JPH01269995A - Signal interpolator for musical sound signal generating device - Google Patents

Abstract

PURPOSE:To vary timbre smoothly as to an auditory feeling by separating 1st and 2nd waveform signals into waveform signals which have different frequency characteristics and increasing or decreasing the mixing rates of those waveform signals with different variation characteristics according to the variation of a musical sound control element. CONSTITUTION:The 1st and 2nd waveform signals which are outputted by waveform signal generating means 13 and 14 at expected pitch frequencies of sounding and have different waveforms are outputted while separated into waveform signals having different frequency characteristics through filters 15-18, 21, and 22, the mixing rates of waveforms signals which are separated from the 1st waveform signal and outputted are decreased gradually with different variation characteristics, and the mixing rates of the waveform signals which are separated from the 2nd waveform signal and outputted are increased gradually with different variation characteristics. Consequently, the auditory separation between the timbre regarding the 1st waveform signal and the timbre regarding the 2nd waveform signal becomes small and auditory smooth variation is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a musical tone generator having a waveform signal generating means that generates first and second waveform signals having different waveforms at the pitch frequencies of musical tones to be generated. It relates to a signal interpolator applied to a signal generation device, and in particular, the first waveform signal and the second waveform signal are calculated based on the elapsed pronunciation time, the strength of the key touch, the pitch of the pronunciation, and the operation of the timbre control operator. A musical tone signal generating device that outputs a waveform signal that smoothly changes from the first waveform signal to the second waveform signal according to a change in the musical tone control element by interpolating according to a musical tone control element such as a volume. Concerning signal interpolators for.

(Prior art) Conventionally, this type of interpolator has been proposed, for example, in
As disclosed in Publication No. 8, a mixing means for mixing first and second waveform signals having different waveforms output from a waveform signal generating means, and a mixing ratio of the first and second waveform signals in the mixing means. a mixing ratio control means for controlling the first waveform signal to gradually decrease and the second waveform signal to gradually increase as time elapses from the start of sound generation, A waveform signal that smoothly changes to a waveform signal is output.

(Problem to be Solved by the Invention) However, in the conventional device described above, during the change from the first waveform signal to the second waveform signal, the first waveform signal and the second waveform signal
Since the two waveform signals are simply mixed together, the listener hears the musical tone of the timbre related to the first waveform signal and the musical tone of the timbre related to the second waveform signal separately, and the timbre is audibly different. It doesn't feel like the changes are being made smoothly.

The present invention was devised in view of the above-mentioned auditory problems, and its purpose is to change the timbre from the first waveform signal to the second waveform signal so that the timbre changes smoothly in the auditory sense. It is an object of the present invention to provide a signal interpolator for a musical tone signal generating device that gives a sense of sensation.

(Means for Solving the Problems) In order to achieve the above object, the structural features of the present invention are as follows:
A first waveform signal and a second waveform signal having different waveforms, which are outputted from the waveform signal generating means at the pitch frequency to be produced, are determined based on the elapsed time of sound generation, the strength of the key touch, the pitch of the sound, and the tone control operator. A signal interpolator for a musical tone signal generation device that performs interpolation according to a musical tone control element such as a manipulated variable is configured to separate the first waveform signal into a plurality of waveform signals having different frequency characteristics and output the same; a filter means for separating the waveform signal into a plurality of waveform signals having different frequency characteristics and outputting the separated waveform signals, a mixing means for mixing the plurality of waveform signals respectively separated and outputted from the first and second waveform signals, and the musical tone. In response to a change in a control element, each mixing ratio of a plurality of waveform signals separated and outputted from the first waveform signal in the mixing means is controlled to gradually decrease with different change characteristics, and the second waveform signal and a mixing ratio control means for gradually increasing each mixing ratio of a plurality of waveform signals separated and outputted from the mixing means in the mixing means, respectively, with different change characteristics.

(Operation of the Invention) In the present invention configured as described above, the filter means separates the first and second waveform signals into a plurality of waveform signals having different frequency characteristics, and the mixing rate control means changes the musical tone control element. reducing each mixing ratio of the plurality of waveform signals separated from the first waveform signal according to different change characteristics;
Since the mixing ratio of each of the plurality of waveform signals separated from the second waveform signal is increased with different change characteristics, the waveform signals mixed by the mixing means and outputted from the same means are mixed from the first waveform signal to the second waveform signal. The waveform signal is gradually changed to
During this change, the various frequency components constituting the first and second waveform signals gradually change at different rates of change.

(Effects of the Invention) As a result of the above-described operation, according to the present invention, when changing from the first waveform signal to the second waveform signal, it has the characteristics of the first and second waveform signals and has a subtle difference. Waveform signals with different frequency components are mixed according to changes in musical tone control elements, and the first waveform signal and the second waveform signal are not simply mixed, so the timbre related to the first waveform signal The auditory sense of separation between the timbre and the timbre related to the second waveform signal is reduced. Thereby, the first and second waveform signals are changed audibly smoothly.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of an entire keyboard electronic musical instrument as a musical tone signal generation device to which a signal interpolator according to the present invention is applied. ing.

This keyboard electronic musical instrument is equipped with a key switch circuit 11. This key switch circuit 11 has a plurality of key switches corresponding to each weight of the keyboard, and has a key code KC representing a key pressed on the keyboard and a key-on signal KO' representing the pressed key.
Output N. An address generator 12 is connected to the key switch circuit 11, and the generator 12 generates an address signal that changes at a rate corresponding to the pitch frequency of the pressed key based on the supplied key code KC. waveform memory 1
3.14 to control reading of the same memory 13.14. ' The waveform memories 13 and 14 are for storing waveform data representing musical tones, which are both composed of a plurality of sampling data, and the waveform memory 13 contains waveform data containing many high frequency harmonic components representing the musical tones at the start of sound generation. is memorized,
The waveform memory 14 stores waveform data that does not contain too many high-frequency harmonic components that represent musical tones during the duration of sound generation (at the end). In such a case, these waveform memories 13 and 14 may store waveform data for one period of a musical tone, or may store waveform data for a plurality of periods.

These waveform memories 13 and 14 have low-pass filters 1
5. '16, a band pass filter 17r18 and a bypass filter 21.22 are connected in parallel, and the j filter group 15, 17, 21 converts the musical waveform signal represented by the waveform data from the waveform memory 13 into low and middle ranges. In addition to separating and outputting high frequencies, a group of filters 16,
18 and 22 separate the musical waveform signal represented by the waveform data from the waveform memory 14 into low, middle and high ranges and output them. In such a case, the frequency characteristics of the low-pass filter 15 and the frequency characteristics of the low-pass filter 16, the frequency characteristics of the band-pass filter 17 and the frequency characteristics of the band-pass filter 18, and the frequency characteristics of the bypass filter 21 and the frequency characteristics of the bypass filter 22 are the same. It may be different, or it may be different.

The output of the filter group 15.17.21 is connected to a multiplier 23,
A mixing circuit consisting of 24, 25 and an adder 26 is connected. Multipliers 23, 24, 25 are filter filters 15, 1
7. Interpolation coefficient generator 27, 2 to the musical waveform signal from 21
Each interpolation coefficient signal from 8.31 is multiplied and outputted, and the adder 26 adds and synthesizes each tone waveform signal from each multiplier 2B and 24.25, and outputs the result. Interpolation coefficient generator 2
7.28.31 outputs an interpolation coefficient signal that gradually decreases at different rates of change as shown by solid lines, broken lines, and dashed-dot lines in FIG. 2A as time elapses from the start of musical tones.

A time function generator 32 is connected to the interpolation coefficient generators 27, 28, and 31, and the function generator 32 starts generating musical tones (keyboard interpolation coefficient generator 2.
7, 28.31, and the same coefficient generator 27.28.
31 controls the formation of interpolation coefficient signals.

Further, a mixing circuit consisting of multipliers 33, 34, 35 and an adder 36 is connected to the output of the filter groups 16, 18, 22.
Complement generator 37 for the musical waveform signal from 6.18.22,
The adder 36 adds and synthesizes the tone waveform signals from the multipliers 33, 34, and 35, and outputs the resultant signal. Complement generator 37, 38
゜41 is composed of an inverting circuit, a so-called "1's complement circuit", which inverts each bit of each interpolation coefficient signal from each interpolation coefficient generator 27, 28, 31, and inverts each bit according to the elapse of time from the start of sound generation of musical tones. Interpolation coefficient signals that gradually increase at different rates of change are output as shown by solid lines, broken lines, and dashed-dot lines in FIG. 2B.

