JP2009251045A - Electronic musical instrument and sound quality control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correct musical sound outputted from an electronic musical instrument so as to be more audible. <P>SOLUTION: The sound quality control method includes: a step S51 of measuring noise around the electronic musical instrument when musical sound is not outputted from the electronic musical instrument; and a step S53 of correcting a frequency characteristic of the musical sound outputted from the electronic musical instrument so as to emphasize the sound in a frequency range having a large sound pressure level of the noise. The sound corrected in this way is audible in an environment where the noise occurs. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic musical instrument and a sound quality control method, and more particularly, to an electronic musical instrument that outputs an electrically generated musical sound and a sound quality control method used when changing the sound quality of the musical sound.

  2. Description of the Related Art An electronic musical instrument that outputs a musical sound generated in response to a player's operation is known. Furthermore, an electronic musical instrument that can output a musical sound with a changed sound quality is known. Such an electronic musical instrument is used in various environments, and the output musical sound may be difficult to hear due to noise in the environment. There is a demand for electronic musical instruments that output more easily audible music.

  In JP 2004-228937 A, the sound level is corrected for various noises by adjusting the volume according to the noise level for each frequency band according to various parameters (conditions), and An acoustic correction system is disclosed that provides optimal sound. The sound correction system includes a sound adjustment unit for correcting sound and a noise information detection unit for detecting noise information in the sound correction system in the in-vehicle audio apparatus, and the sound adjustment unit includes: The sound is corrected according to the level of noise detected by the noise information detecting means.

JP 2004-228937 A

  An object of the present invention is to provide an electronic musical instrument and a sound quality control method that make it easier to hear an output musical sound.

  In the following, means for solving the problems will be described using the reference numerals used in the best modes and embodiments for carrying out the invention in parentheses. This reference numeral is added to clarify the correspondence between the description of the claims and the description of the best mode for carrying out the invention / example, and is described in the claims. It should not be used to interpret the technical scope of the invention.

  The electronic musical instrument (1) according to the present invention includes a determination unit (3), measurement units (21, 22, 23, 24), and correction units (28, 30). The discriminating unit (3) discriminates whether or not a musical sound is output from the electronic musical instrument (1). Examples of the musical sound include those generated in response to the operation of the input device (11). The measurement unit (21, 22, 23, 24) measures noise around the electronic musical instrument (1) when the musical sound is not output. The correction unit (28, 30) changes the tone quality of the musical sound based on the noise. At this time, the electronic musical instrument (1) can change the tone quality of the musical sound so as not to be difficult to hear due to the noise.

  The measurement units (21, 22, 23, 24) measure the frequency characteristics of the noise. The correction unit (28, 30) changes the frequency characteristic of the musical sound based on the frequency characteristic of the noise. At this time, the electronic musical instrument (1) can change the frequency characteristic of the musical sound so as not to be difficult to hear due to the noise.

  The correction unit (28, 30) changes the frequency characteristic of the musical sound so that when the sound pressure level in the predetermined frequency band of the noise is higher than the predetermined level, the sound of the musical sound in the frequency band is emphasized. To do. At this time, the electronic musical instrument (1) can output the musical sound so as not to be difficult to hear due to the noise.

  The frequency characteristic of the noise indicates an average of a plurality of frequency characteristics measured intermittently. At this time, the electronic musical instrument (1) can prevent the frequency characteristic of the musical sound from changing suddenly and output a musical sound that is easier to hear.

  The electronic musical instrument (1) according to the present invention further includes an acoustic device detector that detects an acoustic device that outputs the musical sound. The correction units (28, 30) do not change the tone quality of the musical sound when the acoustic device is a predetermined acoustic device. At this time, the electronic musical instrument (1) can output a more appropriate musical sound when the influence of noise of the acoustic device that outputs the musical sound is small.

  The sound quality control method according to the present invention includes a step of determining whether a musical sound is output from the electronic musical instrument (1), and a step of measuring noise around the electronic musical instrument (1) when the musical sound is not output. (S51) and a step (S53) of changing the tone quality of the musical sound based on the noise. At this time, the sound quality control method can change the sound quality of the musical sound so as not to be difficult to hear due to the noise.

  The sound quality control method according to the present invention further includes a step of measuring the frequency characteristic of the noise and a step of changing the frequency characteristic of the musical sound based on the frequency characteristic of the noise. At this time, the sound quality control method can change the frequency characteristic of the musical sound so as not to be difficult to hear due to the noise.

  The frequency characteristic of the musical sound is changed such that when the sound pressure level in the predetermined frequency range of the noise is higher than the predetermined level, the sound in the frequency range of the musical sound is emphasized. At this time, the sound quality control method can output the musical sound so as not to be difficult to hear due to the noise.

  The frequency characteristic of the noise indicates an average of a plurality of frequency characteristics measured intermittently. At this time, the sound quality control method can prevent the frequency characteristic of the musical sound from changing abruptly and output a musical sound that is easier to hear.

  The sound quality control method according to the present invention further includes a step (S52) of detecting an acoustic device that outputs the musical sound. The tone quality of the musical sound is not changed when the acoustic device is a predetermined acoustic device. At this time, the sound quality control method can output a more appropriate musical sound when the influence of noise of the acoustic device that outputs the musical sound is small.

  The sound quality control program according to the present invention causes a computer to execute the sound quality control method according to the present invention.

  The electronic musical instrument and the sound quality control method according to the present invention can change the sound quality of the output musical sound so that it is not difficult to hear due to surrounding noise.

  An embodiment of an electronic musical instrument according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the electronic musical instrument 1 is connected via a bus 2 so that a plurality of electric circuits can bidirectionally transmit information to each other. The plurality of electric circuits include a CPU 3, a ROM 5, a RAM 6, an interface 7, a tone generator 8, and a digital signal processor 10.

  The CPU 3 executes a computer program installed in the electronic musical instrument 1 and controls the ROM 5, RAM 6, interface 7, tone generator 8, and digital signal processor 10. The ROM 5 records the computer program, and the RAM 6 temporarily records information generated by the CPU 3. The tone generator 8 is controlled by the CPU 3 to generate waveform data indicating a tone waveform.

  The interface 7 outputs information generated by an external device connected to the electronic musical instrument 1 to the CPU 3, and outputs information generated by the CPU 3 to the external device. The external device includes a keyboard 11, a panel 12, and a MIDI device 14. The keyboard 11 includes a plurality of keys used for performance. The plurality of keys are formed of a plurality of white keys and a plurality of black keys, and each correspond to a plurality of different pitches. The keyboard 11 outputs to the CPU 3 information identifying the key that has been pressed and its key strength. The panel 12 includes an input device, a display device, and an interface. The input device generates information when operated by the user, and outputs the information to the CPU 3. The display device displays an image generated by the CPU 3. The interface connects a headphone to the electronic musical instrument 1 and connects an external speaker to the electronic musical instrument. The interface further outputs the musical sound generated by the digital signal processor 10 when the headphones are connected to the electronic musical instrument 1, and the digital signal processor when the external speakers are connected to the electronic musical instrument 1. 10 is output from the external speaker. The MIDI device 14 records music data indicating a music and outputs the music data to the CPU 3 by a user operation. The music data directly indicates the timing at which each of the musical sounds constituting the music is generated. As the music data, a standard MIDI file (SMF) is exemplified.

  The digital signal processor 10 is controlled by the CPU 3 and generates a digital musical tone signal indicating a musical tone waveform based on the waveform data generated by the tone generator 8. The electronic musical instrument 1 further includes a microphone 15, an analog / digital converter 16, a digital / analog converter 17, an amplifier 18, and a speaker 19. The microphone 15 collects sound around the electronic musical instrument 1. The analog-digital converter 16 converts the sound collected by the microphone 15 into digital data, and outputs the digital data to the digital 10. The digital / analog converter 17 converts the digital musical tone signal generated by the digital signal processor 10 into an analog musical tone signal. The amplifier 18 amplifies the analog musical tone signal generated by the digital / analog converter 17. The speaker 19 is formed of one or a plurality of speakers, converts the analog tone signal amplified by the amplifier 18 into a tone, and emits the tone.

  FIG. 2 shows the digital signal processor 10. The digital signal processor 10 includes a fast Fourier transform unit 21, a loudness correction unit 22, a buffer unit 23, an average calculation unit 24, a line detection unit 25, a frequency characteristic correction unit 26, an addition unit 27, an inverse Fourier transform unit 28, and a headphone correction unit. 29 and a finite impulse response filter unit 30.

  The fast Fourier transform unit 21 performs fast Fourier transform on the sound collected periodically (for example, every second) by the microphone 15 to calculate the frequency characteristics of noise. The loudness correction unit 22 is controlled by the CPU 3 to correct the loudness of the frequency characteristics of noise calculated by the fast Fourier transform unit 21. The buffer unit 23 temporarily records the frequency characteristic corrected by the loudness correction unit 22. Further, the buffer unit 23 deletes the most frequently recorded frequency characteristic when a predetermined number (for example, 10) of frequency characteristics are recorded. The average calculation unit 24 averages the plurality of frequency characteristics recorded by the buffer unit 23.

  The line detection unit 25 detects whether an external speaker is connected to the panel 12. When an external speaker is connected to the panel 12, the frequency characteristic correction unit 26 generates a frequency characteristic of the external speaker. The frequency characteristic correction unit 26 generates the frequency characteristic of the speaker 19 when no external speaker is connected to the panel 12. The adding unit 27 calculates a frequency characteristic obtained by adding the frequency characteristic generated by the frequency characteristic correcting unit 26 to the frequency characteristic calculated by the average calculating unit 24. The inverse Fourier transform unit 28 performs inverse Fourier transform on the frequency characteristic calculated by the addition unit 27, and calculates a impulse response data string.

  The headphone correction unit 29 detects whether or not headphones are connected to the panel 12. The finite impulse response filter unit 30 performs a convolution operation on the waveform data generated by the tone generator 8 based on the impulse response data sequence calculated by the inverse Fourier transform unit 28 when no headphones are connected to the panel 12. And a digital musical tone signal is calculated. The finite impulse response filter unit 30 convolves the waveform data generated by the tone generator 8 without using the impulse response data sequence calculated by the inverse Fourier transform unit 28 when headphones are connected to the panel 12. Calculate and calculate a digital musical tone signal.

  FIG. 3 shows frequency characteristics of noise around the electronic musical instrument 1. The frequency characteristic 31 indicates that the level is large in a certain frequency range 32 and the level is small in another certain frequency range 33. At this time, the digital signal processor 10 changes the tone quality of the musical sound so that the level is high in the frequency range 32 and the level is low in the frequency range 33. The musical sound with the sound quality changed in this way is easy to hear in an environment where the noise is generated.

  The sound quality control method according to the embodiment of the present invention is executed by the electronic musical instrument 1 and includes a main routine, interval interrupt processing, and an operation for correcting the sound quality of a musical sound.

  FIG. 4 shows the main routine. The electronic musical instrument 1 is initialized when the power is turned on or when the reset switch of the panel 12 is pressed (step S1). In the initialization process, a plurality of electric circuits included in the electronic musical instrument 1 are initialized, and initial values are assigned to counters and flags. When the initialization process is completed, the electronic musical instrument 1 determines whether an event has occurred (step S2). The electronic musical instrument 1 executes event processing when an event occurs (step S3). The electronic musical instrument 1 executes non-event processing when no event occurs or when the event processing ends (step S4).

  FIG. 5 shows the event processing. When the key of the keyboard 11 is pressed or released (step S11, YES), the electronic musical instrument 1 executes key processing (step S12). When the panel 12 is operated (step S13, YES), the electronic musical instrument 1 executes an operation corresponding to the operation content (step S14). When an operation related to MIDI is performed (YES in step S15), the electronic musical instrument 1 executes an operation corresponding to the operation content (step S16). In the electronic musical instrument 1, the key of the keyboard 11 is not pressed or released (step S11, NO), the panel 12 is not operated (step S13, NO), and the MIDI operation is not performed (step S15, NO). ), Other processing is executed (step S17). Examples of the other processing include realizing a special operation that is executed when the switch of the panel 12 is pressed for a long time.

  FIG. 6 shows the key processing. When the key of the keyboard 11 is depressed (step S21, YES), the electronic musical instrument 1 determines whether or not the depressed key is the first depressed key (step S22). The first key depression indicates that any one of the plurality of keys is depressed in a state where all the plurality of keys included in the keyboard 11 are not depressed. The electronic musical instrument 1 substitutes ON for the flag FLG (step S23) when the key depression is the first key depression (step S22, YES). The electronic musical instrument 1 outputs a musical sound corresponding to the depressed key when the depressed key is not the first depressed key (step S22, NO) or after substituting ON for the flag FLG (step S24). ).

  When the key of the keyboard 11 is released (step S21, NO), the electronic musical instrument 1 determines whether or not the key release is the last key release (step S25). The last key release indicates that all keys of the keyboard 11 are released by the key release. When the key release is the last key release (step S25, YES), the electronic musical instrument 1 assigns 0 to the counter Tflg (step S26). After executing step S26 or when the key release is not the last key release (step S25, NO), the electronic musical instrument 1 performs a mute process on the musical tone corresponding to the key released (step S27). .

  FIG. 7 shows the non-event processing. The electronic musical instrument 1 calculates the magnitude relationship between the counter Tflg and the predetermined constant Tk (step S31). The constant Tk indicates the time from when all the keys on the keyboard 11 are released until the musical sound output from the electronic musical instrument 1 is muted. When the counter Tflg is equal to or greater than the constant Tk (step S31, YES), the electronic musical instrument 1 substitutes OFF for the flag FLG (step S32) and substitutes −1 for the counter Tflg (step S33).

  The electronic musical instrument 1 determines whether the flag FLG indicates ON or OFF after step S33 is executed or when the counter Tflg is smaller than a predetermined constant Tk (NO in step S31) (step S31). Step S34). When the flag FLG indicates OFF (step S34, YES), the electronic musical instrument 1 collects noise around the electronic musical instrument 1 using the microphone 15, and measures the frequency characteristics of the noise (step S35). ). Next, the electronic musical instrument 1 executes a process of adding predetermined effects and vibrato to the output musical sound (step S36).

  FIG. 8 shows the interval interrupt processing. The interval interrupt process is executed every 10 ms. The electronic musical instrument 1 calculates the sign of the counter Tflg (step S41). When the counter Tflg is negative (step S41, NO), the electronic musical instrument 1 increases the value indicated by the counter Tflg by 1 (step S42).

  According to the operations shown in FIGS. 4 to 8, the noise measurement in step S35 is executed when the electronic musical instrument 1 is not outputting a musical sound.

  FIG. 9 shows an operation for correcting the tone quality of the musical sound. The electronic musical instrument 1 calculates the average of the frequency characteristics of the noise using the latest 10 measurement results among the frequency characteristics of the noise measured in step S35 (step S51). The electronic musical instrument 1 determines whether or not the output musical sound is equalized (step S52). In other words, the electronic musical instrument 1 has a musical tone correction mode and a non-musical tone correction mode, and transitions to either the musical tone correction mode or the non-musical tone correction mode by the user operating the panel 12. When the electronic musical instrument 1 is in the musical tone correction mode and no headphones are connected to the panel 12 (step S52, YES), the musical instrument is equalized and corrected based on the average of the frequency characteristics (step S53).

  At this time, the electronic musical instrument 1 corrects the frequency characteristic of the output musical sound so that the sound in the frequency region where the sound pressure level of the noise is large is emphasized. That is, the musical tone is emphasized when the noise has a high level, and the low range is emphasized when the noise has a high level. Examples of the noise having a high level in the high sound range include a water work sound in a kitchen and a jet engine sound. An example of the noise having a high level in the low sound range is a sound at a construction site. That is, according to such an operation, the electronic musical instrument 1 can change the tone quality of the musical tone so that the user can easily hear each noise generated in the vicinity, and outputs the musical tone that is easy to hear in various environments. can do.

  In general, the way in which musical sounds output from headphones (earphones) are heard is not easily affected by environmental noise. According to such an operation, the electronic musical instrument 1 further allows the user to hear a more accurate musical tone without changing the tone quality of the musical tone when the user listens to the musical tone using the headphones. it can.

  Note that the electronic musical instrument 1 can be applied with another sound quality changing operation different from emphasizing the sound in the frequency range where the sound pressure level of the noise is large among the musical sounds. As the sound quality changing operation, changing the volume of the musical sound output from the electronic musical instrument 1 is exemplified.

FIG. 1 is a block diagram showing an embodiment of an electronic musical instrument according to the present invention. FIG. 2 is a block diagram illustrating a digital signal processor. FIG. 3 is a graph showing an example of noise frequency characteristics. FIG. 4 is a flowchart showing the main routine. FIG. 5 is a flowchart showing event processing. FIG. 6 is a flowchart showing key processing. FIG. 7 is a flowchart showing non-event processing. FIG. 8 is a flowchart showing interval interrupt processing. FIG. 9 is a flowchart showing an operation for correcting the tone quality of a musical sound.

Explanation of symbols

1: Electronic musical instrument 2: Bus 3: CPU
5: ROM
6: RAM
7: Interface 8: Tone generator 10: Digital signal processor 11: Keyboard 12: Panel 14: MIDI device 15: Microphone 16: Analog to digital converter 17: Digital to analog converter 18: Amplifier 19: Speaker 21: Fast Fourier transform unit 22: Loudness Correction unit 23: Buffer unit 24: Average calculation unit 25: Line detection unit 26: Frequency characteristic correction unit 27: Addition unit 28: Inverse Fourier transform unit 29: Headphone correction unit 30: Finite impulse response filter unit

Claims (11)

A discriminator for discriminating whether or not a musical sound is output from the electronic musical instrument;
A measurement unit for measuring noise around the electronic musical instrument when the musical sound is not output;
An electronic musical instrument comprising: a correction unit that changes the tone quality of the musical sound based on the noise. In claim 1,
The measurement unit measures frequency characteristics of the noise,
The electronic musical instrument that changes the frequency characteristic of the musical sound based on the frequency characteristic of the noise. In claim 2,
The electronic musical instrument changes the frequency characteristic of the musical sound so that the sound of the musical sound in the frequency band is emphasized when the sound pressure level of the noise in the predetermined frequency band is higher than a predetermined level. In claim 2,
The electronic musical instrument in which the frequency characteristic of the noise indicates an average of a plurality of frequency characteristics measured intermittently. In any one of Claims 1-3,
An audio device detection unit for detecting an audio device that outputs the musical sound;
The correction unit is an electronic musical instrument that does not change a sound quality of the musical sound when the acoustic device is a predetermined acoustic device. Determining whether a musical sound is being output from an electronic musical instrument;
Measuring noise around the electronic musical instrument when the musical sound is not output;
A sound quality control method comprising: changing a sound quality of the musical sound based on the noise. In claim 6,
Measuring frequency characteristics of the noise;
Changing the frequency characteristic of the musical sound based on the frequency characteristic of the noise. In claim 7,
The frequency characteristic of the musical sound is changed such that when the sound pressure level of the noise in a predetermined frequency range is higher than a predetermined level, the frequency band of the musical sound is emphasized. In claim 7,
The frequency characteristic of the noise indicates an average of a plurality of frequency characteristics measured intermittently. In any one of Claims 6-8,
Further comprising a step of detecting an acoustic device that outputs the musical sound,
The sound quality control method, wherein the sound quality of the musical sound is not changed when the sound device is a predetermined sound device. The sound quality control program for making a computer perform the sound quality control method in any one of Claims 6-10.

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