JP2940011B2 - Music synthesizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical sound synthesizer suitable for use in synthesizing musical sounds of a stringed instrument, a plucked instrument, a bowed instrument, a percussion instrument, and the like. Conventional technology Conventionally, as a tone synthesizer, a waveform memory system that PCM-encodes various musical sound waveforms of a natural musical instrument and records it in a waveform memory, etc., and reads a waveform corresponding to performance information from the waveform memory and reproduces it Are generally known. However, natural musical instruments generate a wide variety of musical tones depending on the performance situation. For example, in wind instruments and the like, the timbre changes variously due to a change in blowing pressure. If it is intended to generate many of these musical tone waveforms by a musical tone synthesizer of a waveform memory type, an extremely large storage capacity is required for the waveform memory, so that it is impossible to realize it. Also,
A method of combining or modulating a plurality of musical sound waveforms to realize various musical sound waveforms is also conceivable.
In this case, too, the amount of calculation becomes extremely large, and it is impossible to realize. Therefore, a musical sound synthesizer that synthesizes musical tones by operating an electric model simulating a sounding mechanism of a natural musical instrument has been proposed. For example, as a musical sound synthesizer of a stringed instrument sound such as a piano, there is well known a structure in which a delay circuit simulating a propagation delay of vibration in a string and a low-pass filter simulating acoustic loss in the string are connected in a closed loop. ing. In this type of musical sound synthesizer, a signal (for example, an impulse) corresponding to an impact when a hammer strikes a string is input to a closed loop, and the closed loop is brought into a resonance state. Then, a signal circulating in the closed loop is extracted as a tone signal.
In this way, the phenomenon in which the strings of the piano are excited by being struck by a hammer to generate standing wave vibrations is faithfully reproduced, and the musical tones generated by the standing wave vibrations of the strings being directly radiated to the surroundings (hereinafter, referred to as "tones"). , Called a direct sound for the sake of convenience of the musical sound). However, an actual natural musical instrument has a resonator (for example, a soundboard in a piano, a box in a guitar), and a resonance is generated by the resonator resonating directly with the sound. A tone synthesizer capable of reproducing a resonance sound together with a direct sound includes a direct sound waveform memory in which a sound waveform of the direct sound is recorded, and a resonance sound waveform memory in which a resonance sound waveform is recorded. A system in which a direct sound waveform and a resonance sound waveform corresponding to information are read out and superimposed and output is disclosed in, for example, Japanese Patent Publication No. 1-15074. [Problems to be Solved by the Invention] By the way, in a stringed musical instrument such as a piano, an impact when a string is struck by a hammer propagates to a soundboard, and a resonance sound is generated in response to the impact. Also, in a plucked string instrument such as a guitar, a shock given to a string by a pick or a claw is transmitted to a box via a bridge, and a resonance sound is generated in response to the shock. That is, in an actual natural musical instrument, the direct sound from which the standing wave vibration of the sounding body is directly radiated, the resonance sound of the direct sound generated by the resonator, and the impact applied to the sounding body when driving the sounding body Are transmitted (hereinafter referred to as "transient sounds" for convenience), and a mixture of these sounds is heard as a musical sound. However, conventionally, there is no musical tone synthesizer capable of synthesizing such various transient sounds, and therefore, there has been a problem that realistic natural musical instrument sounds cannot be synthesized. In addition, a method has been attempted in which a transient sound generated from an instrument is extracted and recorded in a waveform memory, and a direct sound obtained by synthesis and a resonance sound of the direct sound are superimposed and reproduced. Although it is technically difficult and requires a lot of labor, there is a problem that a satisfactory transient sound cannot be easily obtained. In particular, when trying to reproduce a transient sound by a sound source based on a recording / reproducing method such as PCM, the quality of the sound largely depends on the recording technique, and in some cases, the transient sound may be annoying. The present invention has been made in view of the above-described circumstances, and has as its object to provide