An adder 42 is connected to the output of the adders 26 and 36, and the adder 42 adds and synthesizes the tone waveform signals from both adders 26 and 36, and outputs the result. A multiplier 43 is connected to the output of the adder 42, and the multiplier 43 multiplies the musical waveform signal from the adder 42 by the envelope waveform signal from the envelope generator 44 and outputs the result. envelope generator 4
4 is controlled by the key-on signal KON from the key switch circuit 11, and forms and outputs an envelope waveform signal representing the amplitude envelope of the musical tone based on the key-on signal KON.

A D/A converter 45 is connected to the output of the multiplier 43, and the converter 45 converts the supplied digital signal into an analog signal and supplies it to a sound system 46. The sound system 46 includes an amplifier, a speaker, etc., and produces musical tones corresponding to the supplied analog signal.

Next, the operation of the embodiment configured as described above will be explained.

Now, when any key is pressed on the keyboard, the key switch circuit 11 outputs a key code KC and a key-on signal KON in response to the pressed key.

This key code KC is supplied to the address generator 12,
The generator 12 controls the reading of waveform data stored in the waveform memories 13 and 14 at a rate corresponding to the pitch frequency of the pressed key.

As a result, the waveform memory 13.14 outputs musical waveform signals having the pitch frequencies, and the output musical waveform signals are processed by the filter group 15, 17, 21 and the filter groups 16, 18, 22, respectively. Separated into low, mid and high range.

The signal is supplied to a mixing circuit consisting of multipliers 23, 24.25 and an adder 26, and a mixing circuit consisting of multipliers 33, 34.35 and an adder 36, respectively.

On the other hand, the time function generator 32
Based on the key-on signal KON outputted from the key-on signal KON 1, a signal representing the passage of time from the key press is formed and supplied to the interpolation coefficient generators 27, 28.31.
supplies each interpolation coefficient signal shown in FIG. 2A to the multipliers 23, 24, and 25 in accordance with the supply signal,
24. The low frequency range of the musical waveform signal from the waveform memory 13 multiplied by 25 and added and synthesized by the adder 26;
Each frequency component of the middle range and high range is as shown in Fig. 3.
It gradually decreases over time with different change characteristics. Furthermore, the complement generators 37, 38.41 supply the interpolation coefficient signals shown in FIG. 2B to the multipliers 33, 34, 35 in response to the interpolation coefficient signals from the interpolation coefficient generators 27, 28.31. The low, middle, and high frequency components of the musical waveform signal from the waveform memory 14 multiplied by the multipliers 33, 34, and 35 and added and synthesized by the adder 36 are as follows:
As shown in FIG. 3, it gradually increases over time with different change characteristics.

Then, the two tone waveform signals which have been added and synthesized by the adders 26 and 36 are added and synthesized by the adder 42, and after being given an amplitude envelope by the multiplier 43 and the envelope generator 44, D/A conversion is performed. is supplied to the sound system 46 via the
is generated as a musical sound.

As a result of interpolating each waveform signal from the waveform memories 13 and 14 over time in this way, according to the embodiment described above, the musical tones produced from the sound system 46 are based on the waveforms related to the musical waveform signals from the waveform memory 13. The tone waveform signals are gradually changed to those related to the tone waveform signals from the memory 14, and at the time of the change, the two tone waveform signals are mixed with different change characteristics for each frequency band. As a result, at the time of the change, the musical waveform signal from the waveform memory 13 that was previously generated and the waveform memory 1 that will be generated in the future are combined.
The tone waveform signals from 4 are not simply mixed, but the tone waveform signals that have the characteristics of both tone waveform signals and have slightly different frequency components are mixed. It is possible to reduce the auditory sense of separation between the two tone waveform signals.

Note that the present invention can be practiced even if the above embodiment is modified as follows.

(1) In the above embodiment, an example was shown in which the signal interpolator according to the present invention was used to interpolate two types of musical waveform signals over time. It may also be used for signal interpolation depending on the strength of a key touch, the amount of operation of a tone control operator, etc.

In such a case, as shown by the broken line in FIG. 1, the time function generator 32 is activated to generate a function signal (in parentheses in FIGS. 2A and 2B) according to the pitch, the strength of the key touch, or the amount of operation of the timbre control operator. In addition to replacing it with a function generator that generates
The replaced function generator receives the key code KC1 from the key switch circuit 11, the key touch signal KT representing the strength of the key touch detected by the key touch detection circuit 51, or the tone control operation detected by the tone control operator circuit 52. It is sufficient to supply a tone control signal TC representing the operation amount of the child. In such a case, the waveform memories 13 and 14 may each store sampling data representing the entire waveform from the start to the end of sound generation.

(2) In the above embodiment, the change characteristic of interpolation was made linear and at the same time the rate of change was made to increase in the order of low range, middle range, and high range. Alternatively, the order of the rate of change may be reversed, or the rate of change in the middle range may be maximized or minimized. Also,
The rate of change may be the same, but the start timing of the change may be shifted.

(3) In the above embodiment, the musical waveform signal from the waveform memory 13.14 is passed through the low-pass filters 15, 16, the band-pass filters 17.18, and the bypass filter 21.
22, the musical waveform signal can be separated into two types using only a low-pass filter and a bypass filter, or it can be separated into four or more types by further providing multiple band-pass filters with different signal passbands. You may also do so. Further, the filter is not limited to the frequency characteristic filter of the above embodiment, but a filter having two or more types of signal passbands or having complex frequency characteristics may be used.

(4) In the above embodiment, two waveform memories 13 and 14 are used as generation sources of musical waveform signals, and
The output musical waveform signal is switched from the musical waveform signal from the waveform memory 13 to the musical waveform signal from the waveform memory 14, but the generation sources include those generated by FM calculation, those generated by harmonic synthesis calculation, and filtering of the oscillator output. You may also use the one that you made. In addition, 3 such sources
The outputs of the three or more generation sources may be interpolated and sequentially switched and outputted, or the outputs of the three or more generation sources may be interpolated simultaneously.

((5) In the above embodiment, the waveform memory 13.14
Reading operation of waveform data from filters 15° and 16.
17, 18, 21.22 filtering operations, multipliers 23, 24, 25, 33, 34.35 and adder 26,
36.42 operation, interpolation function generator 27, 28.3
Although the operations such as generating the interpolation coefficient signal of 1 are performed in parallel, such operations may be performed in a time-division manner.In particular, regarding filters, arithmetic units for filtering may be used in common. Connecting the arithmetic unit and supplying filter coefficients for the filtering operation in a time-sharing manner,
It is preferable that the two filters have apparently different frequency characteristics on the time axis.

(6) In the above embodiment, the signal interpolator according to the present invention is applied to a musical tone signal generating device that has a keyboard and generates a musical tone signal based on the pressed keys of the keyboard. The present invention is also applied to a musical tone signal generating device that generates a musical tone signal based on key information from. Also,
The present invention is also applied to musical sound signal generating devices such as rhythm sound generating devices that generate sound signals of percussion instruments such as cymbals and bass drums that are not related to keyboard operations.

[Brief explanation of the drawing]

FIG. 1 is an overall block diagram of a musical tone signal generation device to which a signal interpolator is applied, showing one embodiment of the present invention, FIG.
FIG. B is a graph showing an example of the change characteristics of the interpolation coefficient signal, and FIG. 3 is a state diagram showing the change state of the musical waveform signal. Explanation of symbols 13.14...Waveform memory, 15.16...Low pass filter, 17.18...Band pass filter, 2
1.22...Bypass filter, 23~25.33~
35... Multiplier, 26, 36.42... Adder, 2
7, 28.31... Interpolation coefficient generator, 32... Time function generator, 37.38.41... Complement generator.

Claims (1)

[Scope of Claims] Applied to a musical tone signal generating device comprising waveform signal generating means for generating first and second waveform signals having different waveforms at the pitch frequencies of musical tones to be generated, the first waveform By interpolating the signal and the second waveform signal according to musical tone control elements such as elapsed time of sound generation, strength of key touch, pitch of sound, and operation amount of timbre control operator, In a signal interpolator for a musical tone signal generation device that outputs a waveform signal that smoothly changes from the first waveform signal to the second waveform signal according to the change, filter means for separating and outputting the second waveform signal into a plurality of waveform signals having different frequency characteristics; a mixing means for mixing a plurality of waveform signals; and a mixing means for mixing a plurality of waveform signals separated from the first waveform signal according to a change in the musical tone control element, and a mixing ratio of the plurality of waveform signals separated and outputted from the first waveform signal in the mixing means. and a mixing ratio control means for gradually increasing each mixing ratio of the plurality of waveform signals separated and outputted from the second waveform signal in the mixing means with different change characteristics. A signal interpolator for a musical tone signal generator, characterized in that: