JP7189960B2 - playing device - Google Patents

Description

The present invention relates to a performance device .

2. Description of the Related Art Conventionally, performance devices such as FM synthesizers are known as electronic musical instruments (see, for example, Patent Document 1).
An FM synthesizer modulates a carrier wave oscillated from a first oscillator with a modulating wave oscillated from a second oscillator to generate various acoustic signals. Then, based on keynotes input from an electronic keyboard or the like connected to the FM synthesizer, it is possible to output an acoustic signal having a musical scale.

However, with an FM synthesizer, there are an infinite number of possible combinations of carrier waves and modulated waves, and depending on the combination of oscillator adjustments, the pitch will not be fixed regardless of the keying position on the electronic keyboard, and it will be buried in noise. sometimes not.
Conventionally, Patent Literature 2 discloses a technique for clarifying the speech component of an output audio signal by performing filtering on a specific frequency band from an audio signal containing a speech component and a noise component.

JP-A-4-161994 JP 2010-521704 A

However, the technique disclosed in Patent Document 2 can only remove noise components such as environmental noise whose frequency band is known to some extent. On the other hand, in the case of an FM synthesizer, since the frequencies of the carrier wave and the modulated wave can be freely set, there is a problem that the generation distribution of noise components is not uniform and cannot be dealt with by filtering.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a musical performance apparatus capable of removing noise irrespective of the distribution of noise component generation and outputting an acoustic signal having a frequency corresponding to an operator's operation.

A musical performance apparatus according to the present invention is a musical performance apparatus that outputs an acoustic signal having a frequency corresponding to an operation by an operator, wherein the signal strength of a noise signal other than the frequency of the acoustic signal corresponding to the operator's operation is detected. A signal detection unit and a noise signal reduction unit that attenuates or eliminates the signal strength of the noise signal detected by the noise signal detection unit.
A noise reduction program of the present invention causes a computer to function as the above-described performance device.

1 is a block diagram showing an acoustic device according to an embodiment of the present invention; FIG. The top view which shows the structure of the adjustment knob in the said embodiment. Sectional drawing which shows the structure of the adjustment knob in the said embodiment. FIG. 2 is a block diagram showing the structures of an acoustic signal generator and an acoustic signal synthesizer in the embodiment; 4 is a graph showing signal strength of an acoustic signal generated according to the waveform of the modulated wave in the embodiment; 4 is a graph showing the signal intensity of the synthesized acoustic signal in the embodiment; FIG. 2 is a block diagram showing an acoustic signal generator, an acoustic signal synthesizer, a signal strength estimator, and a limit amount annunciator in the embodiment; FIG. 3 is a block diagram showing a signal strength estimating section and a limit amount reporting section in the embodiment; FIG. 2 is a block diagram showing the noise reduction section in the embodiment; 4 is a graph showing analysis results by the noise component analysis unit in the embodiment; 5 is a graph showing noise attenuation by the noise reduction section in the embodiment; 4 is a flow chart for explaining the operation of the embodiment;

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an FM (Frequency Modulation) synthesizer 1 according to an embodiment of the invention.
An FM synthesizer 1 as a performance device includes a synthesizer main body 2 and an adjustment operation unit 3, generates an acoustic signal with a pitch corresponding to a keynote output from a MIDI keyboard 4, and outputs the sound to the outside. The adjustment operation unit 3 is provided with a plurality of adjustment knobs 32 for adjusting the gains and frequency ratios of the oscillators of the synthesizer main body 2. By operating the respective adjustment knobs 32, the operator operates the FM synthesizer section 6 for sound output. to generate acoustic signals of different tones.

The adjustment operation unit 3 has a box-shaped case 31 and a plurality of adjustment knobs 32 . In this embodiment, 4×4=16 adjustment knobs 32 are provided corresponding to the adjustable acoustic signal generators OP1 to OP4 of the synthesizer body 2 .
The adjustment knob 32 as an adjustment operation unit is rotatably provided on the upper surface of the case 31, and includes an operation knob main body 321, an adjustment position display marker 322, and a knob base 323, as shown in FIGS.

The operation knob main body 321 is made of an opaque material such as black rubber, and is rotatably held on the case 31 .
The adjustment position indicator marker 322 and the knob base 323 are made of a light-guiding material such as a lens material. In other words, the adjustment position display marker 322 and the knob base 323 are light guides that emit light around the operation knob main body 321 and the adjustment position display marker 322 according to the color of light emitted by an LED light emitting unit 327, which will be described later. function as

The adjustment position display marker 322 is inserted into a notch formed in the operation knob main body 321 and allows the operator to visually recognize the adjustment amount when the operation knob main body 321 is rotated.
The knob base 323 is provided at the bottom of the operation knob main body 321 and is supported so as to rotate as the operation knob main body 321 rotates. In addition, the knob base 323 protrudes outward from the operation knob main body 321 at its radially outer peripheral end.

A rotary shaft 324 is provided at the rotation center of the knob base 323 , and the tip of the rotary shaft 324 is connected to a rotary resistor 326 provided on a circuit board 325 . The rotary resistor 326 is provided adjacent to an LED light emitting portion 327 that emits light in a plurality of colors.
The LED light emitting section 327 as a visual means is driven by a control signal from the synthesizer main body 2, and emits light in various colors by emitting red, green, and blue light alone or in combination according to the control signal.

The adjustment knob 32, the rotating shaft 324, the rotating resistor 326, and the LED light emitting section 327 function as the feature quantity adjusting section of the present invention.
Although the adjustment operation unit 3 is configured as hardware in the present embodiment, it is not limited to this. For example, it may be a feature amount adjustment unit configured as an image displayed on a computer screen.

As shown in FIG. 1, the synthesizer main body 2 generates an acoustic signal of a scale corresponding to the input keynote KNOTE, and outputs the sound. The synthesizer main body 2 includes a parameter selection section 5 , a sound output FM synthesizer section 6 , an analysis FM synthesizer section 7 , a noise component analysis section 8 and a noise reduction section 9 .
The parameter selection section 5 is a section that selects the waveform of the acoustic signal generated and output by the synthesizer body 2. Examples of selectable waveforms include a sine wave W1, a triangular wave W2, a sawtooth wave W3, and a rectangular wave W4. (See Figure 5). The selected waveform, frequency ratio, gain of the input side amplifier 64A and gain of the output side amplifier 63A are output to the FM synthesizer section 6 for sound output and the FM synthesizer section 7 for analysis.

As shown in FIG. 4, the sound output FM synthesizer section 6 is composed of a DSP (Digital Signal Processor), and includes a plurality of sound signal generation sections OP1 to OP4.
The acoustic signal generators OP1 to OP4 generate acoustic signals to be output based on the carrier wave and modulated wave used in the FM synthesizer unit 6 for sound output.
The acoustic signal generator OP1 includes an oscillator 61, an amplifier 62, a signal output section 63, an output side amplifier 63A, and a modulated wave input section 64. The acoustic signal generator OP2 to the acoustic signal generator OP4 have the same configuration.

The oscillator 61 generates a carrier wave having a predetermined frequency ratio from the waveform selected by the parameter selection section 5, and modulates the carrier wave with the input modulating wave. Specifically, the oscillator 61 generates a carrier wave having a frequency corresponding to the key note KNOTE input from the MIDI keyboard 4, and modulates it with the modulating wave.
For example, if the modulated wave is a sine wave W1 as shown in FIG. Modulate with a ratio sine wave W1. The signal intensity of the acoustic signal output after modulation has a pattern PT1 peaking at the frequency f_in corresponding to the keynote KNOTE.

Similarly, when the modulated wave is the triangular wave W2, the signal intensity of the modulated output acoustic signal is as shown in the pattern PT2, and when the modulated wave is the sawtooth wave W3, the modulated output acoustic signal is The signal intensity has a pattern PT3, and when the modulated wave is a rectangular wave W4, the signal intensity of the acoustic signal output after modulation has a pattern PT4.
That is, when the carrier wave is modulated by the modulating wave, an acoustic signal having a signal intensity peak at a frequency other than the frequency f_in corresponding to the keynote KNOTE is generated depending on the waveform of the modulating wave.

Amplifier 62 amplifies the acoustic signal output from oscillator 61 . The amplification factor is set according to the strength of keystrokes on the MIDI keyboard 4 included in the keynote KNOTE.
The signal output section 63 outputs the acoustic signal generated by the oscillator 61 to the acoustic signal synthesizing section 65 . Further, the acoustic signal output from the signal output unit 63 is fed back to the modulated wave input unit 64 of the acoustic signal generation unit OP1, and the other acoustic signal generation unit OP2, the acoustic signal generation unit OP3, and the acoustic signal generation unit It is output to the modulated wave input section 64 of OP4.

Similarly, the acoustic signals output from the signal output units 63 of the acoustic signal generator OP2, the acoustic signal generator OP3, and the acoustic signal generator OP4 are also fed back to their own modulated wave input units 64, It is output to the modulated wave input section 64 of the acoustic signal generation section.
The modulated wave input section 64 includes a plurality of input side amplifiers 64A and input side adders 64B.
A plurality of input-side amplifiers 64A are provided according to the input acoustic signal. In the case of the acoustic signal generation unit OP1, the feedback acoustic signal output by itself and the other acoustic signal generation unit OP2 to the acoustic signal generation unit It amplifies the input acoustic signal generated in OP4. The amplification factor can be adjusted by adjusting the adjustment knob 32 of the adjustment operation unit 3 .
The input side adder 64B adds a plurality of acoustic signals input from the input side amplifier 64A and outputs the result to the oscillator 61 as a modulated wave.

In this embodiment, since the four acoustic signal generators OP1 to OP4 are provided, the acoustic signals amplified by the four input amplifiers 64A provided in front of the respective four oscillators 61 are Adjust the intensity of the to output the final acoustic signal. That is, in the present embodiment, 16 adjustments are possible, corresponding to the number of adjustment operation knobs 32 of the adjustment operation unit 3 .
In the present embodiment, since the FM synthesizer 1 includes the multi-input, single-output acoustic signal generators OP1 to OP4, it is possible to generate acoustic signals with a wide variety of timbres. However, on the other hand, it is impossible to predict how the adjustment operation unit 3 should be operated to generate an acoustic signal with a desired tone color, making the synthesizer extremely difficult for the operator to perform adjustment operations.

The signal output unit 63 outputs the acoustic signals generated by the acoustic signal generators OP1 to OP4.
The output amplifier 63A amplifies the acoustic signals generated by the acoustic signal generators OP1 to OP4 with a predetermined amplification factor. The amplification factor can be adjusted by adjusting the adjustment knob 32 of the adjustment operation unit 3 .

The acoustic signal synthesizing unit 65 adds or multiplies the acoustic signals output from the acoustic signal generating units OP<b>1 to OP<b>4 , and outputs the result as an acoustic signal for the FM synthesizer 1 . The acoustic signal synthesizing section 65 includes an adder 66 , a filtering section 67 and an amplifier 70 .
The adder 66 adds the acoustic signals output from the acoustic signal generator OP1 to the acoustic signal generator OP4 to generate a synthetic acoustic signal for audio output.

The filter unit 67 filters the synthesized sound signal added by the first adder 66 . The filter of the filter section 67 is set to have desired filter characteristics in order to process the acoustic signal into a desired timbre.
The amplifier 70 amplifies the synthesized acoustic signal to be output. The amplified synthetic sound signal is output as sound by a speaker or the like.

The synthesized acoustic signal to be output varies depending on the waveform and frequency ratio of the oscillators 61 of the acoustic signal generators OP1 to OP4, the amplification factor of the output side amplifier 63A, and the amplification factor of the input side amplifier 64A. For example, as the synthesized sound signal, a synthesized sound signal having a frequency different from the frequency f_in corresponding to the input keynote KNOTE is output. For example, as shown in FIG. 6, when modulated by a sine wave W1, the frequency f_in takes the maximum value as in the output intensity pattern PO1, and the signal intensity of the frequency becomes Attenuating. Therefore, the listener can identify the scale of the output synthetic sound signal.

However, from the output intensity pattern PO2 modulated by the triangular wave W2 to the output intensity pattern PO4 modulated by the rectangular wave W4, the signal intensity of the frequency f_in corresponding to the keynote KNOTE is gradually buried in the signal intensity of the other frequencies. , cannot output the pitch according to the keynote KNOTE. In other words, no matter what keys the operator presses on the MIDI keyboard 4, only high-frequency noise sounds are output, and the instrument fails.
Therefore, the FM synthesizer 1 of the present embodiment is provided with a navigation function that can be operated so that the synthesized sound signal to be output is only high-frequency noise sound and the instrument fails.

As shown in FIG. 7, the analysis FM synthesizer unit 7 includes a plurality of sound signal generation units OP1′ to OP4′ configured by DSPs in the same manner as the sound output FM synthesizer unit 6, and an output side amplifier. 72A, an adder 74, a signal strength estimation unit 75, and a limit amount notification unit 76.
Each of the acoustic signal generator OP1' to the acoustic signal generator OP4' includes an oscillator 71, a signal output section 72, and a carrier signal input section 73. FIG. The carrier signal input section 73 has an input side amplifier 73A and an input side adder 73B.

These configurations are similar to those of the acoustic signal generators OP1 to OP4 of the FM synthesizer section 6 for sound output. A test keynote TNOTE generated in the synthesizer body 2 is input to each oscillator 71 , and the oscillator 71 generates a carrier wave corresponding to the frequency of the test keynote TNOTE by adjusting a plurality of adjustment knobs 32 . It modulates with a modulated wave generated according to the state.
The adder 74 adds or multiplies the acoustic signals respectively generated by the acoustic signal generators OP1′ to OP4′, and outputs the result to the signal strength estimator 75 as a synthesized acoustic signal.

The signal strength estimating section 75 and the limit amount reporting section 76 are configured as a program executed on an arithmetic processing unit of a computer (not shown) or a storage area secured on a storage device.
The signal strength estimation unit 75 includes a test keynote output unit 751, a synthesized sound signal detection unit 752, an operation amount change unit 753, a limit amount determination unit 754, and an adjustment knob selection unit 755, as shown in FIG. Further, the signal strength estimating section 75 outputs the number of each adjustment knob 32 of the adjustment operation unit 3 and the adjustment operation amount of the adjustment knob 32, and is used for limit amount judgment by the limit amount judgment section 754 described later. be.

The test keynote output unit 751 outputs a test keynote TNOTE to the sound signal generation units OP1' to OP4'. The acoustic signal generators OP1′ to OP4′ generate acoustic signals based on the test keynote TNOTE.
Further, the test keynote output unit 751 outputs the frequency corresponding to the output test keynote TNOTE to the limit amount determination unit 754 .

The adjustment knob selection unit 755 selects the adjustment knob 32 for adjusting the oscillator 71 from among the sound signal generation units OP1′ to OP4′. Specifically, the adjustment knob selection unit 755 selects the oscillator 71 to be adjusted, the modulated waveform of the oscillator 71, the intensity and frequency ratio of the output acoustic signal, and the Select the adjustment knob 32 that adjusts the strength of the acoustic signal. The adjustment knob selection section 755 outputs the selected adjustment knob 32 to the limit amount determination section 754 .

The synthesized sound signal detection unit 752 detects a synthesized sound signal obtained by synthesizing the sound signals generated by the sound signal generation units OP1′ to OP4′ added by the adder 74. FIG.
The synthesized acoustic signal detection unit 752 converts the detected synthesized acoustic signal into signal strength according to frequency by FFT (Fast Fourier Transform) or the like, acquires the signal strength distribution, and outputs the signal strength distribution to the limit amount determination unit 754. .

The operation amount changing unit 753 transmits the waveform, frequency ratio, and amplification of the modulated wave of each oscillator 71 from the sound signal generation unit OP1′ to the sound signal generation unit OP4′ in the same manner as the adjustment operation of the adjustment knob 32 of the adjustment operation unit 3. and the adjustment operation amount of the amplification factor of the input side amplifier 73A. Specifically, the operation amount changing section 753 outputs a combination of adjustment operation amounts of all the adjustment knobs 32 as an adjustment operation amount according to the adjustment amount of each adjustment knob 32 of the adjustment operation unit 3 .
Further, the manipulated variable changing unit 753 outputs to the limit amount determining unit 754 the adjustment manipulated variable output from the acoustic signal generating unit OP1′ to the acoustic signal generating unit OP4′.

The limit amount determining section 754 determines the waveform of the modulated wave, the frequency ratio, the amplification factor of the output side amplifier 72A, and the amplification factor of the input side amplifier 73A, which are set based on the adjustment operation amount output from the operation amount changing section 753. It is determined whether or not the synthesized sound signal modulated by is broken when it is output as a sound. Specifically, the limit amount determination unit 754 uses the frequency corresponding to the test keynote TNOTE as the fundamental frequency, and determines the signal intensities of the fundamental tone, the second overtone, and the third overtone, and the other frequencies contained in the synthesized sound signal. Based on the S/N ratio with the signal strength of the frequency component, it is determined whether or not the synthesized sound signal to be output is broken. When the S/N ratio between the signal strength of the fundamental tone and overtones and the signal strength of other frequency components contained in the synthesized sound signal is smaller than a predetermined threshold, with the frequency corresponding to the test keynote TNOTE as the fundamental frequency. , it is determined that the adjustment operation amount exceeds the limit amount and is broken.

Here, the synthesized sound signals generated by the sound signal generation units OP1′ to OP4′ are different from the sound signals generated by the same settings as those of the sound output FM synthesizer unit 6. The same setting as the setting of the synthesizer section 6 is generated by the setting when the adjustment knob 32 is operated at one position.
At this time, the adjustment operation unit 3 is in a state of operating the four oscillators 61 and the four input amplifiers 64A and 73A provided in the preceding stages of the oscillators 71, respectively. These 16 parameters can be adjusted by the 16 adjustment operation knobs 32 of the adjustment operation unit 3 .

When the operator operates one adjustment knob 32, in addition to the operation, when one of the adjustment knobs 32 is operated to a predetermined position, the sound signal generation unit OP1' is changed to the sound signal generation unit. OP4' generates a synthesized sound signal according to the operating position of the adjustment knob 32. FIG.
A limit amount determination unit 754 analyzes the synthesized sound signal and determines whether or not the limit amount has been reached.
The limit amount of the adjustment operation amount of each adjustment knob 32 determined by the limit amount determination unit 754 is output to the limit amount notification unit 76 .

The limit amount notification section 76 includes a control signal output section 761 and a notification state storage section 762 .
The control signal output unit 761 generates a lighting control signal based on the limit amount of the adjustment operation amount output from the limit amount determination unit 754, and outputs the lighting control signal to the LED light emission unit 327 of each adjustment knob 32 of the adjustment operation unit 3. Output. Specifically, the control signal output unit 761 outputs a control signal that causes the LED light emitting unit 327 to emit green light when the adjustment operation amount of the adjustment knob 32 is equal to or less than the limit amount.

Further, the control signal output section 761 outputs a control signal for causing the LED light emitting section 327 to emit light in red when the adjustment operation amount of the adjustment knob 32 exceeds the limit amount.
In addition, the emission color of the LED light emitting unit 327 is not limited to two colors, and may be green when the adjustment operation amount is sufficiently smaller than the limit amount, yellow when the amount is close to the limit amount, and red when the limit amount is exceeded. It may be configured to display in multiple stages.

The notification state storage unit 762 is configured as part of a storage area of a recording medium such as memory. The notification state storage unit 762 stores the limit amount of the adjustment operation amount of the adjustment knob 32 determined by the limit amount determination unit 754 . When the limit amount of the adjustment operation amount of each adjustment knob 32 is calculated, the limit amount determination unit 754 rewrites the previous limit amount to a new limit amount of the adjustment operation amount.

The noise component analysis unit 8 analyzes noise components contained in the synthesized sound signal based on the synthesized sound signal output from the analysis FM synthesizer unit 7 . The noise component analysis unit 8 includes a test keynote acquisition unit 81, a noise signal detection unit 82, a noise component accumulation unit 83, and a different scale setting unit 84, as shown in FIG.
The test keynote acquisition unit 81 acquires the test keynote TNOTE output from the test keynote output unit 751 of the signal strength estimation unit 75 .

The noise signal detection unit 82 detects the distribution of signal strength according to the frequency of the synthesized sound signal detected by the synthesized sound signal detection unit 752 . The noise signal detection unit 82 detects the fundamental tone and overtones with the frequency corresponding to the acquired test keynote TNOTE as the fundamental frequency (if the frequency ratio is set to a value other than an integer, the frequency is adjusted to the frequency corresponding to the test keynote TNOTE). A peak of signal strength occurring at a frequency other than the fundamental tone and overtones with the frequency multiplied by the ratio as the fundamental frequency is detected as a noise component. For example, as shown in FIG. 10, the noise signal detection unit 82 uses the frequency f_in' corresponding to the test keynote TNOTE as the fundamental frequency, and detects the signal intensity from the peak N1 to the peak of the signal strength other than the fundamental tone, the second overtone, and the third overtone. N4 is detected as a noise component.
The noise component accumulation unit 83 accumulates the noise components detected by the noise signal detection unit 82 in a storage area such as a memory as noise components corresponding to the test keynote TNOTE.

The different scale setting unit 84 sets an acoustic signal having a frequency different from the acoustic signal having the fundamental frequency according to the operator's operation. The signal strength peaks of different frequencies set by the different scale setting unit 84 are not regarded as noise components to be detected by the noise signal detection unit 82 described above, and the frequency f_in' corresponding to the test keynote TNOTE is used as a basis. Fundamental tone and overtones with frequency (in the case of setting a frequency ratio other than an integer, the fundamental tone and overtones with the frequency obtained by multiplying the frequency fin corresponding to the test keynote TNOTE by the frequency ratio) are treated in the same way. Specifically, when the code "C" is set as the different scale by the different scale setting unit 84, when the operator presses "do" on the MIDI keyboard 4, "mi" and "so" are similarly generated. It is no longer regarded as a noise component and is excluded from detection targets of the noise signal detection section 82 .
As a result, even if the operator presses a single note on the MIDI keyboard 4, the outputted sound signal can be a chord, so that a pleasant chord can be played.

The noise reduction unit 9 attenuates or eliminates noise components contained in the synthesized sound signal output from the sound output FM synthesizer unit 6, and converts the frequency corresponding to the keynote KNOTE input from the MIDI keyboard 4 into the fundamental frequency. (In the case of frequency ratio settings other than integers, the fundamental tone and overtones with the frequency obtained by multiplying the frequency according to the test keynote TNOTE by the frequency ratio) are output. The noise reduction section 9 includes an input keynote determination section 91 and a noise signal reduction section 92 .
The input keynote determination unit 91 determines the keynote KNOTE input by the operator by operating the MIDI keyboard 4, compares it with the test keynote stored in the noise component storage unit 83, and determines the keynote for test. Using the corresponding frequency as the fundamental frequency, the noise component of peaks N1 to N4 of the signal intensity other than the fundamental tone, second overtone, and third overtone is read out. The input keynote determination section 91 outputs the read noise component to the noise signal reduction section 92 .

The noise signal reduction section 92 attenuates or eliminates noise components from the synthesized sound signal generated by the sound output FM synthesizer section 6 . Specifically, as shown in FIG. 11, the signal intensity peak N1 to peak N4 in the noise band corresponding to the keynote KNOTE collated by the input keynote determination unit 91 are attenuated. Filtering by a notch filter, for example, can be employed to attenuate the signal intensity peak in the noise band.

Next, the operation of this embodiment will be described based on the flowchart shown in FIG.
The operation amount changing unit 753 of the signal strength estimation unit 75 reads the adjustment operation amount of each adjustment knob 32 of the adjustment operation unit 3 (step S1).
The test keynote output unit 751 of the signal strength estimation unit 75 outputs the test keynote TNOTE from the sound signal generation unit OP1′ to the sound signal generation unit OP4′ (procedure S2) to generate a synthesized sound signal (procedure S3).
The test keynote acquisition unit 81 acquires the test keynote TNOTE output from the test keynote output unit 751 (step S4).

The synthesized sound signal detection unit 752 detects the signal strength of the synthesized sound signal added by the input side adder 73B using the frequency corresponding to the test keynote TNOTE as the fundamental frequency (step S5).
The noise signal detection unit 82 detects the frequencies of the fundamental tone and overtones (frequency ratios other than integers) with the frequency corresponding to the test keynote TNOTE included in the synthesized sound signal detected by the synthesized sound signal detection unit 752 as the fundamental frequency. In the case of setting, the frequency of the fundamental tone and the overtone whose fundamental frequency is the frequency obtained by multiplying the frequency corresponding to the test keynote TNOTE by the frequency ratio), and the synthesized sound other than the frequency of the scale set by the different scale setting unit 84 A noise signal in the signal is detected (step S6).

The noise signal detection unit 82 determines whether or not noise signal detection has been completed for all test keynotes TNOTE (step S7).
If not, change the test keynote TNOTE and repeat step S2 and the subsequent steps.
When finished, the noise component accumulation unit 83 accumulates noise components for each test keynote TNOTE in the storage area (step S8).

The input keynote determination unit 91 compares the input keynote KNOTE output by the operator typing the MIDI keyboard 4 with the test keynote TNOTE accumulated by the noise component accumulation unit 83 (procedure S9). Next, the input keynote determination unit 91 reads peaks N1 to N4 of the signal intensity of the noise component corresponding to the input keynote KNOTE (step S10).
The noise signal reduction unit 92 attenuates or eliminates the signal strength peaks N1 to N4 in the noise band of the synthesized sound signal output from the sound output FM synthesizer unit 6 (step S11).
FM synthesizer 1 generates the fundamental tone and overtones with the frequency corresponding to the input keynote KNOTE as the fundamental frequency (if the frequency ratio is set to a value other than an integer, the frequency corresponding to the test keynote TNOTE is multiplied by the frequency ratio). fundamental tone and overtones with the frequency as the fundamental frequency) and a synthesized acoustic signal of the scale set by the different scale setting unit 84 are output, and voice is output (step S12).

According to this embodiment, the following effects are obtained.
In the present embodiment, the noise signal detection unit 82 detects the fundamental tone and overtones (if the frequency ratio is set to a value other than an integer, it is used for testing) with the frequency corresponding to the keynote KNOTE generated by the operation of the MIDI keyboard 4 by the operator as the fundamental frequency. The peak N1 to peak N4 of the signal strength of the noise signal other than the fundamental tone and overtones having the fundamental frequency obtained by multiplying the frequency corresponding to the keynote TNOTE by the frequency ratio are detected. Then, the noise signal reduction unit 92 attenuates or eliminates the signal strength peaks N1 to N4 of the detected noise signal. Therefore, the FM synthesizer 1 can output an acoustic signal of a scale corresponding to the keying position of the MIDI keyboard 4 by the operator, so that the acoustic signal output from the FM synthesizer 1, which is difficult to set, is not broken. , can output voice corresponding to the keynote KNOTE that you typed.

In this embodiment, the FM synthesizer 1 employs a noise signal detection section 82, a noise component storage section 83, an input keynote determination section 91, and a noise signal reduction section 92. FIG. In the case of the FM synthesizer 1, since the carrier wave generated by the oscillator 61 is modulated by the input modulating wave, the noise component does not occur in a specific frequency band, and the signal strength peak of the noise signal occurs at an arbitrary frequency. can occur. Therefore, the noise reduction section 9 of the present embodiment is suitable for the FM synthesizer 1 because it can attenuate or eliminate noise components even if they are noise components at arbitrary frequencies.

The present invention is not limited to the above-described embodiments, and includes modifications as described below.
Although the present invention is applied to the FM synthesizer 1 in the above-described embodiment, the present invention is not limited to this. That is, the noise reduction unit 9 may be applied to electronic musical instruments such as electronic pianos, electronic organs, electric guitars, and electronic woodwind instruments to attenuate and eliminate noise components.

In the above embodiment, the acoustic signal generator OP1 to the acoustic signal generator OP4 and the acoustic signal generator OP1' to the acoustic signal generator OP4' are configured by DSPs, but the present invention is not limited to this. . All configurations may be configured as a computer readable noise reduction program.
In addition, the present invention may be applied to other structures and configurations as long as the objects of the present invention can be achieved.

1 Multi-input 1 FM synthesizer 2 Synthesizer body 3 Adjustment operation unit 4 MIDI keyboard 5 Parameter selection unit 6 FM synthesizer for sound output 7 FM synthesizer for analysis 8 ... noise component analysis section 9 ... noise reduction section 31 ... case 61 ... oscillator 62 ... amplifier 62A ... output side amplifier 63 ... signal output section 63A ... output side amplifier 64 ... modulated wave input section 64A Input side amplifier 64B Input side adder 65 Acoustic signal synthesizing unit 66 Adder 67 Filter unit 70 Amplifier 71 Oscillator 72 Signal output unit 72A Output amplifier 73 Carrier signal input section 73A Input side amplifier 73B Input side adder 74 Adder 75 Signal strength estimation section 76 Limit amount notification section 81 Test keynote acquisition section 82 Noise Signal detection unit 83 Noise component accumulation unit 84 Heterogeneous scale setting unit 91 Input key note determination unit 92 Noise signal reduction unit 321 Main body 322 Adjustment position display marker 323 Base 324 Rotary shaft 325 Circuit board 326 Rotating resistor 327 LED light emitting unit 751 Test keynote output unit 752 Synthetic acoustic signal detection unit 753 Manipulated amount change unit 754 Limit amount determination unit , 755... selection unit, 761... control signal output unit, 762... notification state storage unit, KNOTE... key note, N1... peak, N4... peak, OP1... sound signal generation unit, OP2... sound signal generation unit, OP3... sound Signal generator, OP4... Acoustic signal generator, OP1'... Acoustic signal generator, OP2'... Acoustic signal generator, OP3'... Acoustic signal generator, OP4'... Acoustic signal generator, PO1... Output intensity pattern, PO2 ... output intensity pattern, PO4 ... output intensity pattern, PT1 ... pattern, PT2 ... pattern, PT3 ... pattern, PT4 ... pattern, TNOTE ... test keynote, W1 ... sine wave, W2 ... triangular wave, W3 ... sawtooth wave, W4 ... Square wave, f_in...Fundamental frequency, f_in'...Fundamental frequency.

Claims (4)

A performance device that outputs an acoustic signal of a scale corresponding to a keying position on a MIDI keyboard by an operator,
An FM synthesizer unit that generates a carrier wave having a frequency corresponding to a signal input from the MIDI keyboard in response to the operator's keystroke operation, modulates the generated carrier wave with a modulated wave having a predetermined frequency ratio, and generates an acoustic signal. When,
A component other than the fundamental tone of the fundamental frequency, which is the frequency obtained by multiplying the frequency corresponding to the signal input from the MIDI keyboard in response to the operator's keystroke operation by the predetermined frequency ratio, and a component other than the overtone of the fundamental tone as a noise component ; and
a noise signal reduction section that attenuates or eliminates the noise component detected by the noise signal detection section from the acoustic signal generated by the FM synthesizer section . The performance device according to claim 1,
A different scale setting unit that sets a frequency different from the fundamental frequency ,
The noise signal detection section excludes the frequency set by the different scale setting section from the detection target of the noise component . In the performance device according to claim 1 or claim 2,
A performance device in which the predetermined frequency ratio is adjusted by an adjustment knob operated by the operator . In the performance device according to any one of claims 1 to 3,
The FM synthesizer section has an oscillator that generates the carrier wave.

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