JPS6226790Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electronic musical instrument that generates a sound similar to a human voice by key press operation, and is convenient for composing and arranging vocal music, practicing chorus, etc.

Conventional electronic musical instruments generally generate instrumental sounds and cannot perform performances using human voice sounds, so they cannot be fully utilized for composing and arranging vocal music, practicing choruses, and the like.

Therefore, the present inventor first opened and closed the sawtooth wave signal generated by the sound source device using a control signal with a rise time constant of 100 mS to several 100 mS generated in response to a key press, and then output the signal. He devised an electronic musical instrument that could produce a performance sound extremely similar to the human voice by forming and outputting the tone through a fixed formant filter with frequency characteristics for the human voice. -Refer to No. 108042).

By the way, in general, the Japanese vowels "a" and "e"
"I", "O", and "U" are each made up of two or three formants, as shown in FIGS. 1A to 1E. In order to obtain these formants, the above-mentioned invention provided a fixed formant filter dedicated to each vowel. Therefore, if an attempt was made to increase the types of vowels that can be output, a corresponding number of fixed formant filters would be required, resulting in an increase in cost.

This invention aims to solve the above problem by combining multiple series of voltage-controlled variable band filters (hereinafter referred to as [VCF]) and voltage-controlled variable gain amplifiers (hereinafter referred to as [VCA]). A series circuit is provided, and the center frequency of VCF of each series and VCA
To provide an electronic musical instrument that outputs a human voice sound, which is made to act as a formant filter for a desired vowel by controlling the gain of the instrument, and which selection of the vowel can be made with one variable resistor. It is something.

Embodiments of this invention will be described below with reference to the accompanying drawings.

FIG. 2 is a block diagram showing the overall structure of the electronic musical instrument according to this invention. In the figure, 1 is the keyboard circuit,
Pitch control voltage KV and key press signal KON corresponding to key presses
occurs. 2 is a voltage-controlled variable frequency oscillator (hereinafter abbreviated as [VCO]) as a sound source device, which uses a pitch control signal generated by the keyboard circuit 1 to generate a frequency corresponding to the pitch of the pressed key. outputs a sawtooth wave signal S _O.

Reference numeral 3 designates an envelope generator (EG) as an opening/closing control signal generator, which inputs a key press signal KON as shown in FIG. 3B output from the keyboard circuit 1 in response to a key press operation. A control signal with a waveform as shown in Figure A is generated. This control signal reaches the attack level after the key press signal KON is input.
The initial attack time _TA , which is the rise time constant until AL is reached, is set to 100 mS to several 100 mS. 4 is a sawtooth wave signal S _O by the control signal generated by the opening/closing control signal generator 3.
This is a switching circuit that uses a VCA to open and close the circuit.

The musical tone signal S _A whose envelope is formed by opening/closing control by the opening/closing circuit 4 is inputted to a formant forming circuit 5 consisting of a series circuit of three series of VCF and VCA for forming a human voice formant. A formant is formed into the timbre of the selected vowel of the human voice, and the signal S _F is amplified and electro-acoustic converted by a sound system 6 comprising an amplifier, a speaker, etc., and then produced.

VCF and VCA form the first formant with the lowest frequency of each vowel in Figure 1, VCF and VCA form the second formant with an intermediate frequency, and VCF and VCA form the highest frequency formant. Three formants are formed respectively. Therefore, each VCF, , has a fixed passing frequency bandwidth, and its center frequency is determined by the control signals Y, Y, Y generated by the control signal generator (hereinafter referred to as [CSG]) group 7. It operates as a variable band pass filter.
Further, each VCA, . . . is a control signal Y whose gain is generated by the control signal generator group 8.
', Y', and Y'.

Therefore, these control signals Y, Y, Y
By appropriately selecting the voltage values of Y', Y', and Y', this formant forming circuit 5
The musical tone signal S _A inputted to the oscillator can be formed into a desired vowel formant. 9 is a vowel selection circuit consisting of one variable resistor for selecting a vowel of human voice sounds to be generated, and outputs a DC voltage corresponding to each vowel to select the CSG of each CSG group 7, 8,
, , and CSG′,′,′.
Thereby, each CSG group 7, 8 outputs each control signal Y to Y and Y' to Y' of voltage necessary to form the formant of the selected vowel.

