 is the one shown in FIG. A circuit in which the delay time can be adjusted by a modulation signal, such as a circuit combining the multistage delay circuit 11a and the selector Ilb, or a linear interpolation circuit shown in FIG. 2 is used. In this musical tone synthesis device, the delay time of the variable delay circuit 17 is controlled by the output signal of the variable delay circuit 17. That is, in this musical tone synthesis device, the total delay time of the closed loop formed by adder 1→variable delay circuit 17-filter 3 is changed according to the musical tone signal, thereby outputting a frequency-modulated musical tone signal. . Even in this case, as in the first embodiment, a realistic musical sound signal close to that of an actual percussion instrument can be obtained.

[Third Embodiment] FIG. 4 shows the configuration of a musical tone synthesizer according to a third embodiment of the present invention. This musical tone synthesis device has an adder 1
As mentioned above, the band-limited output signal of the filter 18 is applied to the variable delay circuit 17 as the modulation signal m, and the all-pass filter 19 is inserted between the variable delay circuit 17 and the filter 3. This is different from the configuration shown in FIG. In this configuration, the output signal of the adder I is band-limited by the filter 18 and used as the modulation signal m. Since the signal can be modulated, the controllability of frequency modulation is better than in the first and second embodiments. Furthermore, since the phase difference between the input signal and the output signal in the all-pass filter 19 changes depending on the signal frequency, the adder 1-variable delay circuit I
7→all-pass filter I9→filter 3 As the circulation in the closed loop formed by filter 3 is repeated, the phase difference between each frequency component of the signal changes. Then, realistic percussion sounds are generated. Either the output of the adder 1 (output I) or the output of the variable delay circuit 17 (output 2) may be selected as the outlet for the musical tone output. However, selecting output 1 has the advantage that the time from when the input signal is supplied until the musical tone signal waveform rises can be shortened.

Fourth Embodiment FIG. 5 shows the configuration of a musical tone synthesis device according to a fourth embodiment of the present invention. In this figure, SR,,SF
2. SR2,3F3. SR3 is a shift register. Each stage of these soft registers is composed of flip-flops whose number corresponds to the number of bits of transmission data, and each flip-flop is driven by a common clock. Reference numeral 21 denotes a variable delay circuit having the same configuration as that shown in the first to third embodiments. The signal input to the variable delay circuit 21 is delayed by a predetermined time and output as an output signal 2a. Further, a signal delayed by a time corresponding to the modulation signal m is output as the output signal 2b. IVIA, IVIB, IV2A, IV2B, IV3A,
rV3B is an inverting circuit, MA, MB, MA2 . MB2
．． MA3. MB3 is a multiplier, AIA, AIB, which multiplies input data by a predetermined attenuation coefficient. A2A, A2B, A3A, A3B, A123. BI23
is an adder. Here, variable delay circuit 21 and shift register SR,
, shift registers S F t and S I't 2, and shift registers SF3 and S'Rs constitute a resonant circuit, and these resonant circuits can simulate resonance phenomena in percussion instruments such as cymbals and drums. will be played. For example, once vibration occurs in a cymbal, that vibration is sustained by resonance of the non-hull. In this case, it is thought that there are a large number of vibration propagation paths in the cymbal, and therefore, the cymbal is considered to have a correspondingly large number of resonant frequencies. In this embodiment, as described above, three resonant circuits are provided to reproduce the resonance phenomenon in cymbals. In the case of this embodiment, the number of stages of flip-flops in each shift register is N + , N t ,
The delay time of the final stage output of N3 and the variable delay circuit 2I is determined in accordance with the dominant resonant frequency of the percussion instrument to be simulated. The operation of this musical tone synthesis device will be explained below. In this musical tone synthesis device, when generating a musical tone, the adder BI23
gives an impulse-like signal to This signal is passed through the adder B123 and further to the adder AI
A, A2A, A3A, variable delay circuit 21 and shift register SF2. Input to SF3. The signal input to the variable delay circuit 21 is delayed by a predetermined time, and
The signal is input to the inverting circuit IVIB and is inverted. Inverting circuit I
The output signal of VIB is delayed for a predetermined time by shift register SR, and then sent to adder AI via inverting circuit IVIA.
Returned to A. In this way, the reciprocating phenomenon of vibrations in a percussion instrument is simulated. Other transmission paths (shift registers SF', , S.R2 and SF'3.SR,
Similarly, the signal reciprocates in the loop formed by , , and . On the other hand, variable delay circuit 21 and shift register SF2.
The output signals of SF3 are sent to multipliers MA, , MA 2 , respectively.
M A 3 gives a loss coefficient α1. α2. multiplied by α3, summed by adder A123, and added by adder A1B.
, A2B, and A3B. Furthermore, the output signals of the noft registers SR, SR2, and SR3 are outputted to the multipliers M
B + , M B 2 , M B 3 are multiplied by loss coefficients β1°R3, R3, summed by adder B123, and input to adders AIA, A2Δ, A 3 A. Therefore, the signals propagating through variable delay circuit 2I and each soft register are gradually attenuated as time passes. In this way, the attenuation of one note on 71 musical instruments is simulated. Then, a musical tone signal obtained by frequency-modulating the output signal of the adder AIA by J: is output from the variable delay circuit 21 (output 2b), while a musical tone signal without frequency modulation is output from the adder Al23. I get a signal. In the above-described embodiments, a case has been described in which a signal within the musical tone synthesizer is used as a modulation signal, but it may also be supplied from outside. Furthermore, when realizing it with a digital circuit, a RAM may be used as the variable delay circuit. Furthermore, a plurality of devices having the configurations shown in the above embodiments may be assembled and the signals propagated within each device may be used as modulation signals of other devices. Further, the present invention can be realized regardless of whether it is a digital circuit or an analog circuit.
The signal processing of the present invention is performed using a DSP (digital signal processor).
It may be realized by calculation processing such as. Furthermore, an analog signal obtained by hitting a piezoelectric sensor or the like may be input to the musical tone synthesis device of the present invention. In this case, the input analog signal includes the strength of the blow, the hardness of the object to be hit,
Since information such as how to strike is included, it is possible to obtain highly realistic percussion instrument sounds similar to those of an actual percussion instrument performance. Furthermore, the present invention can be applied not only to the synthesis of percussion instrument sounds, but also to the synthesis of various natural instrument sounds or reverberant sounds. "Effects of the Invention" As explained above, according to the present invention, a musical tone signal is obtained by frequency modulating the signal propagated in a loop constituted by a delay circuit, so that it is similar to that obtained in an actual percussion instrument. The effect is that it is possible to generate percussion instrument sounds with a rich natural feel.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a musical tone synthesizer according to a first embodiment of the present invention, FIG. 2 is a diagram showing an example of the configuration of a linear interpolation circuit suitable for application to the same embodiment, and FIG. FIG. 4 is a block diagram showing the configuration of a musical tone synthesizer according to a third embodiment of the invention, and FIG. 5 is a block diagram showing the configuration of a musical tone synthesizer according to a third embodiment of the invention. FIG. 6 is a block diagram showing the configuration of a musical tone synthesis device according to an embodiment. FIG. 6 is a block diagram showing the configuration of a conventional musical tone synthesis device. ■...Adder, Ila...Multi-stage delay circuit, I
lb...Selector, 17.21...Variable delay circuit, 18...Filter, SR, SF2. SR2,
SF'3. SR. SR+A, 5F2A, 5R2A, 5F3A, SR3Δ・
...Shift register, IV IA, IV IV,
IV2A. IV 2 B, IV 3 A, IV 3 B・-
...Inverting circuit, MΔ,, M B +, M A 2. M
B2. M A 3. M B 3... Multiplier,
AIA, AIB, A2A, A2B, Δ3A, Δ313.
Δ123, Bi12...Adder.

Claims (6)

[Claims] (1) Adding means for adding and outputting a plurality of input signals, means for generating a modulation signal, and first delay means for delaying the output signal of the adding means for a predetermined time and feeding it back to the adding means. , a second delay means whose input is a signal propagating through the first delay means and whose delay time is controlled in accordance with the modulation signal; a signal is input from the outside to the addition means; A musical tone synthesizer which extracts the output signal of the second delay means as a musical tone signal. (2) Adding means for adding and outputting a plurality of input signals, means for generating a modulated signal, and means for delaying the output signal of the adding means and feeding it back to the adding means, the method comprising: and third delay means whose delay time is controlled according to the modulation signal, and a signal is inputted to the addition means from the outside, and the output signal of the addition means or the third delay means is propagated. A musical tone synthesizer that extracts a signal as a musical tone signal. (3) The output signal of the addition means or the signal propagated through the first delay means is inputted to the second delay means as a modulation signal for delay time control. 1. The musical tone synthesis device according to 1. (4) A claim characterized in that the output signal of the addition means or the signal propagated through the third delay means is inputted to the third delay means as a modulation signal for delay time control. The musical tone synthesis device according to item 2. (5) The output signal of the adding means or the signal propagating through the first delay means is band-limited and inputted to the second delay means as a modulation signal for delay time control. 4. The musical tone synthesis apparatus according to claim 3. (6) The output signal of the adding means or the signal propagating through the third delay means is band-limited and inputted to the third delay means as a modulation signal for delay time control. 5. The musical tone synthesis device according to claim 4.