JP2007047565A - Musical scale reader and sound generating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a musical score reading method in which a user can enjoy musical composition and a musical performance very inexpensively and easily by generating pseudo notes by himself or herself and reading them by an LED scanner. <P>SOLUTION: In a musical scale reader equipped with a plurality of light emitting diodes, a light emitting means of making the plurality of light emitting diodes emit light, and a photodetecting means of measuring quantities of photodetection of the plurality of light emitting diodes, the light emitting means irradiates a musical scale pattern image displaying a musical scale and the photodetecting means optically reads the musical scale pattern image out of the reflected light of a light emitted by the light emitting means and converts the musical scale pattern image into an electric signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a scale reading device using LEDs and a sound generation device that converts a sound signal output from the scale reading device into an acoustic signal and radiates the sound signal.

  In recent years, electronic musical instruments and the like for playing music have been remarkably developed, and musical instruments that can be automatically played are common. As a score reading method for performing an automatic performance, for example, a person plays a musical instrument having a recording / playback function, converts the performance into a digital signal, and records it on a medium such as a magnetic disk, a magnetic tape, an optical disk, There is a method of performing an automatic performance with this media. In addition, the music information represented by the score written on the musical score is analyzed by a person, and the analysis result is input to be converted into a digital signal and recorded on a medium such as a magnetic disk, magnetic tape, or optical disk. There is also known a method of performing an automatic performance using media.

Recently, a musical score image is created in advance, and the light source of the scanner is irradiated onto the musical score on which the image is displayed. The irradiated light is reflected on the musical score, and the reflected light is received and detected while moving the scanner on the musical score, thereby reading the image on the musical score. A reading method for analyzing musical tone information represented by a score read as an image and generating a musical tone is disclosed (see Patent Document 1).
JP-A-5-011752

  However, in the conventional score reading method, reading is performed by a scanner using a CCD element, image recognition processing is performed, and the result is taken into a PC (Personal Computer) and converted into an electronic score. There was a problem that the device was expensive.

  An object of the present invention is to create a musical note by yourself and read it with a plurality of LEDs, for example, an LED scanner, so that it is possible to enjoy composition and performance very inexpensively and easily. It is to realize a scale reading device by a reading method, and further to realize a sound generating device that converts a sound signal output from the scale reading device into an acoustic signal and emits it.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a plurality of light emitting diodes, a light emitting means for emitting light from the plurality of light emitting diodes, and a light receiving device for measuring the amount of light received by the plurality of light emitting diodes. In the scale reading device, the light emitting means irradiates a scale pattern image displaying a scale, and the light receiving means optically converts the scale pattern image from the reflected light of the light emitted from the light emitting means. It is characterized by being read and converted into an electrical signal.

  The invention according to claim 2 is a signal for generating a sound signal having a frequency corresponding to the read scale pattern image based on the electrical signal output from the light receiving means in the scale reading device according to claim 1. It further comprises a processing means.

  The invention according to claim 3 is the scale reading device according to claim 1 or 2, wherein the scale pattern image is composed of one or a plurality of scale dot images arranged in one direction at a predetermined interval. It is characterized by being.

  According to a fourth aspect of the present invention, in the scale reading device according to the third aspect, the scale dot image is composed of a dark color and a light color, and further comprises a determination means for determining the light and shade of the scale dot image. It is a feature.

  The invention according to claim 5 is the scale reading device according to claim 3 or 4, wherein the light emitting means and the light receiving means are arranged at a predetermined interval in the same direction as the arrangement direction of the scale dot images. It is characterized by that.

  According to a sixth aspect of the present invention, in the scale reading device according to the second aspect, the signal processing means includes an A / D converter that converts the electrical signal corresponding to each scale dot image into a digital bit signal; A scale code generation means for generating a scale code based on the converted digital bit signal, and a sound signal generation for generating a sound signal corresponding to the input scale code with reference to a frequency table associated with each scale code And a means.

  According to a seventh aspect of the present invention, there is provided the scale reading device according to any one of the first to sixth aspects, and an acoustic exchange unit that converts the sound signal output from the scale reading device into an acoustic signal and radiates the sound signal. It is characterized by having prepared.