Figure 4 shows the contents of the control signal generator (CSG).
This is a block circuit diagram showing a CSG as an example, and FIG. 5 is a circuit diagram showing the voltage selection circuit 10 in more detail.

This control signal generator (CSG) operates for each formant series and the VCF of each formant series shown in Figure 2.
In addition, each VCA is composed of independent and different function generators as described below.

In FIG. 4, 10 is a voltage selection circuit, 11,
12 is a subtraction circuit, 13 is a multiplication circuit, and 14 is an addition circuit. The voltage selection circuit 10 receives a direct current voltage V _D from the vowel selection circuit 9 through a variable resistor VR.
The voltage K output by dividing the voltage and the resistors R ₁ , R ₂ ,
The DC voltage V _D is divided by R ₃ , R ₄ , R ₅ , R ₆ to generate voltages K ₁ , K ₂ , K ₃ ,
K ₄ , K ₅ (K ₁ <K ₂ <K ₃ <K ₄ <K ₅ ), and the DC voltage V _D
voltages _{Y 1 ,} Y ₂ , Y ₃ , _{Y 4 , Y 5 (} in this case _, the vowel "a" A voltage for controlling the center frequency of the VCF is input so that the first formants "E", "I", "O", and "U" are obtained.

As shown in FIG. 5, this voltage selection circuit 10 is comprised of a comparator 15, AND circuits 16, 17, 18 having a negative input terminal and a positive input terminal, and FETs _Q1 to _Q12 as switching elements.

The comparator 15 receives the voltage K input from the vowel selection circuit 9 and the aforementioned voltage generated within the CSG.
_K1 to _K5 are compared, and the following output is obtained depending on the value of voltage K.

When K ₁ ≦K≦K ₂ , a is “1” When K ₂ ≦K≦K ₃ , b is “1” When K ₃ ≦K≦K ₄ , c is “1” K ₄ ≦K≦K ₅ When d becomes “1” and a becomes “1”, FETQ ₁ , Q ₂ , Q ₉
turns on, and voltages Y ₂ ,
Output Y ₁ and K ₁ . Moreover, when a becomes "0" and b becomes "1", the output of the AND circuit 16 becomes "1", FETQ ₃ , Q ₄ , and Q ₁₀ are turned on, and output terminals e, f, and g are respectively supplied. Outputs voltages Y ₃ , Y ₂ , and K ₂ . Similarly, this voltage selection circuit 10 outputs voltages Y _o+1 , Y _o , and K _o to output terminals e, f, and g, respectively, according to the value of the input voltage K (n=1, 2, 3,
4,5).

The voltages Y _o+1 and Y _o outputted from the terminals e and f of the voltage selection circuit 10 are subtracted from the latter by the subtracting circuit 11 to become Y _o+1 -Y _o . Further, the voltage _Ko output from the terminal g is subtracted from the voltage K in the subtraction circuit 12 to become K- _Ko . These Y _o+1 -Y _o and K-K _o are input to the multiplication circuit 13 and multiplied, resulting in (Y _o+1 -Y _o )×(K-K _o ). This is input to the adder circuit 14 and further voltage Y
_o is added, Y=(Y _o+1 −Y _o )(K−K _o )+Y
It is output as _o .

Here, Y=(Yo ₊₁ - _Yo )(K- _Ko )+ _Yo ...(1) will be explained. This equation (1) represents a linear straight line as shown in FIG. The slope of this straight line is (Yo _{+1 -Yo} )/(Ko _{+1 -Ko} ), but if we set Ko _{+1 -Ko} here, the slope is (Yo ₊₁ −Y _o ). K _o and Y _o in equation (1) are values for coordinate transformation of the Y axis and K axis in FIG. 6 so that they pass through point P, respectively.

Since the values of the voltages Y _o+1 , Y _o , and K _o output from the voltage selection circuit 10 change depending on the value of K as described above, equation (1) can be changed as shown in FIG. Y _-1 , Y _-2 , Y _-3 , Y depending on the value of voltage K
_-4 represents four straight lines. That is, when K ₁ ≦K≦K ₂ , Y _-1 = (Y ₂ - Y ₁ ) (K - K ₁ ) + Y ₁ (2) When K ₂ ≦K≦K ₃ , Y _-2 = (Y ₃ - Y ₂ ) (K-K ₂ ) + Y ₂ (3) When K ₃ ≦K ≦ K ₄ , Y _-3 = (Y ₄ - Y ₃ ) (K-K ₃ ) + Y ₃ (4) K ₄ ≦K≦ When K ₅ , Y _-4 = (Y ₅ - _{Y 4} ) (K - K ₄ ) + Y ₄ (5) Then, if K = K ₁ , then from equation (2), Y = Y ₁ , K
If = K ₂ , then Y = Y ₂ from equation 3; if K = K ₃ , then Y = Y ₃ from equation (4); if K = K 4, from equation ( ₅ ), Y = Y ₄ , K = _{If K 5 is used , then from equation ( 5 )} ).

Therefore, if the variable resistor VR is adjusted so that the value of voltage K becomes one of K ₁ to _{K 5} , a control signal of one of voltages Y ₁ to _{Y 5} will be output from CSG accordingly. The center frequency of the VCF can be controlled so as to form the first formant of a desired vowel.

Similarly, in other control signal generators (CSG), voltages Y ₁ to Y ₅ are set to values for controlling the center frequency of VCF so as to form the second and third formants of each vowel. CSG′,
The voltages Y ₁ to _{Y 5} at ′, ′ are the first of each vowel,
If the gain of VCA, , is adjusted to a value to control the level of the second and third formants, the vowel selection circuit 9 can control the voltage K.
All control signals Y~Y, just by selecting the value of
and voltages Y' to Y' are set. Then, when the voltage K is K ₁ , K ₂ , K ₃ , K ₄ , and K ₅ , the vowels "a", "e", "i", "o", and "u" can be generated, respectively.

Furthermore, by continuously changing the voltage K, the value of each control signal changes in the same manner as in equation (1), and an intermediate formant can be formed to generate a human voice sound between each vowel.

As explained above, according to this invention, in an electronic musical instrument that outputs human voice sounds, there is no need to provide a dedicated fixed formant filter for each vowel in order to be able to select from a wide variety of vowels. By providing a series circuit of a plurality of series of VCFs and VCAs and controlling each of the VCFs and VCAs with one variable resistor, it is possible to output human voice sounds with various vowels. Therefore, it also has the effect of being cheaper.

[Brief explanation of the drawing]

Figure 1 A to E are the Japanese vowels "A" and "E" respectively.
A diagram showing the formant structure of “i”, “o”, and “u”,
Figure 2 is a block diagram showing an embodiment of this invention.
Figure 3 is a waveform diagram showing the relationship between the key press signal and the control signal waveform, Figure 4 is a block diagram showing the contents of the control signal generation circuit (CSG) in Figure 2, and Figure 5 is the voltage selection in Figure 4. A circuit diagram showing a specific example of the circuit 10, and FIGS. 6 and 7 are diagrams for explaining the operation of the circuit shown in FIG. 4. 1... Keyboard circuit, 2... Voltage controlled variable frequency oscillator (sound source device), 3... Switching control signal generator (EG), 4... Opening/closing circuit, 5... Formant forming circuit, 7, 8... Control signal generator group, 9... Vowel selection circuit, 10... Voltage selection circuit, 11, 12
...subtraction circuit, 13 ... multiplication circuit, 14 ... addition circuit, 15 ... comparator.

Claims (1)

[Scope of utility model registration request] A sound source device that generates a sawtooth wave signal with a frequency corresponding to the pitch, and a rise time constant that corresponds to the key press operation.
A switching control signal generator that generates a control signal of 100 mS to several 100 mS; a switching circuit that opens and closes the sawtooth wave signal according to the control signal generated by the switching control signal generator; A series circuit of a plurality of series of voltage-controlled variable band filters and a voltage-controlled variable gain amplifier, which are provided on the output side and form each formant of the human voice, and a center frequency and voltage of each series of voltage-controlled variable band filters. A control signal generator that generates a control voltage as a control signal for controlling the gain of a controlled variable gain amplifier, and one variable resistor that supplies a DC voltage corresponding to each vowel to this control signal generator. and the control signal generator is composed of independent and different function generators for each of the faultmant series, the voltage-controlled variable band filter, and the voltage-controlled variable gain amplifier of each series, and each of the above-mentioned What is claimed is: 1. An electronic musical instrument that outputs human voice sounds, characterized in that it generates different control voltages for each vowel in response to DC voltages supplied by variable resistors.