JPH03101798A - Musical sound signal generating device - Google Patents

Abstract

PURPOSE:To generate a musical sound which is close to that of a natural musical instrument by inputting a basic musical sound signal with a single or plural line spectra components and adding a noise signal whose band is limited almost to the respective spectrum components to the basic musical sound signal. CONSTITUTION:A noise component adding means 9 adds a noise signal to the basic musical sound signal S4. This noise signal S2 has its band limited almost to the line spectrum component of the basic musical sound signal S4, so the spectrum of the basic musical sound signal S4 is made irregular with the noise signal S2. Then the level of the basic musical sound signal S4 and the level and band width of the noise signal S2 are set properly. Consequently, the musical sound signal S5 outputted from the noise component adding means 9 is extremely close to the musical sound signal of the natural musical instrument.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a musical tone signal generating device suitable for use in a sound source such as an electronic musical instrument.

``Prior Art'' Conventionally, as a simple method for generating musical tones similar to those of natural instruments using electronic musical instruments, a basic musical tone signal generator that repeatedly outputs a basic musical tone signal of a predetermined waveform and a predetermined frequency, and It was possible to obtain a musical tone by using an envelope generator that outputs an envelope signal and multiplying the output signals of both.

However, the musical tones obtained by the above method do not have a sufficient natural musical instrument feel, and various techniques have been developed to solve this problem. One example of this is the method of adding fluctuations due to random noise to the envelope signal, thereby improving the natural instrument feel of musical sounds (Japanese Patent Publication No. 63-5655).
8). What these conventional methods have in common is that
The frequency components of musical tones are composed of multiple line spectra,
As a result, by controlling the line spectrum,
The goal was to bring musical sounds closer to natural sounds.

"Problem to be Solved by the Invention" However, although the above-mentioned method can produce musical sounds that are close to natural sounds to some extent, there are significant differences when compared with natural sounds, and they do not surpass the level of synthetic sounds. Ta. The reason for this is that the above-mentioned method focuses on controlling the line spectrum and does not give any consideration to controlling the line-to-line spectrum (noise).

On the other hand, according to the observations of the present inventors, it has been found that the line-to-line spectrum, which at first glance appears to be unnecessary noise, is an important element for imparting naturalness to musical sounds. For example, in a piano, when the strings are struck, the strings vibrate, and the soundboard resonates with the vibrations, producing sound. In reality, however, the casing also vibrates, producing noise. Furthermore, in instruments such as the flute, noise is generated due to the player's subtle breathing movements. These noises occur randomly near the line spectrum of musical tones, and needless to say, they are different from fluctuations in the envelope waveform. If these noises are not accurately reproduced, musical sounds will become unnatural.

The present invention has been made in view of the above-mentioned circumstances, and
It is an object of the present invention to provide a musical tone signal generating device capable of generating musical tones extremely close to those of natural musical instruments.

"Means for Solving the Problem" In order to solve the above problem, in the invention described in claim 1, a basic musical tone signal having single or plural line spectrum segments is used as a human input signal, and each line spectrum is The present invention is characterized by comprising noise component adding means for adding a band-limited noise signal near the component to the basic musical tone signal.

Further, in the invention as set forth in claim 2, in the musical tone signal generating device as set forth in claim 1,
The present invention is characterized by comprising a control means for controlling the noise component addition means so that the frequency spectrum of the noise signal automatically changes in accordance with the basic musical tone signal.

"Operation" In the invention described in claim 1, the noise component adding means adds a noise signal to the basic musical tone signal. Since this noise signal is band-limited to the vicinity of the line spectrum component of the basic musical tone signal, this noise signal imparts irregularity to the spectrum of the basic musical tone signal. By appropriately setting the level of the basic musical tone signal and the level and bandwidth of the noise signal, the musical tone signal output from the noise component adding means becomes extremely close to the musical tone signal of a natural musical instrument.

Further, in the invention described in claim 2, by automatically changing the frequency spectrum of the noise signal in correspondence with the basic musical tone signal, the musical tone signal output from the noise adding means is improved. This becomes even closer to the musical tone signal of a natural musical instrument.

"Example" Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the electrical structure of the first embodiment of the present invention.

In the figure, reference numeral 1 denotes a performance information generating device, which supplies performance information to the envelope generator 2. This performance information generating device l may be, for example, an electronic piano in which performance information is directly input from a keyboard, pedals, etc., or, for example, a floppy disk drive for reading out the contents of a floppy disk on which performance information is recorded. It may be a device. The envelope generator 2 generates an envelope signal S1 based on the supplied performance information, and outputs this to the adder 6.

The white noise generator 3 generates white noise S6 having a flat frequency spectrum as shown in FIG. 2(a), and supplies this to an LPF (low pass filter) 4. The LPF 4 has a passing characteristic as shown in characteristic A in FIG. 2 (portion), and thereby removes high frequency components from the supplied white noise and outputs it. A multiplier 5 multiplies the output signal of the LPF 4 by a DC signal 1 at a predetermined level, and outputs the result to an adder 6 as a noise signal St. As a result, the frequency spectrum of the noise signal S, becomes as shown by the characteristic A° in FIG. Further, by appropriately setting the level of the DC signal (2), the level of the noise signal (S) can be adjusted.

Adder 6 adds envelope signal S1 and noise signal S, and supplies added signal S3 to multiplier 9. Reference numeral 7 denotes a musical tone parameter information generating device, which stores musical tone parameters for reproducing various musical tones such as piano, harpsichord, flute, etc., and supplies one type of them to the basic musical tone signal generator 8. The basic musical tone signal generator 8 supplies a basic musical tone signal S4 having a waveform and cycle based on the supplied musical tone parameters to the multiplier 9. This basic musical tone signal S
The frequency spectrum of 4 is as shown in Figure 2 (2),
It is composed of a plurality of line spectrum segments W , , W , , W .

The multiplier 9 multiplies the basic musical tone signal S4 and the addition signal S, thereby outputting a musical tone signal S5.

The frequency spectrum of the noise component of this musical tone signal S is
This is shown in characteristic A'' in FIG. 2 (E).

That is, each line spectrum component W in (2) of the same figure,
, W, , W, and the frequency spectrum of these noise components is similar to the spectrum characteristic Δ' of the noise signal S in FIG.

Here, let W be the Fourier transform of the basic musical tone signal S4, N be the Fourier transform of the white noise, F be the passage characteristics of the LPF 4 and the volume 5, and express the Fourier transform P of the waveform of the musical tone signal S by a formula: P= W-N-F
...(1).

According to the above structure, when the cutoff frequency of the LPF 4 is adjusted and its passage characteristic is set as shown in the characteristic B of FIG. 2 (b), the spectrum of the noise signal St becomes the characteristic B of the same figure (c). The spectrum of the noise component in the musical tone signal S is as shown in characteristic B'' in FIG.

Similarly, if the level of the DC signal V, is lowered and the level of the noise signal S, is set as shown in the characteristic C of FIG. It becomes as shown in characteristic C'' in (e).

In this way, in this embodiment, the bandwidth for noise suppression can be set by adjusting the LPF 4, and the noise suppression level can be set by adjusting the DC signal V.

It goes without saying that the above structure can be modified in various ways, as shown in FIG. 3, for example.

In FIG. 3, multipliers 1l, 12 and adder 13 are used in place of adder 6 and multiplier 9 in FIG. 1, but their operations are the same as in FIG.

Next, a second embodiment of the present invention will be described.

FIG. 4 is a Bronnock diagram showing the configuration of a second embodiment of the present invention. In the drawings, parts corresponding to those in FIGS. 1 and 3 are designated by the same reference numerals, and their explanations will be omitted.

In the figure, the output information of the performance information generating device 1 is supplied to the basic musical tone signal generator 8, and the basic musical tone signal S4 is finely adjusted according to the performance information. Further, the output information of the musical tone parameter information generating device 7 is supplied to the mechanical bellow generator 2,
The envelope signal is finely adjusted according to the musical tone parameter information. FIG. 5(A) is a frequency spectrum diagram of the musical tone signal S outputted from the multiplier 9, and similarly to FIG. 2(E), the line spectrum components W 1 , W 2 , W
3 and a noise component D added thereto.

Incidentally, since line spectrum components vary in various ways depending on musical tone parameter information, musical scale, performance information, etc., adding a uniform noise component to them may actually impair the naturalness of musical tones. For example, Figure 5 (
In the frequency spectrum diagram (b), the pitches of the line spectrum components w4 to w9 are relatively narrow. When a noise component is added to these line spectrum components in the same way as characteristic D in FIG.

That is, the naturalness of musical tones may be impaired due to noise components being too noticeable.

In view of the above circumstances, a control circuit 10 is provided in this embodiment. That is, when performance information and musical tone parameter information are supplied to the control circuit 10, the control circuit 10 adjusts the O of the white noise generator 3 based on these information.
It performs N/OFF control, cutoff frequency control of LPF4, and level control of DC signal V1. For example, when the pitch of the line spectrum is narrow as shown in FIG. 5, the frequency spectrum of the noise component can be set as shown in characteristic F by lowering the cutoff frequency of the LPF 4. Thereby, the energy of the noise component can be reduced.

In addition, the method to lower the energy of noise components is LPF4.
It is not limited to lowering the cutoff frequency of the DC signal V, but the energy of the noise component may be lowered by lowering the level of the DC signal V. In some cases, the energy of the noise component may be lowered completely by turning off the white noise generator 3. Of course, noise components may also be removed. Also, LP
The KANOTO-OFF frequency of F4 or the level of the DC signal 1 may be varied randomly over time, or may be varied in accordance with the timing of key depression or key release included in the performance information.

As described above, according to this embodiment, the noise component can be automatically adjusted according to the performance information and musical tone parameters, so that it is possible to obtain a musical tone that is closer to that of a natural musical instrument.

"Effects of the Invention" As explained above, according to the present invention, it is possible to provide a musical tone signal generating device that can generate musical tones that are extremely similar to those of natural musical instruments.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the first embodiment of the present invention, and FIG. 2 (
A), (C), (2), and (E) are frequency spectrum diagrams of each signal in Fig. 1, the figure (opening) is a pass characteristic diagram of the low-pass filter 4, and Fig. 3 is a diagram of the first implementation. A block diagram of a modified example of the example, FIG. 4 is a block diagram of a second embodiment of the present invention,
FIG. 5 is a frequency spectrum diagram of the musical tone signal S in the embodiment. 3... White noise generator (noise component addition means), 4... Low pass filter (noise component addition means), 5.9... Multiplier (noise component addition means) means), 6...1... adder (noise component addition means), 1
0...Control circuit (control means).

Claims (2)

[Claims] (1) It is characterized by comprising a noise component adding means that receives a basic musical tone signal having one or more line spectral components as an input signal and adds a band-limited noise signal to the basic musical tone signal in the vicinity of each of the line spectral components. musical tone signal generator. (2) Claim 1, further comprising a control means for controlling the noise component addition means so that the frequency spectrum of the noise signal automatically changes in accordance with the basic musical tone signal. The musical tone signal generating device described above.