  According to the present invention, it is easy to create a pseudo note, and a pseudo note of a song that the user likes can be created, so that composition and performance can be easily enjoyed. In addition, since a reading device including an LED scanner composed of a plurality of LEDs is very inexpensive, the cost can be greatly reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 shows a main configuration of a scale reading device 1 according to an embodiment of the present invention. As shown in the figure, the scale reading device 1 has a processing circuit 2 as signal processing means, a signal amplification circuit 3 composed of light emitting means and light receiving means, and includes five LEDs 1 to 5. The processing circuit 2 includes an A / D conversion unit 4, a determination processing unit 13, a bit processing unit 5, a data storage unit 6, a sound signal conversion processing unit 7, a sound signal output unit 8, an LED light emission control output unit 9, and the like. Composed. The sound signal conversion processing unit 7 and the sound signal output unit 8 operate as a sound generator.

  In the present embodiment, among the five LEDs 1 to 5, LED1, LED3, and LED5 are light emitting LEDs (light emitting means), and LED2 and LED4 are used as light receiving LEDs (light receiving means). The LED 1, LED 3, and LED 5 for light emission are controlled by the LED light emission control output unit 9. On the other hand, the LED 2 and / or the LED 4 receive reflected light by light emitted from the LED 1, LED 3, and LED 5 lit by the LED light emission control output unit 9 to the scale pattern image 11. LEDs 1 to 5 are light emitting diodes having a PN junction.

  Specifically, the LED light emission control output unit 9 is connected to the LED 1, LED 3, and LED 5 among the light emitting diodes LEDs 1 to 5, and executes control for lighting these LEDs. When the output of the LED light emission control output unit 9 is LO, a predetermined potential is supplied to the light emitting LEDs 1, LED 3, and LED 5, and a bias voltage is applied to the cathode side of the light emitting LEDs 1, 3, and 5. And LED1,3,5 to which the voltage was given emits light. When the output of the LED light emission control output unit 9 is HI, the light is turned off. When the light-receiving LED 2 having a PN junction is irradiated with reflected light reflected from the scale pattern image 11, a photovoltaic force is generated in a direction that biases the PN junction in the forward direction. In this case, if the open electromotive force is Vo, it is known that Vo = k (T / q) × In (I / Is). In this equation, Is is the saturation current in the reverse direction, k is the Boltzmann constant, T is the absolute temperature, q is the charge of the electrons, and I is the photocurrent.

  In order to generate photovoltaic power, light having a wavelength of λ = 1240 / Eg (nm) or less is required when the energy gap is Eg (ev). Therefore, for example, when a red LED sealed with a transparent member that emits light at a wavelength of λ = 660 (nm) is used as a light receiving element, it has light receiving sensitivity on the shorter wavelength side than 660 (nm), There is no sensitivity to wavelengths in the infrared region that are not shorter than 660 (nm). That is, the visibility correction filter required for the photodiode as the light receiving element is not necessary.

  When the open electromotive force generated by the LED 2 is Vo and the bias voltage is Vk, a voltage of Vo + Vk is applied as an input voltage to the gate 31a of the MOSFET 31 (described later). As a result, an output voltage is generated between the gate and source of the MOSFET 31. The same applies when the LED 4 is irradiated with reflected light.

  Here, the circuit configuration of the signal amplifier circuit 3 will be described. A signal amplifier circuit 3a is connected to the light receiving LED 4, and a signal amplifier circuit 3b is connected to the light receiving LED 2. Since the signal amplifier circuits 3a and 3b have the same configuration, description of the signal amplifier circuit 3b is omitted. A gate 31 a of a MOSFET (field effect transistor) 31 is connected to the anode side of the light receiving LED 4. Further, a load resistor 32 is connected to the drain 31b of the MOSFET 31, and a feedback resistor 33 is connected to the source 31c. Between the load resistor 32 and the MOSFET 31, there is a branch wiring 20 that branches to measure the light reception output received by the light receiving LED 4. The light reception output is output from the branch wiring 20 to the A / D converter 4. To do. Both MOSFET 31 and MOSFET 35 are enhancement type P-channel MOSFETs.

  The A / D conversion unit 4 is a conversion circuit unit that converts an analog signal into a digital signal. Specifically, an electrical signal corresponding to an image of each scale is converted into a digital bit signal. With the above-described processing, the MOSFET 31 and the MOSFET 35 can be made conductive, and when a voltage proportional to the input voltage is generated between the gate 31a and the source 31c of the MOSFET 31 and between the gate 35a and the source 35c of the MOSFET 35, currents are respectively supplied to the drain 31b and the drain 35b. Will occur. Since both the MOSFET 31 and the MOSFET 35 are enhancement type P-channel MOSFETs, when the voltage generated between the gate 31a and the source 31c of the MOSFET 31 and between the gate 35a and the source 35c of the MOSFET 35 increases, the current generated in the drain 31b and the drain 35b decreases. . Therefore, the voltage value output to the A / D converter 4 also decreases as the voltage generated between the gate 31a and source 31c of the MOSFET 31 and between the gate 35a and source 35c of the MOSFET 35 increases. Therefore, when the LED 2 and the LED 4 receive strong light, that is, when the reflected light reflected on the light-colored area is received, the voltage value output to the A / D conversion unit 4 becomes low, and the LED 2 and the LED 4 receive weak light. In other words, the voltage value output to the A / D conversion unit 4 increases when the reflected light reflected by the dark area is received. When the A / D conversion unit 4 converts the input voltage value into a digital bit signal, the A / D conversion unit 4 outputs the signal to the determination processing unit 13.

  When the digital bit signal is input, the determination processing unit 13 determines whether or not the bit value is higher than a preset threshold value, and outputs the determination result to the bit processing unit 5.

  The bit processing unit 5 performs an operation as a scale code generation unit that generates a scale code based on the determination result of the determination processing unit 13. Specifically, when the determination processing unit 13 determines that the digital bit signal converted by the A / D conversion unit 4 is lower than a preset threshold value, the bit processing unit reads the scale pattern image 11. It is determined that the irradiated area is light, and the bit value of the binary code is set to “0”. On the other hand, if it is higher than the preset threshold value, it is determined that the irradiated area of the scale pattern image 11 is dark, and the bit value of the binary code is set to “1”.

  For example, when the determination result by the determination processing unit 13 is input to the bit processing unit 5 by the above-described processing, the bit value based on the determination result is set to the 0th bit of the data byte. Next, when the LED 2 receives the reflected light from the light emission of the LED 3, the same processing is performed, and the bit processing unit 5 determines whether or not the input voltage value is higher than the threshold value, and the determination result is as follows. Set the bit value based on the first bit of the data byte. In this way, binary codes from 0 to 3 (hereinafter referred to as scale codes) are generated.

  The data storage unit 6 includes a recording medium (not shown) in which programs, data, and the like are stored in advance, and the recording medium is configured by a magnetic or optical recording medium or a semiconductor memory. This recording medium is fixedly provided in the data storage unit or is detachably mounted. Specifically, bit data in which the frequency of each scale is associated with a plurality of bit data set by the bit processing unit 5 is stored (see FIG. 3).

  The sound signal conversion processing unit 7 refers to the frequency table (see FIG. 3) associated with each scale code generated by the bit processing unit 5 and generates a sound signal corresponding to the input scale code. An operation as a generation unit is executed. Then, a sound is output from the speaker 10 at a frequency associated with the scale code.

  Next, FIG. 2 shows a tone scale pattern image (hereinafter referred to as image) 11 having light and shade, and a schematic diagram in which an LED is installed above, and a method of reading the light and shade pattern with the LED will be described.

  As shown in the figure, the LEDs 1 to 5 are arranged in a line at an equal distance. Then, a row of LEDs 1 to 5 are installed with a certain distance from the shade patterns of areas 1 to 4 arranged on the image 11. In the image 11, light colors are areas 2 and 4, and dark colors are areas 1 and 3. Among the LEDs 1 to 5, the light emitting LED and the light receiving LED are alternately arranged. Therefore, in the present embodiment, the LEDs 1, 3, and 5 are LEDs for light emission, and the LEDs 2 and 4 are LEDs for light reception, so that they are arranged as shown in FIG. Although the light emitting LED and the light receiving LED are alternately arranged, the present invention is not limited to this.

  The light emitted when the LED 1 is turned on is reflected by the area 1 of the image 11 and is incident on the LED 2 adjacent to the LED 1. At this time, since the area 1 is dark, the reflected light incident on the LED 2 is weak. On the other hand, the light emitted when the LED 3 is turned on enters the adjacent LED 2 and LED 4. First, the reflected light incident on the LED 2 is light reflected on the light-colored area 2, and thus the reflected light is strong. On the other hand, the reflected light incident on the LED 4 is light reflected by the dark area 3, and thus the reflected light is weak. The output voltages generated at the drains 31b and 35b of the MOSFETs 31 and 35 differ depending on the intensity of the incident reflected light. The bit processing unit 5 determines whether or not the output voltage is higher than a preset threshold value, determines the shading of the areas 1 to 4, and sets the bit value.

  Note that white and black, red and blue, and the like can be used for the shade patterns of the areas 1 to 4 of the image 11. For example, when a red LED is used, if the shading pattern of the image 11 is red and blue, red reflects red light strongly, and blue absorbs red light, so reflected light becomes weak.

  Next, FIG. 3A shows a table in which the scale code set by the bit processing unit 5 is assigned to a frequency corresponding to the scale, and FIG. 3B shows a scale pattern image of the scale “do”.

  As shown in the figure, the frequency of each scale is assigned in association with the scale code set by the bit processing unit 5. For example, when the scale code is “0001”, a frequency value 261.6 necessary for outputting a “do” sound is assigned.

  The shading pattern of the scale code “0001” has the configuration shown in FIG. The bit processor 5 sets a bit value at the 0th bit based on the data of the LED 2 that emits light to the area 1 where the LED 1 is light and receives the reflected light. Therefore, since area 1 is light color, the bit value of the 0th bit is “0” indicating light color.

  Next, the bit processing unit 5 sets a bit value to the first bit based on the data of the LED 2 that emits light to the light-colored area 2 and receives the reflected light. Accordingly, since area 2 is light color, the bit value of the first bit is “0” indicating light color.

  Similarly, the bit processing unit 5 sets a bit value to the second bit based on the data of the LED 4 that emits light to the light-colored area 3 and receives the reflected light. Since area 3 is light color, the bit value of the second bit is “0” indicating light color.

  The bit processing unit 5 sets a bit value at the third bit based on the data of the LED 4 that emits light in the dark area 4 and receives the reflected light. Since area 4 is dark, the bit value of the third bit is “1” indicating dark color. Therefore, the scale code corresponding to the shading pattern shown in FIG. 3B is “0001”. By assigning the frequency of the scale “do” to this scale code, the tone “do” is output from the speaker 10 when the density pattern “0001” is read.

  The same applies to the scale “Remifasolaside”. For example, “Le” has a scale code “0010”, so that it can be seen that area 3 is a dark and light pattern. Similarly, since “Mi” has the scale code “0011”, it can be seen that the areas 3 and 4 are dark and light patterns.

  As described above, a plurality of light emitting LEDs and light receiving LEDs are alternately arranged, and an image having an area composed of dark and light colors is irradiated by the light emitting LEDs. Based on the voltage value generated by the intensity of the reflected light received by the light receiving LED and the voltage value generated by the bias voltage via the signal amplifier circuit, it is determined whether the color is dark or light. Thus, by creating bit data and assigning and saving the frequency of each scale to each bit data, it is possible to play the scale by reading the tone pattern corresponding to the scale code. Since this scale code is assigned to each scale, the tone pattern is one pattern for each scale, so a large amount of data is not required and various tunes can be easily played by combining the tone patterns. Become. Further, the number of LEDs may be small, and not only can the cost be reduced, but the shape of the device can be simplified, and the scale reading device can be installed in a small space.

  Next, the tone pattern corresponding to the above-described bit data is shown in FIG. 4 for each scale, and the scale generation method will be described with reference to the scale code frequency assignment table of FIG.

  FIG. 4 shows a keyboard image 12 (hereinafter referred to as a “pseudo note”) in which a scale pattern image is composed of a plurality of scale dot images. Similarly to FIG. 3, area 1 corresponds to the 0th bit of bit data, area 2 corresponds to the 1st bit, area 3 corresponds to the 2nd bit, and area 4 corresponds to the 3rd bit. As described above, the bit processing unit 5 determines that the corresponding area is light color if the voltage value is lower than the preset threshold value, and sets the bit value to 0 and dark color if the voltage is higher than the threshold value. And the bit value is set to 1. Therefore, the scale code “0001” shown in FIG. 3 corresponds to “do” in FIG.

  As shown in the figure, the tone patterns of each scale are arranged in order like a keyboard, and LEDs 1 to 5 are installed on the pattern to generate each scale. Then, by moving on the pseudo note 12, the music is changed and the music is played. The LEDs 1 to 5 are installed at a predetermined interval in the same direction as the arrangement direction of the scale dot images.

  Further, in FIG. 4, scale stickers for creating scale dot images in the order of “Doremifasolaside” are pasted, but pseudo note 12 is created by arranging scale stickers in order of scale according to a certain tune, and LED 1 is placed on pseudo note 12. -5 can be installed and moved in a certain direction to play music. The movement of the LEDs 1 to 5 in one direction is not limited to this, and the pseudo note 12 may be moved. In addition, the speed of music can be changed by changing the moving speed, and quarter notes, bipart notes, etc. can be played by changing the interval of each scale seal.

  Next, processing executed by the scale reading device 1 will be described with reference to the flowchart of FIG.

  First, the LED light emission control output unit 9 starts control for LED1, LED3, and LED5. When the LED 1 is turned on and the LED 3 and the LED 5 are turned off (step S1), the LED 2 receives the reflected light from the area 1 of the image 11 irradiated by the LED 1 and is connected to the LED 2. Is output to the A / D converter 4. And the A / D conversion part 4 acquires a voltage (step S2).

  In step S <b> 2, when the A / D conversion unit 4 acquires the voltage, the A / D conversion unit 4 performs A / D conversion, and outputs the voltage value data converted into digital data to the bit processing unit 5. Then, when acquiring the voltage value data, the bit processing unit 5 determines whether or not the voltage value is higher than a preset voltage value. If the voltage value data is higher, the bit processing unit 5 determines that the area irradiated by the LED 1 is light and determines the bit value. Set to “0”. If the voltage value is lower than the preset voltage value, it is determined that the area irradiated by the LED 1 is dark and the bit value is set to “1”. This bit value is set to bit 0 (0th bit) (step S3).

  In step S3, when the bit value is set to the data byte bit 0, that is, the 0th bit, the LED light emission control output unit 9 next performs control to turn off LED1 and LED5 and turn on LED3 (step S4). ).

  In step S4, when LED1 and LED5 are turned off and LED3 is turned on, LED2 receives reflected light from area 2 of image 11 irradiated by LED3, and passes through a signal amplification circuit connected to LED2. The generated voltage is output to the A / D converter 4. And the A / D conversion part 4 acquires a voltage (step S5).

  In step S <b> 5, when the A / D conversion unit 4 acquires the voltage, the A / D conversion unit performs A / D conversion, and outputs the voltage value data converted into digital data to the bit processing unit 5. Then, when acquiring the voltage value data, the bit processing unit 5 determines whether or not the voltage value is higher than a preset voltage value, and sets the bit value to the data byte bit 1, that is, the first bit (step S6). ).

  In step S6, when data byte bit 1 is set, LED 4 receives the reflected light from area 3 of image 11 irradiated by LED 3 in the same manner, and the signal amplification circuit connected to LED 2 performs A / D conversion of the voltage. Output to unit 4. The A / D conversion unit 4 acquires a voltage (step S7).

  In step S <b> 7, when the A / D conversion unit 4 acquires the voltage, the A / D conversion unit 4 performs A / D conversion, and outputs the voltage value data converted into digital data to the bit processing unit 5. Then, when acquiring the voltage value data, the bit processing unit 5 determines whether or not the voltage value is higher than a preset voltage value, and sets the bit value to the data byte bit 2, that is, the second bit (step S8). ).

  When the data byte bit 2 is set in step S8, the LED light emission control output unit 9 next performs control to turn off the LEDs 1 and 3 and turn on the LEDs 5 (step S9).

  In step S9, when LED1 and LED3 are turned off and LED5 is turned on, LED4 receives the reflected light from area 4 of image 11 irradiated by LED5, and passes through a signal amplification circuit connected to LED2. The generated voltage is output to the A / D converter 4. And the A / D conversion part 4 acquires a voltage (step S10).

  In step S <b> 10, when the A / D conversion unit 4 acquires the voltage, the A / D conversion unit 4 performs A / D conversion, and outputs the voltage value data converted into digital data to the bit processing unit 5. Then, when acquiring the voltage value data, the bit processing unit 5 determines whether or not the voltage value is higher than a preset voltage value, and sets the bit value at the data byte bit 3, that is, the third bit (step S11). ).

  Next, a sound frequency is selected based on the bit data set and acquired in steps S3, S6, S8, and S11 and the data table (FIG. 3) (step S12). When the sound frequency is selected in step S12, Hi and Lo pulse oscillation control is performed by the frequency selected from the sound signal output unit 8, and the scale is output to the speaker 10 (step S13).

  As described above, a pseudo note (keyboard image) with a light and shade pattern can be easily created and a plurality of scales can be displayed on one image, so that the cost can be reduced and the data amount of one song can be reduced. , Problems such as data loss can be avoided. In addition, by adjusting the interval of each scale, the length of the sound can be changed, and by playing two-part notes and quarter notes, it is possible to perform using a wide range of musical pseudo notes It becomes.

  Further, by changing the moving speed of the reading unit composed of the light emitting LED and the light receiving LED, the speed of music can be changed, and the degree of freedom is improved.

  In the present embodiment, the scale pattern image is not limited to this and is configured to correspond to the binary code. Even when a scale sticker is affixed to the actual scale position on a 5-line score as in a normal score, reading can be performed by increasing the number of LEDs.

It is a figure which shows the principal part structure of the acoustic reader which concerns on this embodiment. It is a figure which shows the image 11 with a shading, and the schematic diagram which installed LED in the upper part. (A) is a figure which shows the table which assigned the scale code | cord | chord to the frequency corresponded to a scale, (b) is a figure which shows the scale pattern image corresponded to the scale code | cord | chord of scale "do". It is a figure which shows an example of the keyboard image which comprised the scale pattern image by the some scale dot image. It is a flowchart which shows the process performed with the scale reading apparatus which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scale reading apparatus 2 Processing circuit part 3, 3a, 3b Signal amplification circuit part
31, 35 MOSFET
32, 36 Load resistance 33, 37 Feedback resistance 31a, 35a Gate 31b, 35b Drain 31c, 35c Source 4 A / D conversion unit 5 Bit processing unit 6 Data storage unit 7 Sound signal conversion processing unit 8 Sound signal output unit 9 LED light emission Control output unit 10 Speaker 11 Scale pattern image 12 Keyboard image 13 Determination processing unit

Claims (7)

In a scale reading device comprising a plurality of light emitting diodes, light emitting means for emitting light from the plurality of light emitting diodes, and light receiving means for measuring the amount of light received by the plurality of light emitting diodes,
The light emitting means irradiates a scale pattern image displaying a scale,
The scale reading device characterized in that the light receiving means optically reads the scale pattern image from the reflected light of the light emitted from the light emitting means and converts it into an electrical signal.   The scale reading device according to claim 1, further comprising signal processing means for generating a sound signal having a frequency corresponding to the read scale pattern image based on an electrical signal output from the light receiving means. .   The scale reading device according to claim 1 or 2, wherein the scale pattern image is composed of one or a plurality of scale dot images arranged in one direction at a predetermined interval.   4. The scale reading apparatus according to claim 3, wherein the scale dot image is composed of a dark color and a light color, and further includes a determination unit that determines the light and shade of the scale dot image.   5. The scale reading device according to claim 3, wherein the light emitting unit and the light receiving unit are arranged at a predetermined interval in the same direction as the arrangement direction of the scale dot images. The signal processing means includes
An A / D converter for converting the electrical signal corresponding to each scale dot image into a digital bit signal;
Scale code generating means for generating a scale code based on the converted digital bit signal;
Sound signal generating means for generating a sound signal corresponding to an input scale code with reference to a frequency table associated with each scale code;
The scale reader according to claim 2, further comprising: The scale reading device according to any one of claims 1 to 6, and an acoustic exchange unit that converts a sound signal output from the scale reading device into an acoustic signal and radiates the sound signal;
A sound generator characterized by comprising:

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