a musical sound synthesizer that can easily reproduce a musical sound including a transient sound generated from an actual natural musical instrument. Means for Solving the Problems The present invention is a means in which a drive signal corresponding to performance information and a drive signal generating means for generating the drive signal, and a delay means for delaying an input signal are connected in a closed loop, wherein the drive signal To the closed loop to output a signal circulating through the closed loop as a tone signal, and a first resonance for giving a resonance effect to the tone signal and outputting a first resonance signal. Means, a second resonance means for imparting a resonance effect to the drive signal and outputting a second resonance sound signal, and converting the tone signal and the first and second resonance sound signals in accordance with performance information. Output means for mixing and outputting. [Operation] According to the above configuration, a drive signal corresponding to an impact given to the sound system at the time of performance is generated by the drive signal generation means based on the performance information. In the musical sound forming means, a drive signal is input to a closed loop including a delay, and a signal circulating through the closed loop is output as a musical sound signal. Then, a resonance effect is given to the musical sound signal by the first resonance means, and a first resonance sound signal is generated. In addition, the second resonance means imparts a resonance effect to the drive signal used to generate the musical tone signal,
Is generated. Then, the tone signal and the first and second resonance signal are mixed and output according to the performance information. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a musical tone synthesizer for piano sounds according to an embodiment of the present invention. The tone control circuit 1 shown in FIG. 1 generates various control information corresponding to operation information input from the outside. The control information controls the operation of the entire apparatus. The musical sound forming circuit 2 is a circuit for forming a direct sound corresponding to the operation information, and includes an adder 2a, a delay circuit 2b for simulating a propagation delay of vibration in a string, and a filter 2c for simulating acoustic loss of a string. This is realized by a closed loop circuit. The drive signal generating circuit 3 has a waveform ROM (read only memory). The waveform ROM has a signal waveform corresponding to an impact when a hammer strikes a string (for example, many frequency components are used as the signal waveform). Is used, and a time-series digital signal in which PCM coding is performed is stored. When a tone is generated, when a key-on signal KEYON is supplied from the tone control circuit 1, digital signals are sequentially read from the waveform ROM and supplied to the tone forming circuit 2 and the resonance circuit 4 as an impact signal IP. In the tone generating circuit 2, the shock signal IP is added to the adder 2a →
The circuit circulates through a closed loop including the delay circuit 2b and the filter 2c.
This closed loop has a first-order resonance frequency corresponding to the reciprocal of a delay time required for a signal to make a round of the closed loop, and 1
It operates as a resonance circuit having a higher-order resonance frequency that is an integral multiple of the next resonance frequency. When the drive signal circulates through the closed loop, the resonance frequency components in the drive signal are emphasized. Here, the delay circuit 2b is realized by, for example, a shift register capable of switching the number of stages, and the delay time is switched by the key code information KC supplied from the musical tone control circuit 1. In this way, the time required for the signal to make a complete loop through the closed loop, that is, the primary resonance frequency of the musical tone is switched corresponding to the string. Also, filter 2c
Is usually realized by a low-pass filter. Here, the strings attached to the piano have different frequency characteristics of the vibration damping rate.
The tone color parameter TN corresponding to the string is given to 2c, and the filter calculation coefficient in the filter 2c can be switched according to the tone color parameter. Thus, the dry signal SDRY of the pitch and tone specified by the tone control circuit 1 is generated. In addition, as the tone forming circuit 2,
In addition to the above-described configuration, for example, an FM sound source or a PCM sound source may be used. Each of the resonance circuits 4a and 4b is a circuit that performs signal processing corresponding to the resonance operation of the sound board of the piano. For example, the resonance circuits 4a and 4b are formed by a closed loop circuit including a delay circuit and a filter as used in the above-described tone generation circuit 2. Is achieved.
In the resonance circuit 4a, a resonance effect is given to the direct sound signal SDRY, and a resonance sound signal RDRY corresponding to a resonance sound with respect to the standing wave signal of the string is generated. In the resonance circuit 4b, a resonance effect is given to the shock signal IP, and a transient sound signal STRN corresponding to the resonance sound of the shock given to the string by the hammer is output. Generally, the soundboard of a piano has many resonance frequencies,
Accordingly, by connecting a plurality of closed loop circuits having different resonance frequencies in parallel, it is possible to realize the resonance circuits 4a and 4b that faithfully reproduce the acoustic characteristics of the sound board of the piano. However, the impact from the hammer is transmitted mainly to the soundboard through the frame and the strings, whereas the vibration energy of the strings is transmitted mainly to the soundboard through the bridge. Thus, it is difficult to provide an appropriate resonance effect to vibrations having different propagation paths by using a single resonance circuit. Therefore, in this musical sound synthesizer, a resonance sound signal RDRY corresponding to the standing wave vibration of the string and a transient sound signal corresponding to the shock given to the string
The STRN is generated by separate resonance circuits 4a and 4b, respectively. Note that a configuration example of the resonance circuits 4a and 4b will be described later. The mixing circuit 5 includes multipliers 5a, 5b, 5c and an adder 5d. The multiplier 5a is direct sound signal SDRY input, multiplication coefficient gamma ₁ supplied from the tone control circuit 1 is multiplied. Also, the multiplier 5b, the resonance sound signal RDRY outputted from the resonance circuit 4a is input, multiplication coefficient gamma ₂ supplied is multiplied by the tone control circuit 1. Also, the multiplier 5c, the transient sound signal STRN output from the resonance circuit 4b is inputted, the multiplication coefficient gamma ₃ supplied from the tone control circuit 1 is multiplied. Then, the respective multiplication results are added by the adder 5d and output as a tone signal. Hereinafter, the operation will be described on the assumption that a keyboard unit is connected to the musical sound synthesizer to form an electronic musical instrument with a keyboard. When a key operation is detected in the keyboard unit, key code information KC and tone color parameter TN for specifying a pitch are output from the musical tone control circuit 1, and the delay circuit 2b of the musical tone forming circuit 2 is operated in accordance with the control information. The delay time setting and the filter calculation coefficient of the filter 2c are set. Next, the key-on signal KEYON is output from the tone control circuit 1. As a result, the drive signal generation circuit 3 is driven, and the tone generation circuit 2 generates a direct sound signal SDRY. Then, a resonance signal RDRY for the dry signal SDRY is generated by the resonance circuit 4a, and a transient sound signal for the impact signal IP is generated by the resonance circuit 4b. Then, the dry signal SDRY, the resonance signal RDRY, and the transient sound signal STRN are mixed by the mixing circuit 5 and output as a tone signal. In the above operation, the multiplication coefficient γ in the mixing circuit 5
₃ is set as described below. That is, generally, in the case of a piano, as the become treble, since transient sound is emphasized, according tone pitch increase, the multiplication coefficient gamma ₃ with increasing the treble is set to a large value. In this way, a natural sound is generated in which the transient sound when the string is struck by the hammer is mixed in a well-balanced manner according to the pitch.
Further, when information indicating a touch at the time of striking a key of a piano is input, and a transient sound is emphasized when the touch is strong, a musical tone with much more reality can be obtained. Note that the tone generation start initially stressed transient sound by setting the multiplication coefficient gamma ₃ to a larger value, the multiplication factor over time gamma
₃ may be smoothly changed to a small value to gradually attenuate the transient sound. By doing so, a musical sound with a more natural feeling is generated.

[Configuration example of resonance circuit]

FIG. 2 is a block diagram showing a configuration example of the resonance circuit 4 in the above embodiment. However, the resonance circuit shown in FIG. 2 is configured to have an output L for the left channel and an output R for the right channel in consideration of the stereo reproduction. Therefore, when this resonance circuit is applied to the above embodiment, a mixing circuit corresponding to each of the left channel output L and the right channel output R and mixing with the dry signal is provided, or one of the left and right mixing circuits is provided. Use the channel output of This resonance circuit includes multipliers 61 to 6 as shown in FIG.
4. It comprises closed loop circuits 71 to 74, adders 81 and 82, and all-pass filters 91 and 92. The closed loop circuits 71 to 74 simulate the resonance characteristics of a piano soundboard, and each of the closed loop circuits 71 to 74 has different resonance characteristics. Therefore, this resonance circuit has, as resonance frequencies, the primary resonance frequency of each of the closed loop circuits 71 to 74 and higher-order resonance frequencies such as secondary, tertiary, and so on. The closed loop circuit 71 includes an adder 171, a delay circuit 172, an all-pass filter 173, and a well-known low-pass filter 1.
Consists of 74. Here, the all-pass filter 17
The phase delay of 3 changes according to the frequency, and in the closed loop circuit 71, a resonance characteristic having an inharmonic overtone structure in which the higher-order resonance frequency is not an integral multiple of the first-order resonance frequency is obtained. . Then, when a signal is input to the closed loop circuit 71 via the multiplier 61, each of the above-mentioned inharmonic resonance frequency components is selected from the input signals, and circulates in the closed loop while being attenuated by the low-pass filter 174. . The resonance characteristics of a closed loop circuit using such an all-pass filter are described in, for example,
-28274. Then, the closed loop circuit 71 outputs the circulating signal to the delay circuit.
The output from each delay output terminal having a different delay time at 172 is output from multiplier 172a and 172b, respectively.
And 82. The other closed loop circuits 72 to 74 have the same configuration, and each has a different delay phase.
A set of signals is output and input to adders 81 and 82, respectively. The output signals of the adders 81 and 82 are output as an output signal L for the left channel and an output signal R for the right channel via the all-pass filters 91 and 92, respectively. Note that, as the all-pass filters 173, 91 and 92, those having a conventionally known configuration shown in FIGS. 3 (a) to 3 (d) are used. According to this resonance circuit, each of the closed loop circuits 71 to 74
In addition to the following different resonance frequencies, each resonance characteristic is non-harmonic, so that a very large number of resonance frequencies of an actual piano soundboard can be realized. Further, since two sets of signals having different phases are taken out from the closed loop circuits 71 to 74 and output as the left channel output L and the right channel output R, the reverberation effect on the input signal is reduced. A wide musical tone is generated. In the above-described embodiment, the case of synthesizing a piano sound has been described as an example. However, with the same configuration, it is possible to synthesize musical sounds of many kinds of natural musical instruments in addition to plucked string instruments such as a guitar. When a musical sound synthesizer for a guitar is configured, a signal corresponding to an impact when directly hitting a box may be input to the resonance circuit 4 in the above embodiment. In this way, for example, when playing a flamenco guitar,
A transient sound generated by hitting the box can be generated. Also, according to this musical sound synthesizer, for example,
As a resonator of a piano, it can be applied to generate a sound that cannot be generated by a natural musical instrument, such as a musical sound when a guitar box is connected instead of a soundboard. Further, the musical sound synthesizer is not limited to the digital circuit as described above, but can also be realized by an analog circuit, and can of course be realized by arithmetic processing by a DSP (digital signal processor). [Effects of the Invention] As described above, according to the present invention, a drive signal generating means for generating a drive signal corresponding to performance information, and a delay means for delaying an input signal are connected in a closed loop. Inputting the drive signal to the closed loop,
Tone generating means for outputting a signal circulating in the closed loop as a tone signal, first resonance means for imparting a resonance effect to the tone signal and outputting a first resonance signal, and Second resonance means for giving a resonance effect and outputting a second resonance sound signal, and output means for mixing and outputting the tone signal and the first and second resonance sound signals in accordance with performance information. Is provided. As a result, the effect is obtained that the transient sound generated at the time of playing the musical instrument is faithfully reproduced, and a musical tone rich in natural view can be easily generated. Further, according to the present invention, a drive signal is input to a closed loop including a delay to generate a tone signal, a resonance effect is given to the tone signal, and a drive signal used for generating the tone signal is generated. Also gives a resonance effect and mixes both into the musical sound signal, so for example, the phenomenon of a live piano where the impact of striking a string with a hammer propagates to the soundboard and the resonance sound is generated in response to this impact It also has the effect of being able to faithfully simulate. Further, according to the present invention, since the first and second resonance signals are generated by separate resonance means, there is an advantage that the design of the resonance means is easy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a tone synthesizer according to one embodiment of the present invention, FIG. 2 is a block diagram showing a configuration example of a resonance circuit used in the embodiment, and FIG. 3 is a resonance circuit of FIG. FIG. 3 is a block diagram illustrating a configuration example of an all-pass filter used in the embodiment. 1 ... tone control circuit, 2 ... tone generation circuit, 3 ... drive signal generation circuit, 4a, 4b ... resonance circuit, 5 ... mixed circuit.

Continuation of the front page (56) References JP-A-52-109922 (JP, A) JP-A-54-33020 (JP, A) JP-A-63-193185 (JP, A) JP-A-59-231595 (JP) JP-A-64-91193 (JP, A) JP-A-3-98094 (JP, A) JP-A-3-98097 (JP, A) JP-A-49-131112 (JP, A) Patent 2782836 (JP, A) JP, B2) JP 2828331 (JP, B2) JP-B-41-16592 (JP, B1) (58) Fields investigated (Int. Cl. ⁶ , DB name) G10H 1/00-7/12

Claims (1)

(57) [Claims] 1. A means for connecting a drive signal generating means for generating a drive signal corresponding to performance information and a delay means for delaying an input signal in a closed loop, wherein the drive signal is input to the closed loop, Tone generating means for outputting a signal circulating in the closed loop as a tone signal; first resonance means for giving a resonance effect to the tone signal and outputting a first resonance signal; A resonance means for giving a resonance effect to output a second resonance signal, and an output means for mixing and outputting the tone signal and the first and second resonance signals in accordance with performance information. A tone synthesizer comprising: