JP3090667B2 - Music synthesizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

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 various musical sound waveforms by calculation or modulating 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 sounds by operating an electric model that simulates 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, a device in which a delay circuit simulating a propagation delay of vibration in a string and a low-pass filter simulating an acoustic loss in the string are connected in a closed loop is well known. I have. 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"). , This musical sound is called a direct sound for the sake of convenience). 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, JP-A-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, the above-described conventional musical sound synthesizer can reproduce the direct sound and the resonance to the direct sound, but cannot reproduce the transient sound based on the impact at the time of the performance. There is a problem that natural instrument sounds cannot be generated. 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, transient sounds
When sound is reproduced by a sound source based on a recording / reproducing method such as PCM, sound quality is greatly affected by a recording technique, and in some cases, 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 provides a musical tone forming means for forming a musical tone signal corresponding to performance information, a driving signal generating means for generating a driving signal different from the musical tone signal corresponding to performance information, A mixing unit that mixes and outputs the tone signal and the drive signal at a ratio according to performance information, and a resonance unit that receives a signal output from the mixing unit and generates a resonance signal for the signal, The mixing ratio of the drive signal and the tone signal in the mixing means is controlled according to the pitch of the tone to be generated. [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. A tone signal corresponding to the performance information is generated by the tone forming means. The mixing means mixes the tone signal and the drive signal different from the tone signal at a ratio according to the performance information and outputs the result. At this time, the mixing ratio of the drive signal and the tone signal in the mixing means is controlled according to the pitch of the tone to be generated. The resonance means generates a resonance signal corresponding to the signal output from the mixing means. "Example" Hereinafter, an example of the present invention will be described with reference to the drawings, along with a description of a reference example serving as background art of the present invention.

[Reference example]

FIG. 1 is a block diagram showing a configuration of a musical tone synthesizer for piano sounds according to a reference example 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. Closed loop circuit and drive signal generation circuit for supplying a drive signal to the closed loop circuit
2d. The drive signal generation circuit 2d has a waveform ROM (read only memory). The waveform ROM stores a signal waveform containing many frequency components such as an impulse waveform on a PC.
An M-coded time-series digital signal is stored.
When a tone is generated, a key-on signal is sent from the tone control circuit 1.
When KEYON is supplied, digital signals are sequentially read from the waveform ROM and supplied to the adder 2a as the above-described drive signal. Then, this drive signal circulates through a closed loop consisting of the adder 2a → the delay circuit 2b → the filter 2c. This closed loop operates as a resonance circuit having a primary resonance frequency corresponding to the reciprocal of a delay time required for a signal to make a round of the closed loop, and a higher resonance frequency that is an integral multiple of the primary resonance frequency. When the drive signal circulates through the closed loop, the resonance frequency components in the drive signal are emphasized. 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, the filter 2c is usually
This is realized by a low-pass filter. Here, since the strings stretched over the piano have different frequency characteristics of the attenuation rate of the vibration, the tone control circuit 1 gives the filter 2c a tone color parameter TN corresponding to the string. , The filter calculation coefficient in the filter 2c can be switched. In this manner, the direct tone signal SDRY of the pitch and tone specified by the tone control circuit 1 is generated. Note that, in addition to the above-described configuration, the tone generation circuit 2 may be configured by, for example, an FM sound source or a PCM sound source. The drive signal generation circuit 3 has the same configuration as the drive signal generation circuit 2a described above.
When YON is supplied, a digital signal corresponding to a signal waveform (for example, an impulse) corresponding to an impact when a piano string is hit with a hammer is generated as an impact signal IP. This shock signal IP is input to the resonance circuit 4. The resonance circuit 4 simulates the acoustic characteristics of a sound board of a piano, and is realized by, for example, a closed loop circuit including a delay circuit and a filter as used in the above-described tone generation circuit 2. Generally, a sound board of a piano has many resonance frequencies. According to this, a plurality of closed loop circuits having different resonance frequencies are connected in parallel to realize a resonance circuit 4 that faithfully reproduces the acoustic characteristics of the sound board of the piano. be able to. With this resonance circuit 4,
A resonance effect is given to the shock signal IP output from the drive signal generation circuit 3. As a result, the impact given to the strings from the hammer propagates to the soundboard, and a transient sound signal STRN corresponding to the transient sound generated by the resonance of the soundboard is output. A configuration example of the resonance circuit 4 will be described later. The mixing circuit 5 includes multipliers 5a and 5b and an adder 5c. The multiplier 5a is supplied with the transient sound signal STRN described above, the multiplication coefficient gamma ₁ supplied from the tone control circuit 1 is multiplied. Further, the multiplier 5b includes the direct sound signal SD described above.
RY is inputted, the multiplication coefficient gamma ₂ supplied from the tone control circuit 1 is multiplied. Then, each multiplication result is added by the adder 5c, and the addition result is 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 circuits 3 and 2d are driven, and the transient sound signal STRN and the direct sound signal SDRY are generated as described above. Prior to the above operation, the tone control circuit 1 outputs the multiplication coefficients γ ₁ and γ ₂ , and sets the mixing ratio of the transient sound signal STRN and the direct sound signal SDRY in the mixing circuit 5.
In general, in the case of a piano, the higher the pitch, the more the transient sound is emphasized. Therefore, as the pitch increases, the multiplication coefficient γ ₁ is set to be larger than the multiplication coefficient γ ₂ as the pitch increases. . In this way, a musical tone rich in natural sensation is generated in which the transient sound when the string is struck by the hammer and the direct sound due to the vibration of the string are 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 realism can be obtained. Note that the tone generation beginning, the multiplication coefficient gamma ₁ to a large value, to emphasize the transient sound by setting the multiplication coefficient gamma ₂ to a small value, the smaller value the multiplication coefficient gamma ₁ over time, the multiplication coefficient gamma ₂ May be smoothly changed to a large value so that the direct sound based on the vibration of the string is gradually emphasized. By doing so, a musical sound with a more natural feeling is generated.

【Example】

FIG. 2 is a block diagram showing a configuration of a musical tone synthesizer for piano sounds according to an embodiment of the present invention. Note that, in the figure, parts corresponding to those in FIG. 1 described above are denoted by the same reference numerals. In this embodiment, the shock signal IP output from the drive signal generation circuit 3 and the direct sound signal SD output from the tone generation circuit 2
A different point from the first embodiment is that a mixing circuit 6 for mixing RY is provided and an output of the mixing circuit 6 is input to the resonance circuit 4. Here, the tone control circuit 1a is included in the mixing circuit 6.
Supply the multiplication coefficients γ ₃ and γ ₄ to control the mixing ratio of the impact sound signal IP and the direct sound SDRY. Specifically, similar to the above reference example, as the pitch becomes higher, the larger value the multiplication coefficient gamma _3, multiplication coefficient gamma ₄ is set to a small value, so that the ratio of the impact sound signal IP becomes larger Controlled. According to this tone synthesizer, a signal corresponding to a resonance sound obtained by transmitting both a shock when a string is struck by a hammer and a vibration excited in the string to the soundboard is output from the resonance circuit 4. The output signal of the resonance circuit 4 and the direct sound signal SDRY are mixed by the mixing circuit 6 and output. Therefore, it is possible to generate a musical tone in which a direct sound, a resonance sound to the direct sound, and a transient sound, which are generated in an actual natural musical instrument, are mixed in a well-balanced manner.

[Configuration example of resonance circuit]

FIG. 3 shows the resonance circuit 4 in the reference example and the embodiment.
FIG. 3 is a block diagram illustrating a configuration example of FIG. However, the resonance circuit of FIG. 3 has a configuration in which an output L for the left channel and an output R for the right channel are provided in consideration of correspondence to stereo reproduction. Therefore, when this resonance circuit is applied to the above reference example and embodiment, a mixing circuit for mixing with the direct sound signal corresponding to each of the left channel output L and the right channel output R is provided, or Use either left or right channel output. As shown in FIG. 3, the resonance circuit includes multipliers 61 to 64 for multiplying an input signal by a predetermined coefficient, and a closed loop circuit 71.
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
Have different resonance characteristics. By connecting these closed loop circuits 71 to 74 in parallel, a resonance circuit having resonance characteristics corresponding to the sum of the resonance characteristics of the closed loop circuits 71 to 74 is realized. 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. Therefore, in the closed loop circuit 71, a resonance characteristic of an inharmonic overtone structure in which the higher-order resonance frequency does not become 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 non-harmonic resonance frequency components is selected from the input signals, and is gradually attenuated by the low-pass filter 174 while passing through the closed loop. Circulate. The resonance characteristics of a closed loop circuit using such an all-pass filter are disclosed in, for example, Japanese Patent Publication No. 56-28274. The signal circulating in the closed loop circuit 71 is a 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. Incidentally, as the all-pass filters 173, 91 and 92, those having conventionally known configurations shown in FIGS. 4 (a) to 4 (d) can be used. According to this resonance circuit, each of the closed loop circuits 71 to 74
In addition to the fact that the following resonance frequencies are different from each other, since the respective resonance characteristics are non-harmonic, resonance characteristics including an extremely large number of resonance frequencies corresponding to 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. By applying this resonance circuit to the above-described reference example and embodiment, it is possible to further synthesize a tone similar to a tone generated from an actual piano. 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 tone generating means for forming a tone signal corresponding to performance information, and a drive signal for generating a drive signal different from the tone signal corresponding to performance information Generating means, and mixing means for mixing and outputting the tone signal and the drive signal at a ratio according to performance information,
And a resonance means for receiving a signal output from the mixing means and generating a resonance signal for the signal, and mixing the tone signal and the drive signal and then inputting the signal to the resonance means. It is possible to obtain a resonance sound obtained by transmitting both the impact when the string is struck and the vibration excited by the string to the soundboard. Further, a mixing result obtained by mixing the tone signal and the drive signal at a ratio according to the performance information by the mixing means is input to the resonance means,
In addition, since the mixing ratio of the drive signal and the tone signal in the mixing means is controlled in accordance with the pitch of the tone to be generated, for example, in a natural musical instrument, resonance with an impact when a string is struck by a hammer is performed. It is possible to faithfully simulate such a phenomenon that the ratio of the resonance to the vibration excited by the sound and the string differs depending on the pitch. Therefore, it is possible to easily generate a natural sound including a transient sound generated when a musical instrument is played.

[Brief description of the drawings]

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

Claims (2)

(57) [Claims] 1. A tone generator for forming a tone signal corresponding to performance information; a drive signal generator for generating a drive signal different from the tone signal corresponding to performance information; A mixing means for mixing and outputting at a ratio according to the performance information; and a resonance means for inputting a signal output from the mixing means and generating a resonance signal for the signal, and a driving signal in the mixing means. A tone synthesizer characterized in that a mixing ratio with a tone signal is controlled in accordance with a pitch of a tone to be generated. 2. The apparatus according to claim 1, further comprising second mixing means for mixing and outputting a tone signal output from said tone generating means and a resonance signal output from said resonance means. A musical sound synthesizer as described.