Electronic accordion, program

Abstract

To provide an electronic accordion capable of precisely simulating the playing method of an acoustic accordion.SOLUTION: The electronic accordion includes a pressure sensor for detecting a pressure in a bellows of the electronic accordion, a pressure change detection part for detecting a pressure change in the bellows based on a time change of a sensor value of the pressure sensor or a time change of a representation control signal which is a value based on the sensor value, an interpolation part for setting a shorter interpolation time as the detected pressure change is larger, and a sound level control part for adjusting a sound level at a predetermined time determined based on the sensor value or the representation control signal based on an average value of the sound level in a time section from the predetermined time to a time before the interpolation time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electronic accordion and a program. [Background technology]

[0002] For example, Non-Patent Document 1 is an example of prior art for electronic accordions. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Roland Corporation, "Keyboards, Keyboard Instruments, V-Accordion," [online], [Retrieved July 24, 2024], Internet <URL: https: / / www.roland.com / jp / categories / keyboards / v-accordion / > Summary of the Invention [Problem to be solved by the invention]

[0004] With conventional electronic accordions, the acoustic level of the musical notes can be unstable even when the player keeps the bellows moving at a constant speed, and expressiveness can be lost when the bellows are moved too quickly.

[0005] Therefore, the object of this disclosure is to provide an electronic accordion that can precisely simulate the playing technique of an acoustic accordion. [Means for solving the problem]

[0006] The electronic accordion of the present disclosure includes a pressure sensor, a pressure change detection unit, an interpolation unit, and a sound level control unit.

[0007] The pressure sensor detects the pressure inside the bellows of the electronic accordion. The pressure change detection unit detects the pressure change inside the bellows based on the time change in the sensor value of the pressure sensor or the time change in the expression control signal, which is a value based on the sensor value. The interpolation unit sets a shorter interpolation time the greater the detected pressure change. The sound level control unit adjusts the sound level at a predetermined time determined based on the sensor value or the expression control signal based on the average sound level within a time interval from the predetermined time to a time past the interpolation time. [Effects of the Invention]

[0008] The electronic accordion disclosed herein can precisely simulate the playing technique of an acoustic accordion. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the functional configuration of an electronic accordion according to a first embodiment. [Figure 2] 4 is a flowchart showing the operation of the sound generator of the electronic accordion according to the first embodiment. [Figure 3] 10A to 10C are diagrams showing examples of changes in the value of expression control signals in various playing styles. [Figure 4] 4 is a flowchart showing an interpolation time setting operation of the electronic accordion according to the first embodiment. [Figure 5] 10A and 10B are diagrams showing the correction of the sound level when the value of the expression control signal changes from the minimum value to zero. [Figure 6] FIG. 2 is a diagram showing an example of the functional configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail. Note that components having the same functions are assigned the same numbers, and redundant explanations will be omitted. [Example]

[0011] The functional configuration of the electronic accordion of Example 1 will be described below with reference to Fig. 1. As shown in the figure, the electronic accordion 1 of this example includes a waveform memory unit 51, an oscillator 52, an acoustic level control unit 53, a speaker 54, a bellows 100, a pressure sensor 10, an AD conversion circuit 11, a pressure change detection unit 12, and an interpolation unit 13. As shown in the figure, 51, 52, 53, and 54 are called a sound generator 5.

[0012] The signals and parameters used for the operation and control of each component are explained below (see also Figure 2).

[0013] <Waveform storage unit 51> The waveform storage unit 51 stores a waveform table (a group of multiple different waveforms) required for generating a continuous sound by the oscillator 52, and the like.

[0014] <Oscillator 52> The oscillator 52 generates an audio signal (S52) by successively reading sound samples from the wavetable and modifying the pitch and amplitude of the sound using the sound patch parameters. The oscillator 52 also modifies the audio signal based on a MIDI control signal received from the MIDI input.

[0015] <Expression control signal> The expression control signal, which is one of the main MIDI control signals that acts on the signal output from oscillator 52, will now be described.

[0016] The expression control signal is obtained by converting the pressure inside bellows 100 of electronic accordion 1 into an electrical analog signal (voltage signal) and then performing AD conversion on the converted value, in order to express the behavior of bellows 100.

[0017] The expression control signal is a MIDI control signal that changes the amplitude of the audio signal. Therefore, when the value of the expression control signal is high, the audio level of the audio signal increases, and when the value of the expression control signal is low, the audio level of the audio signal decreases. Also, when the value of the expression control signal is 0, the audio signal becomes silent. The expression control signal also affects the control of the sound filter, and is involved in controlling the timbre of the audio signal.

[0018] <Sound level control unit 53> The sound level control unit 53 adjusts the sound level at a predetermined time determined based on the expression control signal based on the average value of the sound level within a time period from the predetermined time to a time a predetermined time in the past (S53). The predetermined time is also called an interpolation time. The interpolation time will be described later. Note that the sound level control unit 53 may determine the sound level based on the expression control signal, or may determine the sound level based on the sensor value of a pressure sensor (described later) inside the bellows 100.

[0019] <Interpolation time> The interpolation time will be described below with reference to Figure 3. This figure is a graph showing an example of changes in the value of the expression control signal in response to changes in the performance of an electronic accordion. In the example shown in Figure 3, after an operation in which bellows 100 is slowly opened while maintaining a predetermined negative pressure (shown as "constant operation" in Figure 3), bellows 100 is quickly opened wide, and then an operation in which bellows 100 is repeatedly opened and closed at a slightly faster speed (shown as "high-speed transition" in Figure 3), and after an operation in which bellows 100 is slowly opened while maintaining a predetermined negative pressure (shown as "constant operation" in Figure 3), an operation in which bellows 100 is rapidly opened and closed again (shown as "bellows shaking" in Figure 3) is performed.

[0020] The interpolation time is set shorter the greater the change in pressure within a given time period, which is determined from the maximum and minimum values ​​of the pressure within bellows 100 within that given time period. Note that since the pressure and the expression control signal are corresponding values, the change in pressure corresponds to the change in the value of the expression control signal.

[0021] For example, in the operation situation shown as the first "constant movement," pressure changes are small, so the interpolation time p1 corresponding to this time interval is set long. For example, the sound level at a given time t1 is adjusted based on the average sound level within the time interval from the given time t1 to time t1-p1, an interpolation time p1 before. Because p1 is set to a long time in accordance with a situation in which pressure changes are small, pressure changes that occur during this time are smoothed by taking the average, making it possible to remove noise caused by small pressure changes. Note that a situation in which pressure changes are smoothed using such a long interpolation time is also referred to as "slow tracking" or "slow tracking speed," etc.

[0022] On the other hand, in an operation situation indicated as "fast transition," pressure changes are large, so the interpolation time p2 corresponding to this time interval is set short. For example, the sound level at a given time t2 is adjusted based on the average sound level within the time interval from the given time t2 to time t2-p2, which is the interpolation time p2 in the past. Because the interpolation time p2 is short, this average value is almost the same as the instantaneous value at the given time t2. Note that a situation in which pressure changes are smoothed by such a short interpolation time is also referred to as "fast tracking" or "fast tracking speed," etc.

[0023] In the operation situation shown as "bellows shaking" in the figure, the pressure change is so large that the corresponding interpolation time p3 may be approximately 0. In this case, almost no smoothing is performed using the interpolation time p3, and the instantaneous value at the specified time t3 is used almost directly as the sound level. This situation is also expressed as "fast tracking" or "fast tracking speed."

[0024] <Speaker 54> The speaker 54 reproduces the sound signal generated in step S52 and controlled in step S53 (S54).

[0025] <Bell 100> In an acoustic accordion, the volume of the musical sound is controlled by the pressure applied by the accordion player to the bellows. The higher the pressure applied to the bellows, the greater the flow of air passing through the reeds, and the louder the sound generated by the vibration of the reeds. The bellows of the accordion have very high expressiveness, and the accordion player can play both loud and soft sounds. Therefore, the acoustic accordion is a characteristic musical instrument with a very wide range of sound dynamics.

[0026] The electronic accordion 1 of this embodiment includes bellows 100 similar to those of an acoustic accordion, and the operation of the bellows 100 is accurately simulated by a pressure sensor 10 and the like, which will be described later.

[0027] Hereinafter, the operation for obtaining the interpolation time will be described with reference to FIG. 4.

[0028] <Pressure sensor 10> [[ID=ID=14]]The pressure sensor 10 is connected to the bellows 100 of the electronic accordion 1 and detects the pressure inside the bellows 100 (S10). The pressure sensor 10 converts the air pressure inside the bellows 100 into an electrical analog signal (voltage signal). The pressure sensor 10 measures the difference between the pressure inside the bellows 100 and the atmospheric pressure outside the bellows 100. Therefore, when the bellows are closed, the pressure sensor 10 measures a positive pressure, and when the bellows are open, the pressure sensor 10 measures a negative pressure. Using this sign information, it is possible to distinguish whether the bellows are open or closed. By removing the sign of the pressure, the absolute value of the pressure can be extracted. The absolute value of the pressure and the direction of the bellows are used to control the acoustic signal.

[0029] <AD conversion circuit 11> AD conversion circuit 11 converts the analog signal (voltage signal) that is the sensor value of pressure sensor 10 into a digital signal. This digital signal is a signal that represents the state of bellows 100. AD conversion circuit 11 converts this digital signal into an expression control signal (MIDI message) (S11). The expression control signal is sent to sound generator 5 and used to control the sound level. AD conversion circuit 11 also recognizes whether the bellows is open or closed based on the code information and sends this information (open / close information) to sound generator 5.

[0030] <Pressure change detection unit 12> Pressure change detection unit 12 detects pressure changes within bellows 100 based on the time change in the sensor value of pressure sensor 10 or the time change in the expression control signal, which is a value based on the sensor value (S12). For example, pressure change detection unit 12 may detect pressure changes by detecting all local minimum and maximum values ​​of the expression control signal and calculating the time between them. The magnitude of the pressure change represents how fast or slow the movement of bellows 100 is. Information about the pressure change is used to determine the optimal value of the interpolation time.

[0031] <Interpolation section 13> The interpolation unit 13 sets a shorter interpolation time as the detected pressure change is larger (S13). In other words, the interpolation unit 13 sets a longer interpolation time as the detected pressure change is smaller. As mentioned above, the interpolation time is an index that indicates how fast / slowly the sound amplitude should follow the amplitude changes requested by all amplitude controllers, such as the expression control signal.

[0032] If the interpolation time is short, the sound amplitude will follow too quickly and the sound level will tend to jump, which can make the output sound noisy.

[0033] On the other hand, if the interpolation time is long, the sound level will be uniform due to the smoothing effect mentioned above.However, if the interpolation time is too long, the output amplitude will not respond correctly to the performance when you want to suddenly change the musical tone due to accents or tremolo effects.

[0034] Therefore, when a constant output without any change is expected in the performance, it is preferable to set the interpolation time long so that the amplitude of the sound follows slowly, and to cut noise in the output sound by smoothing. On the other hand, when emphasis is placed on accents in the performance, it is necessary to set the interpolation time short so that the amplitude of the sound follows quickly.

[0035] For example, when an accordion is played at a very low volume, the value of the expression control signal is close to 0 (near air pressure), and even a slight change in the value of the expression control signal can cause a large change in output amplitude. For example, a change from 4 to 3 of the expression control signal results in a fluctuation of approximately 5 dB, a change from 3 to 2 results in a fluctuation of approximately 7 dB, and a change from 2 to 1 results in a fluctuation of approximately 12 dB. In such cases, slight movements of the bellows 100, sensor accuracy, noise contained in the analog signal, and errors in the conversion of the analog signal to a digital signal can all potentially result in noise. To reduce noise, it is necessary to set a long interpolation time so that the sound amplitude slowly follows transient changes in the value of the expression control signal (slow interpolation). In this case, the sound level adjustment using the interpolation time functions as a low-pass filter, resulting in a very stable, continuous change in the sound level.

[0036] Furthermore, for example, when the accordion is played while applying a constant pressure to the bellows 100, it is expected that the accordion will be played at a stable volume, so in this case too the interpolation time must be set long.

[0037] Also, for example, when an accordion player is playing with musical accents or using the bellows shake technique, the interpolation time must be set short in order to quickly follow pressure changes.

[0038] It is preferable that the interpolation unit 13 not only sets the maximum and minimum values ​​of the interpolation time, but also sets the value of the interpolation time continuously so that the best sound quality can be obtained regardless of the state of the bellows 100.

[0039] <Modification 1 (Correction when the value of the expression control signal changes from the minimum value to zero)> When the expression control signal is expressed in a small range, the gap between the minimum value of the expression control signal and zero becomes large, which can cause noise. For example, when the expression control signal is expressed as 8-bit information, the expression control signal is managed as a value between 0 and 128, but a large gap occurs in the acoustic level between the two values ​​of expression control signal value = 1 and expression control signal value = 0.

[0040] The interpolation unit 13 sets the interpolation time to the maximum value when the value of the expression control signal changes from the minimum value to zero. This makes it possible to smoothly transition from the sound level S1 to the sound level 0 when the expression control signal has a minimum value of 1, as shown in Fig. 5. This prevents the performance from sounding artificial, and allows the transition to a volume of 0 while maintaining a natural sound.

[0041] <Variation 2 (Simulation of Orchestral Instruments)> The electronic accordion 1 of this embodiment can also simulate instruments other than the accordion, such as string instruments in an orchestra.

[0042] For example, when simulating an orchestral instrument with the electronic accordion 1 of this embodiment, it would be musically unnatural for the reverberation sound to change depending on the movement of the bellows. For example, when the bellows 100 is reversed (open to closed, or closed to open), the value of the expression control signal becomes zero at the moment of reversal, and the sound level also becomes zero, but when simulating a stringed instrument, this reverberation may sound unnatural.

[0043] In this case, it is preferable that the electronic accordion 1 determines that a lingering sound has started when a predetermined time has passed since the value of the expression control signal became equal to or less than a predetermined threshold, samples the value of the expression control signal at the time the lingering sound started, and maintains the sound level based on the sampled value of the expression control signal from the start of the lingering sound until the value of the expression control signal remains at 0 for a predetermined time, thereby reproducing a natural lingering sound as the lingering sound of an orchestral instrument.

[0044] <Additional Notes> The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered to be circuitry or processing circuitry. A processor may also be a programmed processor that executes programs stored in memory.

[0045] In this specification, a circuitry, unit, or means is hardware that is programmed to realize or performs the described functions, which may be any hardware disclosed herein or any hardware known to be programmed to realize or perform the described functions.

[0046] If the hardware is a processor considered to be a type of circuitry, the circuitry, means, or unit is a combination of the hardware and software used to configure the hardware and / or processor.

[0047] The various processes described above can be implemented by loading a program that executes each step of the above method into the recording unit 10020 of the computer shown in Figure 6 and operating the control unit 10010, input unit 10030, output unit 10040, etc.

[0048] The program describing the processing contents can be recorded on a computer-readable recording medium, which may be, for example, a magnetic recording device, an optical disk, a magneto-optical recording medium, a semiconductor memory, or any other suitable recording medium.

[0049] The program may be distributed, for example, by selling, transferring, lending, etc. a portable recording medium such as a DVD or CD-ROM on which the program is recorded. Furthermore, the program may be stored in a storage device of a server computer, and then transferred from the server computer to another computer via a network, thereby distributing the program.

[0050] A computer that executes such a program may first temporarily store the program recorded on a portable recording medium or transferred from a server computer in its own storage device. Then, when executing a process, the computer reads the program stored on its own recording medium and executes the process in accordance with the read program. Alternatively, the computer may read the program directly from a portable recording medium and execute the process in accordance with the program. Furthermore, the computer may execute the process in accordance with the program each time a program is transferred from a server computer to the computer. The server computer may not transfer the program to the computer, but may instead execute the process through a so-called ASP (Application Service Provider) service, which realizes the processing function by issuing an execution instruction and obtaining the results. Furthermore, the server computer may execute the process on a terminal using a so-called SaaS (Software as a Service) service, which allows users to use part of the server computer along with the program. In this embodiment, the program includes information used for computer processing that is equivalent to a program (such as data that is not a direct instruction to the computer but has properties that define computer processing).

[0051] Furthermore, in this embodiment, the device is configured by executing a predetermined program on a computer, but at least a part of the processing contents may be realized by hardware.

Claims

1. a pressure sensor for detecting pressure within the bellows of the electronic accordion; a pressure change detection unit that detects a pressure change in the bellows based on a time change in a sensor value of the pressure sensor or a time change in an expression control signal that is a value based on the sensor value; an interpolation unit that sets a shorter interpolation time as the detected pressure change increases; a sound level control unit that adjusts a sound level at a predetermined time determined based on the sensor value or the expression control signal based on an average value of the sound level within a time interval from the predetermined time to a time past the interpolation time; Electronic accordion.

2. 2. The electronic accordion of claim 1, The interpolation unit When the value of the expression control signal varies from a minimum value toward zero, the interpolation time is set to a maximum value. Electronic accordion.

3. 2. The electronic accordion of claim 1, When a predetermined time has passed since the value of the expression control signal became equal to or less than a predetermined threshold, it is determined that a lingering sound has started, the value of the expression control signal at the time when the lingering sound started is sampled, and a sound level based on the sampled value of the expression control signal is maintained from the start of the lingering sound until the state in which the value of the expression control signal has become 0 continues for a predetermined time. Electronic accordion.

4. A program that causes a computer to function as the electronic accordion according to any one of claims 1 to 3.

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