JPS62198900A - Electronic musical apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronic musical instrument that samples and stores external sounds.

[Prior art and its problems 1 Conventionally, external sounds, such as a dog's bark or the sound of metal being hit, were sampled at appropriate intervals, the waveform of that sound was memorized, and this was used as a sound source for a musical instrument. What is performed is realized.

In order to reproduce sounds that take advantage of the characteristics of external sounds using such sampling electronic musical instruments, the sampling period must be shortened according to the sampling theorem to capture even minute changes in the external sounds, which would require a huge amount of memory capacity. The problem was that it became necessary.

[Object of the Invention] This invention was made in view of the above-mentioned circumstances, and its purpose is to utilize the characteristics of external sound with a small storage capacity and a simple circuit. Our goal is to provide an electronic musical instrument that can almost faithfully reproduce the following.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention extracts and stores an envelope of a waveform component in a frequency band that is a characteristic part of an external sound, and uses this envelope as a musical tone generation signal. The main point is that the envelope of the frequency component of the musical sound waveform is controlled based on the envelope and the sound is emitted.

[Summary of the Invention] FIG. 1 shows a schematic configuration of an electronic musical instrument according to the present invention, in which an external sound signal from an external sound input terminal 1 is processed by a waveform component extracting means 2 to extract a frequency band representing a characteristic part of the external sound. The waveform component is extracted, the envelope of this waveform component is extracted by the component envelope extraction means 3, and the A-D
C (analog-to-digital) conversion and stored in the component envelope storage means 5. In this writing, the rising edge of the signal from the -F external sound input terminal l from the rOJ level is detected by the sampling control section 6, and in response, the address control section 7 sends the write signal to the component envelope storage means 5. A writing means 8 is constituted by the sampling control section 6 and the address control section 7, in which the leading address is incremented.

[Configuration of Example] Figure 2 shows the overall circuit configuration of an electronic musical instrument.
Reference numeral 1 designates an external sound input terminal, and an external sound signal from a microphone (not shown) is passed through a bandpass filter 12 to extract a waveform component in a frequency band representing a characteristic part of the external sound, and is provided to a component envelope extraction circuit 13. The bandpass filter 12 has a Kerr/ ) off frequency controlled by a control voltage, and this control voltage can be changed by a control signal generating type 2t14.
Depending on the type of external sound, it is possible to select a frequency band that shows its characteristic parts.

In the component envelope extraction circuit 13, as shown in FIG. 2, the output terminal of the bandpass filter 12 is connected to a child terminal of an operational amplifier OA via a capacitor Ct, and the child terminal of this operational amplifier is grounded through a resistor R1. The pulsation of the waveform component from the bandpass filter 12 is filtered out and input to the child terminal of the operational amplifier OA. The 7th node side of a diode D is connected to the output terminal of the operational amplifier OA, and the cathode side of this diode D is grounded via a capacitor C2 and also via a resistor R2.
Further, it is fed back into one terminal of the operational amplifier OA. Therefore, the output of the operational amplifier OA is connected to the diode D,
It is smoothed by a smoothing circuit consisting of a capacitor C2 and a resistor R2, and only when the waveform component from the bandpass filter 12 is larger than this smoothed output, the level of the smoothed output increases, and the component waveform from the bandpass filter 12 increases. A waveform enveloping the peak point on the plus side is obtained, and this is given to the sampling and holding circuit 15 as a component envelope.

In the sampling hold circuit 15, the component envelope is sampled with a sampling signal having a frequency of IKHz, A/D (analog to digital) conversion is performed in an A/D converter 16, and the resultant signal is written into the component envelope storage circuit 17.

Further, the external sound signal from the external sound input terminal 11 has its high frequency components cut off by a low-pass filter 18, is sampled by a sampling and hold circuit 19 with a sampling signal having a frequency of 1OKH7, and is sent to an A/D converter 20 by an A-D converter 20. The data is converted (DC analog to digital) and written into the waveform memory 21.

The waveform memory 21 may store all waveform data, or may store only a portion of the waveform data.

The waveform data is passed through a D/A converter 22, a control filter 23 filters out the amount of passage of a part of the frequency band, and the sound system 24 outputs the sound. When data is stored, it is read out and given to the D/A converter 22. The control filter 23 is of the VCF (voltage controlled filter) type in which the amount of attenuation in the passband is controlled by a control voltage, and for example, a fixed filter is used.
A control voltage corresponding to the component envelope read out from 7 is applied from the filter control device 25, and the amount of passage of the waveform component in the same frequency band as the frequency band extracted by the bandpass filter 12 is determined by the amount of attenuation in this band. Opened by fluctuations.

In writing the component envelope and waveform, the external sound signal from the sampling and hold circuit 19 is given to the level detection circuit 26, and the external sound signal is "0".
” level is detected and the start signal is C.
given to PU27. A write start command is given from the CPU 27 to the address controllers 28 and 29, the write start address given to the component envelope storage circuit 17 and the waveform memory 21 is incremented, and a write command signal is given. Also, when reading out the component envelope and waveform, a read address and a read command signal are given from the address controller 28.29 under the control of the CPU 27, and the increment speed of this read address is adjusted to the pitch according to the operation key of the keyboard 30. Determined based on This write and read mode setting is
Recording switch 31, playing switch 32
This is performed by a switch-on signal given to the CPU 27 by the CPU 27.

The level detection circuit 26, CPU 27, and address controller 28 constitute the M-containing means 8 shown in FIG.
14 constitutes the waveform component extracting means 2 of FIG.

[Operation of the embodiment] Next, the operation of this embodiment will be described.

Now, assume that the recording switch 31 is turned on and an external sound signal is input from the external sound input terminal 11, and the bandpass filter 12 outputs a frequency band representing the characteristic part of the external sound as shown in FIG. 3 (1). It is assumed that the waveform component of is outputted and given to the component envelope extraction circuit 13. Then, from the component envelope extraction circuit 13, the third
A component envelope enveloping the positive peak point of the component waveform as shown in FIG. 2 is output and applied to the A/D converter 16 via the sampling and holding circuit 15. The A/D converter 16 outputs a component envelope with a sampling width of IKHz, as shown in FIG. 3(3), and writes it into the component envelope storage circuit 17.

At the same time, the external sound signal from the external sound input terminal 11 is passed through a low-pass filter 18, a sampling hold circuit 19,
An example of this is shown in FIG. 4 (1), in which the data is directly written into the waveform memory 21 via the A/D converter 20 with a sampling width of 10KH2.

Then, when the playing switch 32 is turned on and a key corresponding to a specific scale on the keyboard 30 is operated,
The component envelope is read out from the component envelope storage circuit 17 and given to the filter control S device 25, and a control voltage signal corresponding to the change in the component envelope is given from the filter control W device 25 to the control filter 23. , the waveform data read out from the waveform memory 21 as shown in FIG. 7JRm is performed according to the component envelope and the sound is output.

In this way, without storing the entire waveform in the waveform memory 21, the waveform can be used according to the frequency envelope that indicates the characteristics of the waveform.
By repeatedly reading out a waveform in a predetermined range and applying filter control to it, the sound is emitted while faithfully reproducing the original sound. Of course, by using the operation keys of the keyboard 30,
By varying the control v4 frequency band of the filter 23, more suitable sound can be obtained.

In this embodiment, since the control signal generator 14 allows the passband of the bandpass filter 12 to be arbitrarily selected, it is possible to accurately select the frequency band that is characteristic of each external sound depending on the type of external sound. can.

In the above embodiment, the waveform data of the external sound is given to the control filter 23, but it is also possible to give the control filter 23 a musical tone signal from a musical tone generation circuit normally used for 'ilt child instruments, The number of component envelopes to be extracted is not limited to one, but may cover two or more frequency bands.

[Effects of the Invention] As described in detail above, the present invention extracts and stores the envelope of a waveform component in a frequency band that is a characteristic part of an external sound, and uses this envelope as a generation element of a musical sound. Based on the envelope, the envelope of the frequency component of the musical sound waveform is controlled and emitted, so a large-scale memory is used to reproduce the sound that takes advantage of the characteristics of the external sound. The effect is that it can be executed without any trouble.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an outline of the present invention, Fig. 2 is an overall block circuit diagram of an electronic musical instrument, Fig. 3 is a diagram showing a specific example of component envelope extraction, and Fig. 4 is a specific example of simple recording of waveform data. FIG. 12...Band pass filter, 13...
- Component envelope extraction circuit, 14... Control signal generator, 17... Component envelope storage circuit, 21... Waveform memory, 23... Control filter, 24...Sound system, 25
... Filter control device, 26 ... Level detection circuit, 27 ... CPU, 28.29 ...
...address controller. Patent applicant Casio Computer Co., Ltd. Figure 3 Figure 4

Claims (3)

[Claims] (1) A waveform component extraction means for extracting a waveform component in a frequency band that is a characteristic part of an external sound; a component envelope extraction means for extracting an envelope of the waveform component extracted by the waveform component extraction means; and a component envelope extraction means for extracting the envelope of the waveform component extracted by the waveform component extraction means. The component envelope storage means has a component envelope storage means for storing the component envelope extracted by the means, and a writing means for writing the component envelope into the component envelope storage means, and the component envelope is used as a generating element of a musical tone. An electronic musical instrument characterized by: (2) a waveform component extracting means for extracting a waveform component in a frequency band that is a characteristic part of an external sound; a component envelope extracting means for extracting an envelope of the waveform component extracted by the waveform component extracting means; a component envelope storage means for storing the component envelope extracted by the component envelope storage means; a writing means for writing the component envelope into the component envelope storage means; a waveform generation means for generating a musical sound waveform; The present invention includes an envelope control means for controlling frequency components of a waveform based on an envelope from the envelope storage means, and a sound emitting means for emitting a musical tone according to the waveform controlled by the envelope control means. Characteristic electronic musical instruments. (3) The electronic musical instrument according to claim 2, wherein the waveform generating means is means for storing at least a part of the waveform of the applied external sound, reading out and outputting the waveform.