JP3097503B2 - Music synthesis apparatus and music synthesis method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical tone synthesizing apparatus and a musical tone synthesizing method for synthesizing musical tone signals, in particular, musical tone signals generated by striking and plucked instruments.

[0002]

2. Description of the Related Art Conventionally, a tone synthesizer for synthesizing a tone signal, particularly a tone signal generated by a striking or plucked musical instrument, simulates the tone of the musical instrument by using a delayed feedback algorithm to generate the tone signal. doing. The applicant of the present application has disclosed in Japanese Patent Application No. 3-243993, using such a feedback algorithm,
For example, lightly press a part of the string with a finger, release the finger immediately after picking, and emphasize the harmonics of a certain pitch, or a feedback playing method that creates a tone by creating a kind of howling (howling). A tone synthesizer for synthesizing a tone generated by the above-described method has been disclosed.

FIG. 18 shows a principle diagram for simulating a musical tone generated by a harmonic playing technique or the like.
FIG. 9 is a circuit diagram showing an algorithm of a tone synthesis process realized using the principle of FIG.

In FIG. 18, a string S is fixed to a fixed end (block) T1, and a fixed end (fret) T
2, and the position P of the string S is lightly pressed by the player's finger F. When the string S is vibrated in this state, that is, when the input vibration wave EWAVE is input, the vibration wave WLa traveling on the string S in the direction from the fixed end T1 to the finger F, and traveling on the string S in the direction from the finger F to the fixed end T2. A vibration wave WRa, a reflected wave WRb of the vibration wave WRa reflected at the fixed end T2, and a vibration wave WLb traveling from the finger F toward the fixed end T1 are generated.

The vibration wave WLa is obtained by combining the input vibration wave EWAVE and the vibration wave WLb, and the vibration wave WRa
Is a transmitted wave and a reflected wave WR of the vibration wave WLa transmitted by the finger F.
b is a composite of the reflected wave reflected by the finger F, and the vibration wave WLb is composed of the reflected wave of the vibration wave WLa reflected by the finger F and the transmitted wave of the reflected wave WRb transmitted by the finger F. It is synthesized.

FIG. 19 shows an algorithm of a tone synthesis process for generating each of the thus modeled vibration waves. This tone synthesis process is performed by using a wave guide (see Japanese Patent Application Laid-Open No. 63-40199). Has been realized.

In FIG. 1, delay units DLa and DLb are:
This simulates a delay that occurs when the vibration waves WLa and WLb propagate on the string S, respectively, and the filters FL and FR generate when the vibration waves WLb and WRa propagate on the string S, respectively. This simulates attenuation of frequency components and the like, and includes multipliers ML1 and MR1
Simulates the ratio (reflection coefficient) α (α <1) of the delayed vibration waves WLa and WRb reflected by the finger F, and the multipliers ML2 and MR2 respectively perform the delayed vibration waves WLa and WRb. This simulates the ratio 1-α at which the waves WLa and WRb are transmitted by the finger F. The multipliers ML3 and MR3 are respectively connected to the fixed end T.
1 simulates the synthesis of the traveling wave and the reflected wave at T2, and the adder AI simulates the synthesis of the input vibration wave EWAVE and the reflected wave at the fixed end T1. The devices AL and AR simulate the synthesis of the traveling wave and the reflected wave at the finger F.

That is, FIG. 19 simulates a situation in which an obstacle (finger F) prevents the vibration from propagating right and left in the string and reflection of the vibration occurs at the position of the obstacle. The amount of delay (delay) that simulates the propagation in the right and left directions corresponds to the relative position of the obstacle (the position of the finger F with respect to the distance between the fixed end T1 and the fixed end T2 in FIG. 18). The signal is divided by the ratio, the signal is extracted therefrom (using the expression of tapping the delay), and added to the delay in the opposite direction.

FIG. 20 is a diagram showing the tone synthesis process of FIG. 19 in which the junction J is replaced with an equivalent junction J '. This tone synthesis process is different from the tone synthesis process of FIG. It has been simplified.

FIG. 21 is also a simplified version of the circuit of FIG.

[0011]

However, the conventional tone synthesizer described above simulates to some extent the timbres of musical tones generated by striking and plucked musical instruments, in particular, the timbres of musical tones generated by harmonics playing, feedback playing, and the like. Although possible, the simulation quality was not yet sufficient. This is because, in actual string vibration, the distance between the string and an obstacle such as a finger fluctuates depending on the magnitude of the amplitude of the string vibration and the position of the obstacle. This is because the tone changes with a sense of modulation called "chatter".

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a tone synthesis apparatus and a tone synthesis method capable of better simulating the tone of a tone generated by a stringed or plucked instrument. With the goal.

[0013]

In order to achieve the above object, a musical sound synthesizer according to the present invention includes at least two signal delay means, and a signal loop means for circulating a musical sound signal delayed by the signal delay means; The delay means is provided between the two delay means, controls the amplitude of the traveling tone signal output from one delay means and input to the other delay means, and is output from one delay means and returns to the one delay means. In a tone synthesizer comprising a tone signal control means for controlling an amplitude of an input reflected tone signal, a control signal input means for inputting a control signal, and the input control signal and the signal loop means are circulated. Control coefficient determining means for determining a control coefficient based on the musical tone signal to be reproduced, wherein the signal control means determines whether the traveling musical tone signal And controlling the amplitude of the signal.

Preferably, the apparatus further comprises table data storage means for storing the control coefficients as table data in advance, wherein the control coefficient determination means stores the input control signal and a tone signal circulating through the signal loop means. The control coefficient is determined by selecting from the table data storage means based on the control coefficient.

A signal loop means for circulating the tone signal delayed by the signal delay means; and a signal loop means provided between the two delay means for outputting from one of the delay means and the other A first tone signal control means for controlling the amplitude of a traveling tone signal input to the delay means, and a delay means provided between the two delay means, output from one delay means and returned to the one delay means for input. A first control signal input means for inputting a first control signal, and a second control signal, wherein the first control signal input means inputs a first control signal. Control signal input means for inputting the first control signal, and a first control coefficient for determining a first control coefficient based on the input first control signal and a tone signal circulating through the signal loop means. Setting means, and second control coefficient determining means for determining a second control coefficient based on the input second control signal and a tone signal circulating through the signal loop means, and The signal control means controls the amplitude of the traveling musical tone signal in accordance with the determined first control coefficient, and the second signal control means controls the reflection in accordance with the determined second control coefficient. It is characterized in that the amplitude of the tone signal is controlled.

The tone synthesis method of the present invention includes at least two signal delay means, a signal loop means for circulating the tone signal delayed by the signal delay means, and a signal loop means provided between the two delay means. A tone for controlling the amplitude of a traveling tone signal output from the delay means and input to the other delay means, and for controlling the amplitude of a reflected tone signal output from one delay means and input back to the one delay means. A signal control means for inputting a control signal, determining a control coefficient based on the input control signal and a tone signal circulating through the signal loop means, and Means for controlling the amplitudes of the traveling musical tone signal and the reflected musical tone signal in accordance with the determined control coefficient.

[0017]

According to the structure of the present invention, a control signal is inputted,
When the control coefficient is determined based on the input control signal and the tone signal circulating in the signal loop means, the signal control means changes the amplitude of the traveling tone signal and the reflected tone signal in accordance with the determined control coefficient. Controlled.

Further, a first control signal is input, a second control signal is input, and a first control signal is input based on the input first control signal and a tone signal circulating in the signal loop means.
Is determined, and the first control coefficient is determined based on the input second control signal and the tone signal circulating through the signal loop means, the first signal control means determines the first control coefficient. The forward tone signal and the reflection tone signal are controlled in accordance with the first control coefficient, and the second signal control means controls the progress tone signal and the reflection tone signal in accordance with the determined second control coefficient. The amplitude is controlled.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

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

In FIG. 1, a musical sound synthesizer 1 according to the present embodiment is shown.
Includes a performance operator 2 for inputting performance information, a setting operator 3 for inputting various setting information, a CPU 4 for controlling the entire apparatus 1, and a control program and table data executed by the CPU 4. A memory 5 for storing or temporarily storing various input information, calculation results, and the like;
A display unit 6 for displaying various information and a signal processing device (in this embodiment, a DSP (Digital Signal Processor)) for generating a tone signal based on performance information from the performance operator 2 are used. 7) and the DSP7
And a digital-to-analog converter (DAC) 9 for converting a digital musical tone signal from the DSP 7 into an analog musical tone signal.

The above components 2 to 7 are connected to the bus 10
Are connected to each other through the DSP 7 and the DSP-RAM
The output side of the DSP 7 is connected to the input side of the DAC 9.

FIG. 2 shows the DSP 7 and DSP-R of FIG.
FIG. 3 is a block diagram for explaining an outline of a tone synthesis process performed by AM8. The tone synthesis process mainly includes an excitation waveform generator 11 that generates an excitation waveform (input waveform), and an excitation waveform generator 11 that generates the excitation waveform. Excitation waveform EWAVE
To change the pitch by delaying, or by filtering to change the timbre.

The excitation waveform generator 11 is supplied with a key-on signal KON and a touch signal TOUCH such as an after touch in response to the operation of the performance operator 2, and generates a tone set by the setting operator 3. A signal WAVEFORM indicating the shape of the corresponding excitation waveform and other signals are supplied, and the excitation waveform generator 11 generates an excitation waveform EWAVE based on the supplied signals and outputs the waveform to the delay loop unit 12.

The delay loop section 12 is supplied with a signal PITCH for determining the delay amount in accordance with the pitch (pitch) specified by the operation of the performance operation element 2, and the timbre set by the setting operation element 3. Is supplied, a signal FILTCOEF indicating a filter coefficient determined according to the position data, position data PD determined according to the position of the finger pressing the string, and other signals are supplied. The delay loop unit 12 includes the DSP-R
From the position (address) where the excitation waveform EWAVE was written in the AM8, the excitation waveform EWAVE written at an address separated by the address determined by the signal PITCH is read, and the filtering processing according to the signal FILTCEF and the position data PD described later are performed. Then, a tone signal OUT is generated by performing such processing as described above, and is output to the DAC 9.

The excitation waveform generating section 11 uses a waveform memory reading method, a modulation method such as FM and AM, a method of generating a tone signal by a pulse generator or a noise generator, and various sensor signals such as a striking sensor. The tone signal may be generated using any method such as a method of generating a tone signal.

The present invention mainly relates to the delay loop unit 1.
2, only the configuration of the delay loop unit 12 is illustrated and described below unless otherwise specified.

FIGS. 3A and 3B are diagrams for explaining the operation principle of the musical sound synthesizer 1 of the present embodiment. FIG.
(B) shows a case where the string F is lightly pressed with the finger F, and (c) shows a case where the finger F is not brought into contact with the string S.

As shown in FIG.
19, the magnitude of the reflection coefficient α described with reference to FIG. That is, the present invention changes the ratio of the reflected wave propagating through the waveguide in accordance with the strength of the finger F in contact with the string S with respect to the conventional musical sound synthesizer, thereby changing the tone color of the musical sound. The difference is that they are changed.

FIG. 4 is a circuit diagram showing a detailed configuration of the delay loop unit 12, which is a modification of the circuit of FIG. Therefore, in FIG. 4, the components corresponding to those in FIG. 20 are denoted by the same reference numerals, and description thereof will be omitted.

As described above, in this embodiment, since the delay loop unit 12 is constituted by the DSP 7 and the DSP-RAM 8, the delay loop unit 12 is realized by a microprogram of the DSP 7. That is, the delay loop unit 12 is not actually configured in hardware by a circuit as shown in FIG. 4, but is only described in hardware for convenience of explanation. Of course, it is also possible to configure the delay loop unit 12 with hardware as shown in FIG. 4 without using the DSP 7 and the DSP-RAM 8, and to configure the delay loop unit 12 with only the CPU 4 and the memory 5. Alternatively, it is also possible to configure purely software only. Hereinafter, unless otherwise specified, the circuit diagram is assumed to be a visual representation of a processing algorithm performed by a microprogram of the DSP 7.

In FIG. 4, the output of the adder AM is supplied to an integrator I, and the integrated output from the integrator I is supplied to an adder A1.
Is supplied to one input side. Position data PD indicating the position of the obstacle is inverted and supplied to the other input side of the adder A1. Here, when the finger F is taken as an obstacle, the position data PD represents the strength with which the finger F presses the string S. The position data PD includes performance operators such as a keyboard and various performance auxiliary operators represented by pedals and wheels (operators in the performance operator 2).
May be given in accordance with the operation amount corresponding to the operation, or a time-varying signal may be generated and given by an envelope generator (EG) or the like.

The output of the adder A1 is supplied to a reflection coefficient table T for determining the reflection coefficient α according to the output. In the figure, the output of the adder A1 is described to be directly supplied to the reflection coefficient table T. This is because the reflection coefficient table T is searched according to the output from the adder A1 to determine the reflection coefficient α. It is needless to say that it is determined that the determined reflection coefficient α is output from the reflection coefficient table T.

The reflection coefficient α determined and output in this way is inverted and supplied to one input side of the adder A2. “1” is supplied to the other input side of the adder A2, and the adder A2 multiplies “1-α (transmission amount)” by the multiplier VM.
1, VM2.

As described above, the distribution of the delay amounts DR and DL of the delay units DRa and DLa is performed based on the positional relationship on the chord length of the chord S where the obstacle contacts. For example, the string S
When an obstacle is placed at the center position of, the delay amount DR:
DL is 1: 1. Of course, the total delay (DR + D
L) corresponds to the entire length of the string S and the pitch of the musical tone to be generated.

The tone output may be obtained by extracting a signal circulating in the delay loop section 12 from an arbitrary position. Alternatively, the output may be taken out from a plurality of locations and arbitrarily combined or mixed.

Each part delay (delay devices DLa, DLb,
DRa, DRb) are configured by using a shift register or a RAM in the case of digital processing.
(All Pass Filter) or JP-A-2-281297
The technique disclosed in Japanese Patent Application Laid-Open Publication No. H10 (FIR type delay interpolation) may be applied.

Further, a filter in the loop (filter F
L, FR) are LPF (Low pass Filter), HPF (Hig
hpass Filter) or APF, and may be used in combination. For example, if an APF is inserted in the loop so that the delay amount of the loop has a frequency characteristic, it is possible to control the harmonics of the generated musical tone so as to deviate from the integer order relationship. This reproduces a phenomenon in which the frequency relationship of the harmonics deviates from the integer order relationship due to the effect of the actual string stiffness, and the effect of the present invention is further emphasized. In particular, it is suitable for synthesizing musical instrument sounds using a highly rigid string such as a bass (fretless bass). The structure of the filter is FIR and II
Any of R may be used as appropriate.

FIGS. 5A and 5B are circuit diagrams showing a specific configuration of the integrator I. FIG. 5A shows a configuration in which a delay D is provided immediately after an adder, and FIG. On the return path. The integrator I is not limited to this, and for example, a coefficient multiplier may be provided on the input, output or feedback path.

In this embodiment, the output from the adder AM is integrated by the integrator I, and the integrated value is supplied to the adder A1. This is based on the assumption that the signal circulating in the delay loop unit 12 is a displacement speed signal of the vibration wave, so that this displacement speed is converted into a displacement, and the position data PD to be added by the adder A1.
This is because it is necessary to match the dimensions. Of course, the signal in the delay loop unit 12 may be regarded as “displacement”, and this “displacement” may be adopted. In this embodiment, the displacement speed is adopted. Therefore, the output from the adder AM is added using the integrator I, that is, the displacement is obtained from the displacement speed, and the displacement is supplied to the adder A1. Note that a filter such as an LPF may be used in place of the integrator I. As described above, when a signal during delay is regarded as a displacement, the integrator I is not used and the adder AM is used.
May be supplied to the adder A1 as it is.

FIG. 6 is a diagram showing an example of the characteristics of the reflection coefficient table T. In FIG. 6, the vertical axis indicates the reflection coefficient α,
The horizontal axis indicates the position data PD. In the present embodiment, the reflection coefficient table T takes "0" in the non-contact area Ta, and takes real values from 0 to 1 in the contact area Tb. For example, as shown in FIG.
Is defined, the smaller the parameter a, the narrower the boundary area between contact and non-contact, and abrupt timbre change occurs. This parameter a represents the hardness (in other words, softness) of the contacting object. The smaller the value of the parameter a, the harder the object is in contact. The parameter h indicates the rate of reflection of how much vibration is reflected when the string S completely contacts the obstacle, and the upper limit is usually “1”. This parameter h expresses the strength of the influence of the obstacle on the string vibration, and is mainly related to the relative mass of the obstacle to the string S. When the obstacle is heavy or the string S
When the distance is thin, the influence of the obstacle on the string vibration is strong, and the value of the parameter h becomes large.

Note that h / a may be employed as a parameter instead of the parameter a. In this case, the larger the value h / a, that is, the steeper the inclination of the straight line, the harder the contacting object.

The control processing executed by the tone synthesizer 1 configured as described above, in particular, by the delay loop unit 12, will be described below with reference to FIG.

FIGS. 7A and 7B are timing charts showing control timings when the musical sound generated by the harmonic synthesizing technique and the mute playing technique are simulated by the musical tone synthesizing apparatus 1. FIG. 7A shows the output timing of the key-on signal. (b) shows the output timing of the position data PD at the time of harmonic playing, and (c) shows the output timing of the position data PD at the time of mute playing. In the figure, the vertical axis indicates the value of each signal, and the horizontal axis indicates time.

For example, to simulate a musical tone by harmonics playing, a key-on signal is output ("1").
At the same time, the position data PD is supplied to the adder A1 while decreasing from the maximum value (the value indicated by the parameter h) to “0” at the slope h / a.

The adder A1 adds the position data PD supplied in this way and the displacement (output from the integrator I) generated by the vibration of the string S, and adds the position data PD in the direction perpendicular to the string S of the obstacle. Output to the reflection coefficient table T as position data. From this position data, it is determined whether the obstacle and the string S are in non-contact (position data ≦ 0) or in contact (position data> 0), that is, reflection is performed according to the value of the position data. The coefficient table T is searched, and if there is contact, the positive reflection coefficient value α is output to the adder A2, and if not, “0” is output to the adder A2.

On the other hand, when simulating a musical tone by the mute playing method, the key-on signal is stopped ("0"), and after a predetermined time t, the position data PD is increased from "0" to the maximum value with a slope h / a. And supplies it to adder A1. Subsequent processing is the same as the above-described simulation of the musical tone by the harmonic playing technique, and therefore, the description thereof is omitted.

In this embodiment, the reflection coefficient table T
Was used to determine the reflection coefficient α, but this is not limiting.
For example, the reflection coefficient α may be obtained by another method such as conditional branching.

As described above, in this embodiment, the displacement amount of the string S and the position data P of the obstacle output from the integrator I
D is calculated, and the reflection coefficient table T is calculated from the difference.
, And a tone signal is generated by using the obtained reflection coefficient α, so that a stringed and plucked instrument such as a harmonics playing method or a mute playing method is generated. The tone can be simulated better.

In this embodiment, 1 is output from the adder AM.
Although the contact / non-contact control is performed using one output, the contact / non-contact control may be performed using signals extracted from a plurality of locations without being limited to this.

Actually, the delay loop unit 1 shown in FIG.
In order to realize No. 2, since this circuit is configured to take out a signal from the junction output of the waveguide and return it to the junction, for example, in FIG. 4, the case where the integrator I is omitted or FIG. In the case of adopting the configuration of ()), a delay-free loop may be generated. When such a delay-free loop occurs, a portion where signal processing cannot be performed by the microprogram occurs, so that one delay must be inserted somewhere in this loop.

FIG. 8 is a circuit diagram showing a modified example in which the delay loop unit 12 of FIG. 4 is modified in order to solve this problem. The only difference is that a delay device D1 is inserted on the output side of the device A2. The other configuration is the same as the configuration in FIG.

Although the occurrence of a delay-free loop can be prevented in this way, even if one delay is inserted, this loop tends to cause problems such as ringing. In order to cope with this ringing problem, a first-order FI having a coefficient of 0.5 and a so-called averager of 0.5 shown in FIG.
An R (Finite Impulse Respons) filter may be appropriately inserted.

In order to prevent the occurrence of a delay-free loop, it is conceivable to prevent the occurrence of a loop.

FIG. 10 shows an example in which a loop is not generated by modifying the circuit of FIG. 4. In this modified example, an adder A3 is added to the circuit of FIG. The difference is that the outputs from the delay units DLa and DRb are added by the adder A3 and the addition result is supplied to the integrator I. As a result, a loop does not occur, and the occurrence of a delay-free loop can be prevented.

FIG. 11 shows a circuit obtained by replacing the circuit of FIG. 4 with an equivalent circuit.
1 in that a multiplier M1 is used instead of VM2. This circuit is very similar to a non-linear feedback algorithm for simulating reed instruments and the like. Therefore, by replacing the reflection coefficient table T with a table corresponding to the non-linear feedback algorithm, the tone synthesis simulation for reed instruments and the like can be performed. Programs can be shared.

FIG. 12 is a circuit diagram of a delay loop unit in which the present invention is applied to the conventional circuit of FIG.

As described above, the circuit shown in FIG. 21 is a simplified version of the circuit shown in FIG. 19, and the circuit shown in FIG. 4 is obtained by applying the present invention to the circuit shown in FIG. 4 can be said to be a simplified version of the circuit of FIG. The operation of the present circuit is the same as the operation of the circuit of FIG. 4, and a description thereof will be omitted.

If the multiplier ML is not required, or if it is multiplied by a coefficient G for determining the loop gain, the value of G can control the attenuation characteristics of the generated musical sound.

In addition, as the signal which is inverted and input to the adder A4, the signal indicated by,, in the figure may be used (that is, any signal that goes around a loop may be used), or a plurality of signals may be used. Signals from locations may be combined and used as appropriate.

FIG. 13 is a circuit diagram showing the configuration of the delay loop unit of the tone synthesizer according to the second embodiment of the present invention.

The delay loop of this embodiment is different from the first embodiment in that a tone is synthesized in consideration of a case where an obstacle has a thickness. That is, in the first embodiment, the simulation was performed assuming that all the string vibrations blocked by the obstacle are reflected. However, when the obstacle has a thickness, the string vibration is not completely reflected, We must also consider damping.

In FIG. 13, the reflection coefficient α signal output from the reflection coefficient table T is branched into two, one of which is an adder A.
2 and the other one is supplied to a multiplier M2
Is supplied to the input side. An obstacle thickness signal TD is supplied to an input side of the multiplier M2 to which a multiplication coefficient is input, and the multiplier M2 performs an operation of “reflection coefficient α × obstacle thickness signal TD”, and The multiplication coefficient of MR1 is supplied to the input side. This simulates a state where a part of the reflected wave is attenuated by the obstacle. That is, in the first embodiment, the transmission coefficient is 1-α with respect to the reflection coefficient α.
The simulation was performed assuming that the sum of the reflected wave and the traveling wave (transmitted wave) is “1”. However, when the obstacle has a thickness, when the reflection loss coefficient β is introduced,
The reflection ratio of the vibration is αβ, and the transmission ratio is 1−α. The reflection loss coefficient β takes the maximum value “1” when the obstacle has no thickness, and approaches 0 as the thickness increases. Further, the value of the reflection loss coefficient β differs depending on the material of the obstacle.

The circuit shown in FIG. 13 is not constructed based on the circuit shown in FIG. 4 (junction J 'has an X-shape), but is based on the circuit shown in FIG. Was configured. This is because the sum of the ratio of reflection and the ratio of transmission is not “1”, so that the configuration based on the circuit of FIG. 4 is rather complicated. However, the configuration may be based on the circuit of FIG. .

As described above, this embodiment simulates the musical tone generated when the obstacle has a thickness and the string vibration is attenuated by the thickness. Can be synthesized.

FIG. 14 is a circuit diagram showing a simplified example of the circuit shown in FIG. 13, in which the reflection loss is considered in the simplified example shown in FIG.

FIG. 15 is a block diagram showing the configuration of the delay loop unit of the tone synthesizer according to the third embodiment of the present invention.

The delay loop of this embodiment is different from the second embodiment (FIG. 13) only in how the position data PD is provided. That is, in the present embodiment, by providing the position data PD as shown in FIG. 15, not only the phenomenon called "chatter" synthesized in the first and second embodiments but also the string S or the hammer is played. (Not shown) to generate a musical sound when hit. At this time, the position data PD may be changed by an EG, a waveform generator, or the like so that the picking finger F or the hammer striking the string is moved. The fluctuation signal to cause this fluctuation is
The excitation waveform EWAVE may be used, or another signal may be used. Further, the shape and amplitude of the fluctuating waveform may be variably controlled in accordance with the performance operation.

However, considering the simulation of string striking or the like strictly, the excitation waveform is also generated by the interaction between the string and the hammer, so that the circuit of the present embodiment is not accurate enough.
Since the degree of freedom for changing the timbre is expanded by arbitrarily giving the distance between the initial waveform and the obstacle independently and arbitrarily, it can be interpreted as an advantage of the present invention.

FIG. 16 is a circuit diagram showing a modification of the circuit of FIG. 15. This modification is different from the circuit of FIG. 15 in that an excitation waveform EWAVE is generated by itself. . That is, a differentiator DI (the configuration of which is shown in FIG. 17) is inserted on the output side of the reflection coefficient table T, and the output of the differentiator DI is returned to the adders AL and AR.
An excitation waveform EXWV is generated.

As described above, in this modification, the waveform generator for generating the excitation waveform is a simple differentiator D as shown in FIG.
Since it can be replaced with I, the manufacturing cost of the device can be reduced.

It goes without saying that the configuration of the differentiator DI need not be limited to that shown in FIG.

[0073]

As described above, according to the present invention,
When the control signal is input and the control coefficient is determined based on the input control signal and the tone signal circulating through the signal loop means, the signal control means causes the traveling tone signal and the forward tone signal to be determined in accordance with the determined control coefficient. Since the amplitude of the reflected musical tone signal is controlled, it is possible to more effectively simulate peculiar timbres generated by a stringed or plucked instrument such as a harmonics playing technique or a mute playing technique.

Further, a first control signal is input, a second control signal is input, and a first control signal is input based on the input first control signal and a tone signal circulating through the signal loop means.
Is determined, and the first control coefficient is determined based on the input second control signal and the tone signal circulating through the signal loop means, the first signal control means determines the first control coefficient. The forward tone signal and the reflection tone signal are controlled in accordance with the first control coefficient, and the second signal control means controls the progress tone signal and the reflection tone signal in accordance with the determined second control coefficient. Since the amplitude is controlled, it is possible to synthesize a musical tone closer to the sound of a string.

[Brief description of the drawings]

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

FIG. 2 is a block diagram for explaining an outline of a tone synthesis process performed by the DSP and the DSP-RAM of FIG. 1;

FIG. 3 is a diagram for explaining the operation principle of the musical sound synthesizer of the first embodiment.

FIG. 4 is a circuit diagram illustrating a detailed configuration of a delay loop unit according to the first embodiment.

FIG. 5 is a circuit diagram showing a specific configuration of the integrator of FIG. 4;

FIG. 6 is a diagram illustrating an example of characteristics of the reflection coefficient table of FIG. 4;

FIG. 7 is a timing chart showing control timing when simulating a musical tone generated by a harmonics playing technique and a mute playing technique in the tone synthesizer of the first embodiment.

FIG. 8 is a circuit diagram showing a modified example in which the delay loop unit of FIG. 4 is modified.

FIG. 9 is a circuit diagram illustrating a configuration of an example of an averager.

FIG. 10 is a diagram showing an example in which a loop is not generated by modifying the circuit of FIG. 4;

FIG. 11 is a circuit diagram in which the circuit of FIG. 4 is replaced with an equivalent circuit.

FIG. 12 is a circuit diagram of a delay loop unit in which the present invention is applied to the conventional example of FIG. 21;

FIG. 13 is a circuit diagram showing a configuration of a delay loop unit of a tone synthesizer according to a second embodiment of the present invention.

FIG. 14 is a circuit diagram illustrating a simplified example of the circuit of FIG. 13;

FIG. 15 is a circuit diagram showing a configuration of a delay loop unit of a musical sound synthesizer according to a third embodiment of the present invention.

FIG. 16 is a circuit diagram showing a modification example in which the circuit of FIG. 15 is modified.

FIG. 17 is a circuit diagram showing a configuration of an example of a differentiator shown in FIG. 16;

FIG. 18 is a diagram showing a principle diagram for simulating a musical tone generated by a harmonics playing technique or the like.

FIG. 19 is a circuit diagram showing an algorithm of a tone synthesis process realized using the principle of FIG. 18;

20 is a circuit diagram in which a junction J in the tone synthesis processing of FIG. 19 is replaced with an equivalent junction J '.

FIG. 21 is a simplified circuit diagram of the circuit of FIG. 19;

[Explanation of symbols]

4 CPU (control coefficient determining means, first control coefficient determining means) 12 delay loop section (signal loop means) A1 adder (control signal input means, first control signal input means) AL, AR adder (music signal Control means, first tone signal control means) DLa, DLb, DRa, DRb delay units (signal delay means) VM1, VM2 multipliers (tone signal control means, first tone signal control means) T reflection coefficient table (table Data storage means) ML1, MR1 multiplier (second tone signal control means) M2 multiplier (second control signal input means, second control coefficient determination means)

Claims (4)

(57) [Claims] 1. At least two signal delay means,
Signal loop means for circulating the tone signal delayed by the signal delay means; and a signal loop means provided between the two delay means;
Controlling the amplitude of the traveling tone signal output from one delay means and input to the other delay means, and controlling the amplitude of the reflected tone signal output from one delay means and input back to the one delay means A control signal input means for inputting a control signal, and a control coefficient determined based on the input control signal and a tone signal circulating through the signal loop means. And a control coefficient determining unit for controlling the amplitude of the traveling musical tone signal and the reflected musical tone signal in accordance with the determined control coefficient. 2. The apparatus according to claim 1, further comprising: table data storage means for storing the control coefficients as table data in advance, wherein the control coefficient determination means is configured to perform the control based on the input control signal and a tone signal circulating through the signal loop means. 2. The musical tone synthesizer according to claim 1, wherein the control coefficient is determined by selecting from the table data storage means. 3. At least two signal delay means,
Signal loop means for circulating the tone signal delayed by the signal delay means; and a signal loop means provided between the two delay means;
A first tone signal control means for controlling the amplitude of a traveling tone signal output from one delay means and input to the other delay means; and a first tone signal control means provided between the two delay means and output from one delay means. A second tone signal control means for controlling the amplitude of the reflected tone signal inputted back to the one delay means; and a first control signal input for inputting a first control signal. Means, second control signal input means for inputting a second control signal, and a first control coefficient based on the input first control signal and a tone signal circulating through the signal loop means. First control coefficient determining means for determining, and second control coefficient determining means for determining a second control coefficient based on the input second control signal and a tone signal circulating through the signal loop means. Having, said The first signal control means controls the amplitude of the traveling musical tone signal in accordance with the determined first control coefficient, and the second signal control means controls the amplitude in accordance with the determined second control coefficient. A tone synthesizer for controlling the amplitude of the reflected tone signal. 4. Includes at least two signal delay means,
Signal loop means for circulating the tone signal delayed by the signal delay means; and a signal loop means provided between the two delay means;
Controlling the amplitude of the traveling tone signal output from one delay means and input to the other delay means, and controlling the amplitude of the reflected tone signal output from one delay means and input back to the one delay means A tone signal synthesizing method, comprising: inputting a control signal; determining a control coefficient based on the input control signal and a tone signal circulating through the signal loop means; A tone synthesizing method, wherein the signal control means controls the amplitudes of the traveling tone signal and the reflected tone signal according to the determined control coefficient.