JP2001337680A - Method for generating wave form signals, wave form generator and storage media - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce processing loads in generating pseudo low tones by elec tronic musical instruments or the like. SOLUTION: The generator generates wave form data of ordinary tones 38 and wave form data of pseudo low tones 52 in advance, based on data 50 indicating the lowest frequency regeneratable by a speaker or the like and material wave form data 30. The wave form data of pseudo low tones 52 are generated by pitch or diapason lower than the lowest frequency and are reproduced with the wave form data of ordinary tones 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform signal generating method, a waveform signal generating device, and a recording medium used in a device for generating a musical tone signal, such as an electronic musical instrument, a mobile phone, an amusement device, and the like. The present invention relates to a waveform signal generation method, a waveform signal generation device, and a recording medium suitable for use in equipment.

[0002]

2. Description of the Related Art In an electronic musical instrument, a portable telephone, an amusement device, and the like, a musical tone signal is generated via a built-in or external electroacoustic transducer (such as a speaker). Here, the range of sound that can be converted has a predetermined limit. In particular,
With respect to low sounds, only sounds up to the lowest frequency defined by the lowest resonance frequency of the electroacoustic transducer (hereinafter, referred to as "lowest frequency" or "lowest reproducible frequency") can be produced.

[0003] In order to solve this, a technique for generating a "pseudo bass" is known. This is a technique using the illusion of a human being that when a sound signal having two frequencies is generated, a signal corresponding to the greatest common divisor of both is heard. For example, to generate a 100 Hz “pseudo bass” by a speaker that cannot output a 100 Hz audio signal, “200 Hz and 300 Hz” and “300 Hz and 40 Hz” are used.
It is preferable to generate two frequencies, such as "0 Hz", whose greatest common divisor is 100 Hz.

[0004] For example, US Pat. No. 5,930,373 discloses the details of the technology. In this technique, components that cannot be reproduced by a speaker in a digital audio signal sequentially supplied are subjected to a filtering process, and frequency components twice, three times,... Of these components are generated. The frequency component generated in this way and the original audio signal are added, and sound is generated via a speaker.

[0005]

However, in the technique of the above-mentioned U.S. Patent, it is necessary to perform a process such as a multiplication on a digital audio signal sequentially supplied at each sampling period, so that a pseudo bass is generated. A large amount of calculation is required to perform this. In electronic musical instruments and the like, it is necessary to perform various processes in addition to the generation of the pseudo bass, so that the processing capacity allocated for the generation of the pseudo bass is naturally limited. The present invention has been made in view of the above circumstances, and has as its object to provide a waveform signal generation method, a waveform signal generation device, and a recording medium that reduce the processing load required for generating pseudo bass.

[0006]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized by having the following constitution. Note that the contents in parentheses are examples. According to the configuration of the first aspect, in a waveform signal generating method for generating waveform signals of a plurality of sounding channels to generate a musical sound via an electroacoustic transducer, sounding instruction information (note) with a designated pitch is generated. Process of receiving on-event) (step SP2)
And a determining step (step SP8) of determining whether or not the designated pitch is equal to or less than a predetermined boundary pitch related to the electroacoustic transducer. If it is determined that the pitch is not lower than the boundary pitch, a first waveform signal generating step of generating a first waveform signal (steps SP10 and SP24) and A second waveform signal generating step of generating a second waveform signal that includes a plurality of overtones that are overtones of the designated pitch and that are not less than the boundary pitch, on condition that it is determined that the pitch is below the boundary pitch. (Step SP1
2, SP36, SP46). Further, in the configuration according to the second aspect, the first aspect
In the waveform signal generation method described above, the first waveform signal generation step is executed in the first sounding channel (steps SP24 and SP34) regardless of the determination result in the determination step, and the second waveform signal generation step is performed. Is executed in a second sounding channel different from the first sounding channel (step SP
36) outputting a waveform signal obtained by mixing the first waveform signal and the second waveform signal. Furthermore, in the configuration of claim 3, claim 1
In the waveform signal generation method described above, the first waveform signal generation step is to generate the first waveform signal by reading out first waveform data (normal tone waveform data 38) stored in advance. The second waveform signal generating step is for generating the second waveform signal by reading out second waveform data (pseudo low sound waveform data 52) stored in advance, and the designation is performed in the determining step. When it is determined that the pitch is equal to or lower than the boundary pitch, a waveform signal obtained by mixing the first waveform signal and the second waveform signal is output. Further, in the configuration according to a fourth aspect, in the waveform signal generation method according to the first aspect, the first waveform signal generation step (step SP24 in the second embodiment) includes the designated sound in the determination step. The second waveform signal is executed on condition that it is determined that the pitch is not lower than the boundary pitch, and the second waveform signal is a mixture of the first waveform signal and the waveform signal for pseudo bass generation. The signal is characterized by comprising: Further, in the configuration according to the fifth aspect, in the waveform signal generating method according to the first aspect, the first waveform signal generating step includes the step of generating the first waveform data (normal tone waveform data 38) stored in advance. To generate the first waveform signal by reading
In the waveform signal generation process, the second waveform data (pseudo low sound waveform data 52) which is stored in advance and is obtained by mixing the first waveform data (normal tone waveform data 38) and the waveform data for generating pseudo low tone is mixed. The second waveform signal is generated by reading. Furthermore, in the configuration according to claim 6, in the waveform signal generation method according to claim 1, the first and second waveform signal generation steps are each performed by the algorithm combining a plurality of operators. And generating a second waveform signal, wherein in the second waveform signal generating step, a plurality of circuits each having at least one operator are connected in parallel to generate a pseudo low sound waveform. I do. Furthermore, in the configuration according to claim 7, in the waveform signal generation method according to claim 6, the operator applied to the first waveform signal generation step is included in a first sound channel. The operator applied to the second waveform signal generation step is included in a second sound channel different from the first sound channel. Furthermore, in the configuration according to claim 8, in the waveform signal generation method according to claim 6, the operator applied to the first and second waveform signal generation steps is included in one sounding channel. And outputting a mixed waveform signal of the first waveform signal and the second waveform signal via the sounding channel. According to a ninth aspect of the present invention, the method according to any one of the first to eighth aspects is performed. According to a tenth aspect of the present invention, a program for executing the method according to any one of the first to eighth aspects is stored.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION First embodiment 1.1. Principle of Embodiment 1.1.1. Analysis of Waveform Components In the present embodiment, the musical tone waveform is stored separately as a “periodic component” and a “noise component”, and thus details thereof will be described. FFT sound waveform of natural musical instrument
When analyzed (Fast Fourier Transform), the frequency component of the musical sound waveform can be separated into a frequency component continuous on the time axis and a frequency component intermittent on the time axis. When the waveform is synthesized based on the former frequency component, a "periodic component" of a musical sound waveform is obtained, and when the waveform is synthesized based on the latter frequency component, a "noise component" of the musical sound waveform is obtained.

One example is shown in FIG. FIG. 7A shows a musical sound waveform (original waveform) of a saxophone. FIG. 4B shows the periodic component, and FIG. 4C shows the noise component. As can be seen from these figures, the interval where the noise component has a large amplitude level is short, and is often dispersed over a wider frequency range than the periodic component of the tone signal. For this reason, it is rare that the characteristics of the electro-acoustic transducer become a problem, and it is understood that it is sufficient to generate a pseudo bass only for the periodic component as needed.

1.1.2. Equal loudness curve In human hearing, even if the sound pressure level is constant, it seems that the sense of volume is different if the frequency is different. Therefore, when a curve of sound pressure level is drawn on the graph in which the horizontal axis is frequency and the vertical axis is sound pressure level, the loudness (loudness) becomes equal, as shown in FIGS. 5 (a) and 5 (b). Such characteristics are obtained. These characteristics are called "equal loudness curves". FIG. 2 (a) is called "Fletcher &Manson's equal loudness curve" and is slightly older. FIG. 2B is called "Robinson &Dadson's equal loudness curve", and is relatively new and adopted in ISO.

1.2. Hardware Configuration of Embodiment Next, a hardware configuration of a tone synthesis system according to a first embodiment of the present invention will be described with reference to FIG. Note that the hardware of the present embodiment is configured by a general-purpose personal computer. In FIG. 1, reference numeral 2 denotes a hard disk, which stores an operating system, an application program for a tone synthesis system, waveform data, and other various data. 4 is CD-ROM, D
It is a removable disk such as a VD-RAM, and stores the same information as the hard disk 2. 6 is a display,
Display various information to the user.

Reference numeral 8 denotes an input device, which includes a keyboard, a mouse, a keyboard, and the like, to which various information is input by a user. Reference numeral 10 denotes a sound board, which includes a waveform memory sound source that generates a tone signal based on the supplied performance information, and an AD converter that samples an analog signal input from the outside. A tone signal generated by a sound source in the sound board 10 is generated via the sound system 12. Note that the sound system 12 includes an amplifier and an electroacoustic transducer. As the electroacoustic transducer, a speaker, a headphone, or the like can be selected, and these have different conversion characteristics.

Reference numeral 16 denotes a MIDI interface for exchanging MIDI signals with an external MIDI device. Reference numeral 18 denotes a timer that generates an interrupt request at predetermined time intervals. Reference numeral 20 denotes a CPU, which controls each unit in the tone synthesis system via the bus 14 based on a control program described later. A ROM 22 stores an initial program loader and the like. Reference numeral 24 denotes a RAM, which is used as a work memory of the CPU 20.

1.3. Operation of Embodiment 1.3.1. Waveform data creation processing After the operating system has been started on the personal computer and the application program of the waveform analysis / synthesis system has been started, when the user performs a predetermined operation, the waveform data creation processing is executed. Details of the processing will be described with reference to FIG. The figure shows a CPU
FIG. 2 is a functional block diagram showing the contents of a processing program executed in the CPU 20.

In the figure, reference numeral 30 denotes material waveform data such as a recording waveform of a musical tone of a natural musical instrument, which is inputted from outside through the sound board 10 or the removable disk 4 or the like. Reference numeral 40 denotes a waveform analysis unit, which classifies the frequency components of the material waveform data 30 into components that are continuous on the time axis (deterministic frequency components) and other discrete components (noise components). Here, the waveform analyzer 40
Will be described with reference to FIG. Reference numeral 42 in the waveform analysis unit 40 denotes an FFT analysis processing unit which performs FFT analysis processing on the material waveform data 30. here,
First, for the material waveform data 30, the pitch period of 8
A double length window function is applied, and the frequency components within the window function are analyzed.

Next, the position of the window function is shifted backward by 1/8 of the pitch period on the time axis, and the frequency components are similarly analyzed. When this process is repeated for the entire original waveform data, a change in the frequency component on the time axis is obtained. Reference numeral 44 denotes a continuous component separation unit, which separates a continuous component on the time axis from a series of frequency components. The separated component is output as the deterministic frequency component 32 and is supplied to the synthesis unit 46. The synthesizing unit 46 synthesizes deterministic waveform data based on the deterministic frequency component 32. Reference numeral 48 denotes a subtraction unit that subtracts deterministic waveform data from the material waveform data 30. The result of this subtraction is output as noise component waveform data 34.

Referring back to FIG. 3, reference numeral 54 denotes attack & loop information, which is set by the user with reference to the material waveform data 30. Alternatively, it may be automatically set by using the result of the waveform analysis or the like in accordance with a user's designation. The contents of the attack & loop information 54 include the length of an attack portion that is read only once at the beginning of waveform reproduction, the length of a loop portion that is repeatedly read thereafter, and the like. Reference numeral 36 denotes a waveform synthesizing unit that synthesizes the waveform data of the attack unit and the loop unit based on the deterministic frequency component 32, the noise component waveform data 34, and the attack & loop information 54. The synthesized waveform data is usually stored in the hard disk 2 or the like as musical tone waveform data 38.

Here, an outline of the synthesizing process in the waveform synthesizing section 36 will be described. First, attack & loop information 5
4, the attack start address indicating the head of the attack part, the loop start address indicating the head and the end of the loop part, and the loop end address are determined.

Next, among the deterministic frequency components of the loop portion, a component having a value close to the phase of the loop start at the loop end is selected, and for the selected component, the phase at the loop end is different from the phase at the loop start. Corrected to match. When the loop is a long loop (loop size of several hundred milliseconds or more), a component (nonharmonic component) having a value that is not close to the phase of the loop start at the loop end may be selected and corrected. Next, sine wave synthesis is performed based on the corrected frequency component, and waveform data of the loop section is generated.

Next, among the deterministic frequency components of the attack part, components not used in the loop part are processed so as to gradually fade out from the middle of the attack part to the end of the attack part, and the processed decision is made. Sine wave synthesis is performed based on the theoretical frequency components, and waveform data of the attack portion is generated. Furthermore, noise component waveform data 3
This is mixed with the attack portion and the loop portion while controlling the volume of No. 4.

The waveform data of the attack portion and the loop portion created as described above has a waveform very similar to the material waveform data 30.
Also, the waveform data has a good connection from the loop end to the loop start.

Next, reference numeral 60 denotes a pseudo bass synthesizer, which generates pseudo bass sound data based on the lowest frequency data 50 indicating the lowest frequency of the sound system 12, the deterministic frequency component 32, and the attack & loop information 54. 52 is generated. Here, the lowest frequency data 50 may be one or a plurality of preset frequencies, or may be a frequency that can be arbitrarily set by a user with an operation element.
An extraction unit 67 in the pseudo bass synthesizer 60 extracts frequency components lower than the lowest frequency from the deterministic frequency components 32. Reference numeral 62 denotes a harmonic generation unit that generates a plurality of harmonic components exceeding the minimum frequency for each of the extracted frequency components. Here, the frequency of the extracted frequency component fluctuates with time, and accordingly, the frequency of the generated harmonic component fluctuates accordingly.

For example, if the lowest frequency is 120 Hz, 60 <f ≦ 120 Hz in the deterministic frequency component 32
Is generated at least twice and three times higher than the frequency component of Similarly, at least 3 times and 4 times higher harmonic components for the frequency components of 40 <f ≦ 60 Hz, and at least 4 times and 5 times higher harmonic components for the frequency components of 30 <f ≦ 40 Hz. Will be generated.

Next, reference numeral 68 denotes an envelope converter.
The envelope of each harmonic component is output so that the sense of loudness (loudness) of the pseudo bass generated by each harmonic component matches the sense of volume of the original frequency component. The contents will be described with reference to FIG. According to the equal loudness curves previously shown in FIGS. 5 (a) and 5 (b), the bass range (for example, 100H
It can be seen that in order to generate the same volume sensation in the harmonic components (for example, 200 Hz and 300 Hz) as in z), the level of the harmonic components must be reduced and the range of the level change must be increased.

Therefore, in the envelope conversion section 68, when the envelope level of the extracted original frequency component is as shown by the characteristic A in FIG. 7, this is converted into the characteristic B in FIG. And outputs it as the envelope level of the harmonic component. In the low sound range of the equal loudness curves in FIGS. 5A and 5B, the sound pressure level of the equal loudness decreases by 10 to 15 dB every time the frequency doubles. Therefore, the level L1 in FIG. 7 is set to “10 to 15 dB × multiplier”. Also, the magnitude of the change in sound pressure level at which the change in loudness becomes equal is about 1.4 times in “Fletcher & Manson” and 1 time in “Robinson & Dadson” every time the frequency is doubled. Approximately 1 time. Therefore, the level ratio L3 / L2 in the figure
Is set to about “1.1 to 1.4 × multiplier”.

Referring back to FIG. 3, reference numeral 64 denotes an amplitude controller, which controls each harmonic component output from the harmonic generator 62.
The envelope level output from the envelope conversion unit 68 is multiplied. Reference numeral 66 denotes a multiple waveform mixing unit that mixes each of the enveloped harmonic components. The result of this mixing is stored in the hard disk 2 as pseudo low sound waveform data 52.
Is stored in The normal musical sound waveform data 38 and the pseudo low sound waveform data 52 corresponding thereto are generated as described above.
When a user performs a predetermined operation, is transmitted to a waveform memory in the sound board 10 as waveform data of a user-defined tone color.

Generally, in a waveform memory sound source, different normal musical tone waveform data 38 is stored for each tone range of each tone color (waveform data may be shared between tone colors and tone ranges). In the present embodiment, of the normal musical sound waveform data, only the normal musical sound waveform data used for generating a musical tone with a fundamental component of the deterministic frequency component included in the pitch equal to or lower than the lowest frequency includes the corresponding pseudo low sound waveform data. 52 is stored in the waveform memory. Basically, it may be stored in a one-to-one correspondence with the normal musical sound waveform data 38, but this is not always necessary. In some cases, 1
A plurality of pseudo low sound waveform data may be stored for one normal musical sound waveform data, or one pseudo low sound waveform data may be stored correspondingly to a plurality of normal low sound waveform data. Normal musical sound waveform data 38 stored in the waveform memory
Is read out at a speed based on the F number when a tone signal is formed, so that a desired pitch is realized. Then, in the present embodiment, the sound system 12 out of the frequency components of the normal musical sound waveform data 38 is used.
The frequency component that is actually unreproducible due to the ability of
It will change according to the F number. Therefore, in the present embodiment, a plurality of types of pseudo low sound waveform data 52 are generated for each sound range.

For this reason, in the present embodiment, the range to which the one pseudo low sound waveform data 52 is applied is:
It is narrower than the range to which one normal musical sound waveform data 38 is applied, and the number of pseudo low sound waveform data 52 tends to increase. However, the memory area occupied by the pseudo low sound waveform data 52 can be made extremely small as compared with the normal musical sound waveform data 38 by suppressing the sampling frequency. The reason will be described.

First, the sampling frequency of the musical sound waveform is about 32 to 48 kHz in general consumer equipment, because the upper limit of the reproduction frequency is set to about 15 to 20 kHz. On the other hand, in the pseudo low sound waveform data 52, although the upper limit of the reproduction frequency is about 2 kHz (although it depends on the lowest frequency data 50), it is sufficient to secure the sampling frequency of about 5 to 10 kHz.
For this reason, the data amount of one pseudo low sound waveform data 52 is
It can be suppressed to a fraction of one to several tenths of one normal musical sound waveform data 38. When such a low sampling frequency is applied, it is preferable to employ high-precision interpolation between sample points such as "8-point interpolation".

1.3.2. After the waveform data is created as described above, when a MIDI event is input through the input device 8 or the MIDI interface 16, the sound board 1 is generated based on the MIDI event.
By controlling the waveform memory sound source within 0, a tone waveform is synthesized at the sound source. Also, the SMF (Standard MIDI) supplied via the removable disk 4 or the like is used.
Format) Even when a file is reproduced, a musical sound waveform is synthesized based on the event information. The content of the sound source control process will be described with reference to FIG.

(1) When the pseudo bass effect is off First, when a note-on event occurs, a note-on event processing routine shown in FIG. In the figure, when the process proceeds to step SP2, the part number is substituted for the variable PT, the note number is substituted for the variable NN, and the velocity is substituted for the variable VEL. Next, when the process proceeds to step SP4, it is determined whether or not the flag PLE is "1". Note that the flag PLE is a flag indicating the on / off state of the pseudo bass effect, and “1” indicates on and “0” indicates off. The value of the flag PLE can be switched at any time by performing a predetermined operation by the user.

If the flag PLE is "0", "N"
O "is determined, and the process proceeds to step SP10. Here, the normal sound generation control subroutine shown in FIG. 2B is called. In the figure, when the process proceeds to step SP22, a sound channel for one channel is assigned to the sound source in the sound board 10. The channel number of this assigned sounding channel is a1.

Next, when the process proceeds to step SP24,
For the channel number a1 in the sound source, the part number PT
Are set according to the tone color TC (PT), the note number NN, and the velocity VEL. Here, the tone parameters include the following.

(1) Tone TC (P) stored in the waveform memory
Of the plurality of normal tone waveform data 38 corresponding to T), the normal tone waveform data 38 corresponding to the note number NN
Address Information of (Selected Waveform Data) Normally, the musical tone waveform data 38 is composed of an attack portion and a loop portion, and therefore, it is necessary to set the start and end addresses thereof. However, the tone TC
Depending on the (PT), the normal tone waveform data 38 may be composed of only a loop portion or may be composed of only one-shot waveform data. Velocity V
In some cases, different waveform data is applied to each EL range.

(2) F number corresponding to note number NN In the normal musical tone waveform data 38, an original pitch OP is determined for each waveform data. When the note number NN is designated, the normal tone waveform data 3 is set according to the difference between the original pitch OP of the selected waveform data and the note number NN and the sampling frequency of the waveform data.
8, the F-number is determined.

(3) Volume Envelope Parameter When the timbre TC (PT), the velocity VEL, and the note number NN are specified, the volume envelope parameter for specifying the volume envelope is determined according to them. (4) Other parameters In addition, tone color TC (PT), note number NN, tone color filter parameter corresponding to velocity VEL, pitch modulation parameter, amplitude modulation parameter and the like are appropriately set.

Next, when the processing proceeds to step SP26,
Start of sound generation is instructed for channel number a1 of the sound source. Thus, the processing for the note-on event is completed. Thereafter, in the sound source of the sound board 10, the normal musical sound waveform data 38 is read out at a speed corresponding to the note number NN, and further subjected to a filtering process according to the tone color filter parameter and a volume control according to the volume envelope parameter. Time change processing is performed, and tone signals related to the channel number a1 are sequentially generated without including a pseudo bass. This tone signal is generated via the sound system 12. Even if the tone signal contains a frequency component lower than the lowest frequency, the component is not reproduced by the sound system 12, and the user cannot hear it.

(2) When the pseudo bass effect is on When the note-on event occurs when the pseudo bass effect is on (flag PLE = 1), the above steps SP2 and S
The process proceeds to step SP6 via P4. here,
Based on the tone color TC (PT) and the note number NN, it is determined whether or not a pseudo low sound waveform should be generated, that is, whether or not there is a low-frequency range component that cannot be reproduced in the sound system 12. Even if the note number NN is specified, the fundamental frequency may be shifted in octave units depending on the timbre, so that the timbre TC (PT)
Is determined in consideration of

For example, the lowest reproducible frequency is 120H
Let's assume a case where z is a note number corresponding to the fundamental frequency as it is (no octave shift). Here, if the reference pitch is A4 = 440 Hz, A
2 = 110 Hz, A # 2 = 116.54 Hz, B2 = 12
Since it is 3.471 Hz, it is understood that a pseudo low sound waveform should be generated when the pitch is A # 2 or less.

Next, when the processing proceeds to step SP8, the processing branches according to the result of the determination in step SP6. First, when it is determined that “a pseudo low sound waveform should not be generated (note number is B2 or more)”, the process proceeds to step SP1.
Go to 0. Thus, the normal sound generation control subroutine (FIG. 2B) is called in the same manner as when the pseudo bass effect is off. Accordingly, one tone generation channel is assigned to the note-on event, and a tone signal based on the normal tone waveform data 38 is sequentially generated in the tone generation channel.

On the other hand, "YES" in step SP8.
Is determined, the process proceeds to step SP12. Here, the pseudo bass sound generation control routine shown in FIG. 8 is called. In the figure, when the processing proceeds to step SP32, two sound channels are assigned to the sound sources in the sound board 10. Let the channel numbers of the assigned sounding channels be a1 and a2.

Next, when the process proceeds to step SP34,
For the channel number a1 in the sound source, the part number PT
Are set according to the tone color TC (PT), the note number NN, and the velocity VEL. The contents of the processing are the same as in step SP24 described above. Next, when the process proceeds to step SP36, a parameter for a pseudo bass is set in the channel number a2 corresponding to the tone signal generated in the channel number a1.

Here, there are the following tone parameters set for the pseudo bass. (1) Address information of pseudo low sound waveform data 52 (selected pseudo low sound waveform data) corresponding to the normal musical sound waveform data 38 selected in step SP34. (2) Pseudo low sound waveform data 52 corresponding to note number NN
F number. The F number for the pseudo low sound waveform data 52 is also determined in the same procedure as the F number of the normal musical sound waveform data 38.
That is, the original pitch OP of the pseudo low sound waveform data
And the note number and the sampling frequency of the pseudo low sound waveform data,
The number is determined. Here, the original pitch OP of the pseudo low sound waveform data has the same value as the original pitch OP of the corresponding normal musical sound waveform data (waveform data reproduced by the channel number a1). Therefore, the F number of the pseudo low sound waveform data normally has a predetermined proportional relationship with the F number of the musical sound waveform data (however, the sampling frequencies are different from each other). As a result, in the channel number a2, a pseudo bass sound in which the pitch and the time axis are completely synchronized with the tone signal generated by the channel number a1 is obtained.

(3) Volume Envelope of Pseudo Bass Corresponding to Volume Envelope of Channel Number a1 As described in FIG. 7, the volume envelope of the pseudo bass (characteristic B) is the same as the volume envelope of the original waveform (characteristic A). Is different. Therefore, the volume envelope for the pseudo bass is set by deforming the volume envelope of channel number a1. However, both the normal musical sound waveform data 38 and the pseudo low sound waveform data 52 store waveform data in which the volume envelope changes in the attack portion of the attack portion and the loop portion. Therefore, in each channel of the waveform memory sound source, it is not necessary to give a time-dependent change in the volume for the attack portion, and a volume envelope parameter for specifying a flat volume envelope of the attack portion is set. FIG. 9 shows a volume envelope (characteristic A ') for the normal musical sound waveform data 38 assigned by the channel number a1 and a volume envelope (characteristic B') for the pseudo low acoustic waveform data 52 assigned by the channel number a2. Here is an example.

Each volume envelope follows the relationship of equal loudness described with reference to FIG. 7, and starts changing when the waveform data reproduced in each channel enters the loop portion from the attack portion. In the flat part, the loudness of the frequency component lower than the lowest frequency included in the reproduced normal musical sound waveform data 38 substantially matches the loudness of the pseudo low sound waveform data, so that the level of the characteristic B ′ is higher than that of the characteristic A ′. It is set to be low. Further, in the loop portion, the loudness change amount of the component lower than the lowest frequency included in the loop portion of the normal tone waveform data to be reproduced substantially coincides with the loudness change amount of the loop portion of the pseudo low sound waveform data. Is set to be steeper than the slope of the characteristic A ′. Thereby, the channel number a2 is replaced with the channel number a.
As a result, a pseudo low acoustic waveform whose loudness characteristic follows a component having a frequency lower than the lowest frequency included in the tone signal generated in step 1 is obtained. (4) Other parameters The contents of other various parameters are basically set similarly to the channel number a1.

Returning to FIG. 8, when the process proceeds to step SP38, a sound generation start is instructed for the channel numbers a1 and a2 in the sound source. Thus, the processing for the note-on event is completed. After that, sound board 10
In the channel number a1 of the sound source, the note number NN
The normal tone waveform data 38 is read out at a speed corresponding to
A tone signal corresponding to the channel number a1 is sequentially generated without including the pseudo bass. In synchronization with this, the pseudo low sound waveform data 52 corresponding to the note number NN is read out at the channel number a2, and the pseudo low tone signal is sequentially generated. Thereby, both signals are emitted via the sound system 12. Although the sound system 12 does not reproduce a component having a frequency lower than the lowest frequency of the tone signal, the user can listen to the pseudo bass corresponding to the component instead of the non-reproduced component, and determine whether the component is being reproduced. Illusion.

As described above, according to the present embodiment, the volume envelope for the normal tone waveform and the volume envelope for the pseudo low tone waveform can be individually controlled, so that the volume is controlled according to the equal loudness curve according to the situation at each time. It is possible to control the level and the dynamic range.

2. Second Embodiment Next, a second embodiment of the present invention will be described. Although the hardware configuration of the second embodiment is the same as that of the first embodiment, the waveform data prepared in the waveform memory of the sound board 10 and the software configuration for control are slightly different from those of the first embodiment. Only the differences will be described.

(1) Waveform Data Creation Processing In this embodiment, the same waveform data creation processing as that described with reference to FIGS. 3 and 4 is executed, and the normal musical tone waveform data 38 and the pseudo low tone waveform data 52 are obtained. . Further, in the present embodiment, the processing shown in FIG. 10 is executed.

In the figure, reference numerals 72 and 74 denote amplitude control units for controlling the amplitudes of the waveform data 38 and 52. That is, the amplitudes of both waveform data are set such that a level difference corresponding to the difference between the attack portions of the characteristics A ′ and B ′ in FIG. 9 of the first embodiment is applied to the envelopes of both waveform data. Reference numeral 76 denotes a mixing unit which mixes both waveform data subjected to amplitude control, and outputs the result as pseudo low-tone waveform data 7.
Output as 8. These waveform data 38 and 78 are stored in the hard disk 2 and the waveform data 52 is deleted. In this manner, the normal musical sound waveform data 38 and the pseudo low sound waveform data 52 corresponding to the frequency components lower than the lowest frequency included therein, and the pseudo low sound waveform data amplitude-controlled to have the same loudness as the frequency components are obtained. The mixed low-pitched sound waveform data 78 was prepared.

Here, of the contents described with reference to FIG. 7, the sound pressure level is attenuated to make the loudness of the pseudo bass sound uniform, but the magnitude of the change in the sound pressure level is made to make the loudness change uniform. Has not gone. This is because "Robinson &Dadson" has determined that the ratio of the magnitude of the change in the sound pressure level is close to 1, and that it may be omitted. Created normal musical sound waveform data 3
8 and the corresponding pseudo bass sound waveform data 78
The data is transferred to a waveform memory in the sound board 10 according to a predetermined operation of the user. The waveform memory in the sound board 10 stores normal tone waveform data 38 for each tone range of each tone color.
The pseudo low tone waveform data may be prepared only for the normal tone waveform data 38 whose fundamental wave component is used at a pitch lower than the lowest frequency and used for tone generation, and stored in the waveform memory. .

(2) Note-On Event Processing In this embodiment, when a note-on event occurs, a note-on event processing routine shown in FIG. 2A is started, as in the first embodiment. The processing of step SP10 executed when the pseudo bass effect is off, or when the pseudo bass effect is on and there is no unreproducible bass frequency component in the generated tone signal is completely different from the first embodiment. Is the same. If the pseudo-bass effect is on and the generated tone signal contains a low-frequency component that cannot be reproduced, in step S12, instead of the processing of FIG. 8, the pseudo-bass sound generation control routine shown in FIG. 11 is called. It is.

Step SP4 executed in this routine
Steps SP2, SP44, and SP46 are the same as the contents of steps SP22, SP24, and SP26 (FIG. 2 (b)), which are respectively performed on the normal tone waveform. However, step SP44
In, the address information, the F number, the volume envelope parameter, and other parameters for the pseudo bass sound waveform data 78 are set for the sound source in the sound board 10 instead of the normal musical sound waveform data 38. The set address information is based on the tone color TC stored in the waveform memory.
Of the plurality of normal tone waveform data 38 corresponding to (PT), the normal tone waveform data 3 corresponding to the note number NN
8 is the address information of the pseudo low-pitched sound waveform data 78 corresponding to 8. The F number, volume envelope parameter, and other parameters may be basically set to the same values as the corresponding parameters of the normal tone waveform data 38.

Thus, in step SP46,
When the start of sound generation is instructed for the channel number a1 of the sound source, the sound source of the sound board 10 reads out the pseudo bass sound waveform data 78 at a speed corresponding to the note number NN. Filter processing according to the parameters and time-varying processing of the volume according to the above-mentioned volume envelope parameters are performed, and the tone signal related to the channel number a1 is sequentially generated in a state including the pseudo bass. This tone signal is generated via the sound system 12. Since this tone signal includes a pseudo bass corresponding to a frequency component below the lowest frequency that cannot be reproduced,
The user hears as if the frequency component is being reproduced.

According to this embodiment, even when a pseudo bass is generated, the number of sound channels assigned to one note-on event can be suppressed to one channel. Therefore, it is particularly suitable for use when it is desired to suppress an increase in the number of sounding channels.

3. Third Embodiment Next, a third embodiment of the present invention will be described. The hardware configuration of the third embodiment is the same as that of the first embodiment except that the sound source of the sound board 10 is not a waveform memory sound source but a frequency modulated sound source (FM sound source). Although the software configuration is slightly different from that of the first embodiment, only the differences will be described below.

(1) Waveform Data Creation Processing In this embodiment, since the tone signal is generated by the FM tone generator method, the waveform data creation processing as in the first and second embodiments is not executed.

(2) Normal tone generation control in note-on event processing In this embodiment, when a note-on event occurs, a note-on event processing routine shown in FIG. 2A is started as in the first embodiment. You. However, in the present embodiment, when the pseudo bass should not be generated, the normal sound generation control subroutine shown in FIG. 12A is called in step SP10.

In FIG. 12A, the processing is step SP5.
In step 2, the sound source in the sound board 10 is assigned a sound channel for one channel. The channel number of this assigned sounding channel is a1.

Next, when the processing proceeds to step SP54,
For the channel number a1 in the sound source, the part number PT
Are set according to the tone color TC (PT), the note number NN, and the velocity VEL. Generally, the tone parameters of the FM tone generator set for the tone generator channel are based on the tone data prepared for each tone color TC, and the note number NN and the basic tone parameter for the tone signal are used. It is prepared by adding a correction (scaling) according to the velocity VEL. Here, the tone parameters include the following.

(1) Algorithm In the FM tone generator system adopted in this embodiment, an algorithm (connection state of n operators) is selected according to the tone color TC (PT). Further, the type of waveform data used by each operator (sine wave, half-wave rectified sine wave, full-wave sine wave rectified waveform, etc.), and the progress speed of phase data for generating the waveform data are controlled. Pitch data (controls the pitch of waveform data), a multiplier for the pitch data for each operator (the progress speed of the phase data in each operator is controlled by the product of the multiplier and the pitch data), and low-frequency modulation control data (vibrato And the like, and the envelope parameters for controlling the envelope waveform applied to the waveform data generated by each operator include the tone color TC (PT) and the note number N.
N, which is determined according to the velocity VEL. As the contents of the algorithm, various kinds of contents can be considered as the contents of the algorithm. As a simple example, a case in which "n = 2" operators OP1 and OP2 are connected in series as shown in FIG. Can be

(2) Volume Envelope Parameter The volume envelope of the tone signal output from the FM sound source corresponds to the envelope assigned to the operator at the final stage of the above algorithm (OP2 in the example shown). As described above, the envelope parameters of the envelope are determined according to the tone color TC (PT), the note number NN, and the velocity VEL.

(3) Other Parameters When filtering the output of the algorithm, the timbre TC (PT), the note number NN,
A tone color filter parameter or the like corresponding to the velocity VEL is set. Further, a pitch envelope parameter for controlling a pitch envelope for changing the pitch of the generated tone signal may be set.

Next, when the processing proceeds to step SP56,
Start of sound generation is instructed for channel number a1 of the sound source. Thus, the processing for the note-on event is completed. Thereafter, the tone signal of the channel number a1 is sequentially generated in the sound source of the sound board 10 without including the pseudo bass. This tone signal is generated via the sound system 12. Even if the tone signal contains a frequency component lower than the lowest frequency, the component is not reproduced by the sound system 12, and the user cannot hear it.

(3) Pseudo Bass Sound Generation Control in Note-On Event Processing In the note-on event processing routine (FIG. 2 (a)), when the processing proceeds to step SP12, a pseudo bass sound generation control routine shown in FIG. 12 (b) Is called. When the process proceeds to step SP62 in the figure,
Two sounding channels are assigned to sound sources in the sound board 10. Let the channel numbers of the assigned sounding channels be a1 and a2.

Next, when the processing proceeds to step SP64,
For the channel number a1 in the sound source, the part number PT
Are set according to the tone color TC (PT), the note number NN, and the velocity VEL. The processing content is the same as that in step SP5 described above.
Same as 4. Next, when the process proceeds to step SP66, m operators for pseudo bass are reserved in the channel number a2 corresponding to the tone signal generated in the channel number a1, and these parameters are set.

Here, there are the following musical tone parameters set for the pseudo bass. (1) Algorithm In order to generate a pseudo bass, the channel number 2 contains OP
An algorithm (see FIG. 13B) having a configuration in which two operators 3 and OP4 are connected in parallel is set. The frequency components of the tone signal generated in channel number a1 include:
A frequency component corresponding to the note number NN that is not reproduced by the sound system 12 is included. Here, it is assumed that the operator at the last stage of the channel number a1 and whose multiplier of the pitch data is 1 generates the lowest tone of the channel. In that case, channel number a
For 2, the pitch data of the frequency f corresponding to the note number NN is set in the same manner as the channel number a1, and the operator of the channel number a2 sets the multiplier appropriately to generate the overtone of the frequency f. . In each operator, a combination of a plurality of multipliers (for example, “2,3”, “3,”) in which the pitch of the generated waveform data is larger than the lowest frequency and the greatest common divisor is “1”
4 ”,...) Are set, and the pitch frequencies of the actually generated signals are“ 2f, 3f ”,“ 3f, 4f ”,.

(2) Volume Envelope Parameter When the timbre TC (PT), the velocity VEL, and the note number NN are designated, the volume envelope assigned to the pseudo bass operator (OP3, OP4 in the illustrated example) is designated. For this purpose, a volume envelope parameter is determined. The relationship between the volume envelopes for both channel numbers a1 and a2 is the same as in the first and second embodiments.
That is, the envelope parameters of the volume envelope having an equal loudness relationship with the volume envelope of the unreproduced low-frequency component included in the tone signal generated on the channel a1 are set for the two operators of the channel number a2. Here, the envelope parameters set for each operator are different from each other according to the pitch of the generated waveform data.

(3) Other parameters Other parameters such as note number NN and tone color filter parameters corresponding to velocity VEL are set. When the pitch envelope is set to the channel number a1, the same pitch envelope is set to the channel number a2, so that the pitch of the pseudo bass generated by the channel number a2 is generated by the channel number a1. It is possible to follow the pitch fluctuation of the tone signal. Here, the tone parameters for the pseudo bass sound described above can be created in the same manner as the tone parameters for the tone signal. Specifically, first, each tone T
The data for the pseudo bass is included in the tone color data prepared for each C. Then, a correction (scaling) according to the note number NN and the velocity VEL is added to the basic tone parameter for the pseudo bass included in the tone color data, thereby creating a tone parameter for the pseudo bass.

Returning to FIG. 12 (b), the processing proceeds to step SP5.
At step 8, the sound generation start is instructed for the channel numbers a1 and a2 in the sound source. Thus, the processing for the note-on event is completed. Thereafter, in the channel number a1 of the sound source of the sound board 10, tone signals are sequentially generated without including a pseudo bass. In synchronization with this, note number N is assigned to channel number a2.
A pseudo bass signal corresponding to N is sequentially generated. When both signals are generated via the sound system 12, the channel number a1 is not reproduced even though the frequency component lower than the lowest frequency among the tone signals of the channel number a1 is not reproduced.
Due to the pseudo bass 2, the user has an illusion that the frequency component is audible.

4. Fourth Embodiment Next, a fourth embodiment of the present invention will be described. Although the hardware configuration of the fourth embodiment is the same as that of the third embodiment, the software configuration is slightly different from that of the third embodiment, so only the differences will be described.

(1) Sound Control with Pseudo Bass in Note-On Event Processing In this embodiment, when the processing proceeds to step SP12 in the note-on event processing routine (FIG. 2 (a)), it is shown in FIG. 12 (c). The sound control routine with pseudo bass is called. When the process proceeds to step SP72 in the figure, a sound source channel for one channel is assigned to the sound source in the sound board 10. The channel number of this assigned sounding channel is a1.

Next, when the process proceeds to step SP74,
An operator (m + n) is secured for the channel number a1 in the sound source. Here, in this embodiment, it is assumed that an FM sound source capable of changing the number of operators for each channel is used. “M” and “n” are the numbers of operators for normal sounding and pseudo bass in the third embodiment. Next, the tone color TC (PT) corresponding to the part number PT, the note number NN, and the velocity V
A tone parameter corresponding to EL is set.

The algorithm set here is equal to the algorithm of the third embodiment in which the algorithm for normal sound generation and the algorithm for pseudo bass are connected in parallel. One example is shown in FIG. Other settings of the tone parameters are the same as those in the third embodiment.

Next, when the processing proceeds to step SP76,
The start of sound generation is instructed for the channel number a1 in the sound source. Thus, the processing for the note-on event is completed. Thereafter, in the channel number a1 of the sound source of the sound board 10, tone signals including pseudo bass sounds are sequentially generated.

As described above, the difference between the third and fourth embodiments resides in that two or one sounding channels are secured when performing sound control with pseudo bass. Which embodiment to select may be determined based on whether the maximum number of operators per channel is “n + m” or more. In the example of FIG. 13, if the maximum number of operators is "3", the configuration of the third embodiment ((a) + (b) of FIG. 13) must be adopted. If the maximum number of operators is “4” or more, any of the embodiments can be adopted. However, the fourth embodiment is more advantageous in that the number of channels can be suppressed.

5. Modifications The present invention is not limited to the embodiments described above,
For example, various modifications are possible as follows. (1) In each of the above embodiments, the tone synthesis system is realized by software operating on a personal computer, but the same function is used for various electronic musical instruments, mobile phones, amusement devices, and other devices for generating tone. You may. Further, the software used in the above embodiment can be stored in a recording medium such as a CD-ROM or a floppy (registered trademark) disk and distributed, or can be distributed through a transmission path.

(2) In the above embodiment, a high-pass filter is inserted between the sound board 10 and the sound system 12 so as to attenuate a frequency component equal to or lower than the lowest frequency reproducible by the sound system. The following frequency components may be cut. Thereby, the power consumption of the amplifier in the sound system 12 can be reduced.

(3) If the sound board 10 is a PCM sound source having a waveform RAM, a pseudo low sound waveform may be generated by analyzing existing waveform data. At this time, the user may select or specify the lowest reproducible frequency, and automatically generate pseudo low sound waveform data based on the selected or specified lowest frequency.

(4) When the present invention is applied to an electronic musical instrument, when incorporating the present invention into an electronic musical instrument having a sound system, it is preferable that a quasi-bass effect matching the sound system be set in advance by the manufacturer. . Even in such a case, a plurality of settings may be prepared on the maker side so that the user can select a desired setting from the settings. on the other hand,
In the case of an electronic musical instrument (e.g., a synthesizer) or a sound board for a personal computer without a sound system, it is impossible to specify the sound system in advance. In this case, similarly to the above embodiment, the setting of the lowest frequency of the pseudo bass effect, the amount of attenuation, the amount of amplitude compression, and the like may be performed by a personal computer equipped with a panel of an electronic musical instrument or a sound board.

(5) In the above embodiment, the parameters for generating the pseudo bass sound include the lowest frequency, the amount of attenuation (level L1 in FIG. 7), and the amplitude compression amount of the pseudo bass sound (the level ratio in FIG. 7). L3 / L2). However, the amount of attenuation and the amount of amplitude compression may be fixed parameters, and the pseudo bass may be generated based only on the parameter of the lowest frequency. Alternatively, the pseudo bass may be generated based only on the attenuation and the lowest frequency without considering the change in the amplitude compression in the pseudo bass.

(6) In the above embodiment, when any one of a plurality of sound systems is used by switching, the lowest frequency and the like of each sound system are stored in advance, and the sound system to be used is switched. The pseudo bass effect may be automatically set according to the situation.

(7) The control data (pseudo bass control data) for controlling the pseudo bass may be included in a part of the tone color data of each tone. Further, the tone color data may include a plurality of pseudo bass control data corresponding to different lowest frequencies. In this case, if the lowest frequency of the sound system 12 is specified in advance by the user, the pseudo bass control data matching the lowest frequency can be automatically selected and used by simply selecting the tone. become.

(8) First and second waveform memory sound sources
In the embodiment, the analysis and creation processing of the waveform data stored in the waveform memory is performed, but the analysis and creation processing of the waveform data is not essential to the present invention. Waveform data (normal tone waveform data 38 and pseudo low tone waveform data 52) preliminarily analyzed and created is stored in a waveform memory, and the present invention can be implemented using the stored waveform data.

(9) In the third and fourth embodiments using the FM sound source, an algorithm in which two operators are connected in parallel to generate a pseudo bass is used, but other algorithms may be used. . For example, when using an algorithm in which two operators are connected in series, pitch data having the same pitch as the frequency of the low-frequency component that is not reproduced is set, and the operator on the modulator side uses a multiplier "1" to set a waveform having the same pitch as the frequency. Data may be generated, and the operator on the carrier side may generate the waveform data having a pitch twice as high as the frequency using the multiplier “2”. By applying frequency modulation to the double pitch waveform data with the same pitch waveform data, side band frequency components are generated at intervals of frequencies corresponding to the same pitch with the double pitch as the center. I do. A pseudo bass can be generated by using the carrier component of the double pitch and a sideband component one above (having a pitch three times the frequency of the low frequency component that is not reproduced).

In this case, the volume ratio between the carrier component and the immediately above sideband component is determined by the output level of the operator on the modulator side. For ease of control, it is preferable that the envelope of the operator on the modulator side is not fluctuated with time, that is, the volume ratio is set to a fixed value. As for the envelope of the carrier-side operator, the envelope parameter may be set so as to change with time while maintaining the relationship between the volume of the low-frequency component that is not reproduced and the equal loudness.

(10) In the above embodiment, the pseudo bass is generated by the waveform memory sound source or the FM sound source, but the sound source types are not limited to these two. For example, in the case of a sound source of a harmonic synthesis method or a partial sound synthesis method, a pseudo bass can be generated using one or more of a plurality of oscillators of each channel. In the case of a ring modulation type sound source, harmonics generated by ring modulation of two series of oscillators can be used for pseudo bass. If the sound source is capable of performing non-linear conversion of waveform data, a pseudo bass can be generated based on harmonics generated by the non-linear conversion. In addition, the present invention may be applied to a physical model sound source or an analog modeling sound source.

(11) In the above embodiment, the pseudo bass effect can be turned on / off, but it may be turned on all the time. (12) In the above embodiment, the user sets the lowest frequency, but data indicating the lowest frequency of each of a plurality of sound systems may be stored. Only by selecting the sound system to be used, the corresponding lowest frequency is automatically determined, and the pseudo bass effect corresponding to the lowest frequency can be automatically set.

[0088]

As described above, according to the present invention, it is possible to determine whether the designated pitch is equal to or less than a predetermined boundary pitch related to the electroacoustic transducer by determining whether the designated pitch is equal to or smaller than the first or second boundary pitch. Since the second waveform signal is generated, it is possible to generate a pseudo bass while reducing the required amount of calculation.

[Brief description of the drawings]

FIG. 1 is a hardware block diagram of a tone synthesis system according to a first embodiment of the present invention.

FIG. 2 (a) Note-on event processing routine and
6B is a flowchart of a normal sound generation control subroutine.

FIG. 3 is a block diagram showing the contents of a waveform data creation process in the first embodiment.

FIG. 4 is a block diagram showing the contents of a waveform data analysis process in the first embodiment.

FIG. 5 is a diagram showing an equal loudness curve.

FIG. 6 is a diagram showing a component analysis result of a waveform.

FIG. 7 is an envelope conversion characteristic diagram in the first embodiment.

FIG. 8 is a flowchart of a sound generation control routine with pseudo bass in the first embodiment.

FIG. 9 is a diagram illustrating an example of a volume envelope in the first embodiment.

FIG. 10 is a block diagram illustrating a main part of a waveform data creation process according to a second embodiment.

FIG. 11 is a flowchart of a sound generation control routine with pseudo bass in the second embodiment.

FIG. 12 is a flowchart of a control routine in the third and fourth embodiments.

FIG. 13 is a block diagram of an algorithm according to the third and fourth embodiments.

[Explanation of symbols]

2 ... Hard disk, 4 ... Removal disk, 6
... Display unit, 8 ... Input device, 10 ... Sound board, 12 ... Sound system, 14 ... Bus, 16 ...
... MIDI interface, 18 ... Timer, 20 ...
CPU, 22 ROM, 24 RAM, 30 material waveform data, 32 deterministic frequency components, 34
Noise component waveform data, 36... Waveform synthesis unit, 38.
Normal tone waveform data, 40: waveform analysis unit, 42: F
FT analysis processing unit, 44: continuous component separation unit, 46: synthesis unit, 48: subtraction unit, 50: lowest frequency data, 5
2... Pseudo low sound waveform data, 54... Attack and loop information, 60... Pseudo low tone synthesis unit, 62... Harmonic generation unit 64... Amplitude control unit 66.
7 ... Extractor, 68 ... Envelope converter, 72, 7
4... Amplitude control section, 76... Mixing section, 78... Pseudo low tone included waveform data.

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[Procedure amendment]

[Submission date] June 5, 2000 (2006.5.5)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

Claims (10)

[Claims] 1. A method for generating a waveform signal of a plurality of sounding channels for generating a musical tone via an electroacoustic transducer, comprising: receiving sounding instruction information with a designated pitch; A determining step of determining whether or not the pitch is equal to or less than a predetermined boundary pitch related to the electroacoustic transducer; and at least that the designated pitch is not equal to or less than the boundary pitch in the determining step. Is determined, a first waveform signal generating step of generating a first waveform signal, and a condition that it is determined in the determining step that the designated pitch is equal to or less than the boundary pitch is determined. A second waveform signal generating step of generating a second waveform signal including a plurality of overtones of the designated pitch and higher than the boundary pitch. 2. The method according to claim 1, wherein the step of generating the first waveform signal is performed in a first sound channel irrespective of a result of the determination in the step of determining. 2. The method according to claim 1, wherein the step is executed in a second sounding channel different from the first sounding channel, and outputs a waveform signal obtained by mixing the first waveform signal and the second waveform signal. The described method of generating a waveform signal. 3. The first waveform signal generating step includes generating the first waveform signal by reading out first waveform data stored in advance, and the second waveform signal generating step includes: Generating the second waveform signal by reading out the second waveform data stored in advance, and when it is determined in the determination step that the designated pitch is equal to or less than the boundary pitch, 2. The method according to claim 1, wherein the waveform signal generator outputs a waveform signal obtained by mixing the first waveform signal and the second waveform signal. 4. The first waveform signal generating step is executed on condition that it is determined in the determining step that the designated pitch is not less than or equal to the boundary pitch, and the second waveform signal generating step is performed. 2. The waveform signal generating method according to claim 1, wherein the waveform signal is a signal obtained by mixing the first waveform signal and a waveform signal for generating a pseudo bass sound. 5. The first waveform signal generating step includes generating the first waveform signal by reading out first waveform data stored in advance, and the second waveform signal generating step includes: Stored in advance in the first
2. The waveform signal according to claim 1, wherein the second waveform signal is generated by reading out second waveform data obtained by mixing the waveform data of (1) and waveform data for generating pseudo bass sound. Generation method. 6. The first and second waveform signal generating steps respectively generate the first and second waveform signals by an algorithm combining a plurality of operators, and the second waveform signal 2. A pseudo-low sound waveform is generated by connecting a plurality of circuits each having at least one operator in parallel in the generation process.
The described method of generating a waveform signal. 7. The operator applied to the first waveform signal generation step is included in a first sound channel, and the operator applied to the second waveform signal generation step is the first sound generation channel. 7. The waveform signal generating method according to claim 6, wherein the waveform signal is included in a second sounding channel different from the channel. 8. The operator applied to the first and second waveform signal generation processes is included in one sounding channel, whereby the first waveform signal and the second sound signal are transmitted through the sounding channel. 7. The waveform signal generation method according to claim 6, wherein a waveform signal obtained by mixing the two waveform signals is output. 9. A waveform signal generating apparatus for performing the method according to claim 1. Description: 10. A recording medium storing a program for executing the method according to claim 1. Description: