JPH0338697A - Stationary natural sound reproducing device - Google Patents

Abstract

PURPOSE:To eliminate level discontinuity between successive sound materials of a connection part and to reproduce an environmental sound equivalent to a natural sound by setting trapezoidal time windows for the sound materials to be connected and adjusting generation timing so that they cross each other at a specific attenuation level position. CONSTITUTION:A time window for the sound materials stored in a buffer A of a buffer memory part is set by a gate A of a gate part 3 and a time window for a sound material stored in a buffer B of the buffer memory part 2 is set by a gate B of the gate part 3. A control data generation part 4 has sound material selection data and continuance data as control data. Sound material data are read selectively out of a sound material memory 1 in order according to the sound material selection data and stored in the buffers A and B alternately and time windows which have a proper inclination and continuance are set by the two gates A and B of the gate 3 according to the continuance data to connect them in order, thus reproducing the environmental sound equivalent to the stationary natural sound.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is aimed at alleviating techno stress in offices, etc.
The present invention relates to a natural sound reproducing device used to create a relaxation space, and particularly to a steady natural sound reproducing device that connects and reproduces sound materials by adjusting the level.

[Conventional technology]

In general, the sounds that enter our living spaces include man-made sounds that are agglomerated from individual sounds such as people's voices and cars and can be heard as a background noise, and the sounds of brooks, wind, waves, etc. There are natural sounds such as the sounds of insects, chirps of insects, and chirping of birds, as well as artificially generated noises such as "environmental music" and BGM.
There are also things that make you lose concentration, and there are things that make you relax mentally, and the effects on your mental health vary depending on the environment and content.

Traditionally, in offices, etc., it has been used to relieve workers' tension, change their mood,
``Ambient music'' or BGM is used to improve efficiency. In addition, noise from ○A equipment in the office, conversations,
Stationary noise is used for the purpose of masking telephone noise, etc., and masking noise from neighboring residences in hotels, apartment complexes, etc.

That is, in indoor spaces, efforts have been made to create a space suitable for the purpose of use by blocking out noise from the outside and using sound absorbing materials to eliminate harmful internal echoes. However, simply blocking external noise or eliminating harmful echoes may not necessarily create an indoor space that meets the intended use, or may not create a comfortable space. Therefore, rather than muting the sound, BGM is actively used to mask external noise and improve work efficiency. However, since the melody of BGM is tied to a specific sensibility, it is difficult to expect a common effect for everyone, and people have their own likes and dislikes. There is also the problem of being distracted by the melody and unable to concentrate on work, so Uke is not consistently accepted by most people. Artificial stationary noise attempts to eliminate such melodies and reproduce meaningless sounds, but this has the problem that it eventually becomes perceived as noisy because there are few macroscopic fluctuations.

The phenomenon in which certain physical quantities such as amplitude, frequency, and timing of occurrence change over time is called ``fluctuation.'' This ``fluctuation'' is the reason why certain types of music and natural sounds have a relaxing effect on people. It is known that there is a deep relationship with In other words, natural sounds have irregularities,
For example, the sound of a babbling stream or the chirping of crickets have fluctuations in the volume, pitch, timing, etc. of the sound, and do not repeat frequently. One way to create environmental sounds that avoid the above-mentioned problems with BGM in recent years is to change the sense of volume to noise that does not have semantic information, that is, to change the sense of volume that humans are familiar with. Attempts are being made to provide some "fluctuation." 1, which widely exists in the natural world as "fluctuation characteristics",
It has been found that "amplitude fluctuation noise" which employs the /f characteristic, that is, "the property that the magnitude of fluctuation is inversely proportional to the frequency of fluctuation", is useful for improving the sound environment in a room or the like.

[Problem to be solved by the invention]

As mentioned above, in the case of "environmental music", as time passes, the musical elements, such as melody and rhythm, become more strongly conscious of the semantic information, so there are cases where it eventually becomes unpleasant and is no longer used. There are many. Furthermore, since "environmental music" is repeatedly played inside the shell via a physical medium such as a magnetic tape, humans can sense the cycle and often have the opposite effect.

Therefore, some "environmental music" is created in such a way that it does not emphasize the melody or rhythm as much as possible, but since it is created with a certain intention by humans, it is necessary to suppress the melody and rhythm, which are semantic information. has its own limits.

In addition, in the case of "natural sounds", since they do not have specific semantic information, they can be said to be suitable as a sound source for adding acoustics, so "natural sounds" are recorded in a natural environment. When using natural sounds as indoor environmental sounds, a method of repeatedly playing them is used, but it is difficult to record natural sounds under conditions suitable for sound environment control over a long period of time due to issues such as the continuity of natural phenomena. Moreover, considering the capacity of recording media such as magnetic tapes, if an attempt is made to cover the entire audio frequency band, the current limit is about two hours of recording. Therefore, when this time limit is exceeded, a method of repeatedly reproducing the same sound source is used. However, the human auditory system, including the cerebral processing system, has a hearing capacity of several hours.
Alternatively, since the player has the ability to detect the period on that side, there is a problem in that even if the playback is repeated for a long time, the player will eventually become conscious of a specific pattern and become uncomfortable.

In addition, the use of stationary noise that does not have semantic information has been considered as a way to compensate for the drawbacks of environmental music, but even if this stationary noise is played at a low volume, there are few macroscopic fluctuations, so As time goes on, it will eventually start to feel noisy. In other words, it has the disadvantage of being too monotonous.

Furthermore, "amplitude fluctuation noise" is monotonous because it does not include "fluctuations in pitch and timbre", that is, "frequency fluctuations", which are widely included in music, natural sounds, etc. This small process has the disadvantage of reducing the effectiveness of masking harmful sounds. In order to compensate for these limitations and shortcomings of "amplitude fluctuation noise", it can be said that it is effective to introduce the properties of "frequency fluctuation" in some way, but so far there are no effective and specific methods for this purpose. Not proposed.

The present invention solves the above-mentioned problems, and can easily create environmental sounds equivalent to natural sounds, and also does not create a sense of discomfort when connecting multiple stationary natural sound material data. It is an object of the present invention to provide a stationary natural sound reproducing device that reproduces stationary natural sounds by connecting the two devices in this manner.

[Means to solve the problem]

To this end, the present invention provides a steady natural sound reproduction device that stores a plurality of stationary natural sound material data of the same type and for a certain period of time, and sequentially connects and reproduces the sound materials by controlling the selected sound material data and duration. The present invention is characterized in that a trapezoidal time window is applied to the sound materials according to the duration, and the generation timing is adjusted so that the sound materials intersect at a predetermined attenuation level position, and the sound materials are connected and reproduced.

[Effect]

In the stationary natural sound reproduction I & placement of the present invention, a trapezoidal time window is applied to the connected sound materials and the generation timing is adjusted so that they intersect at a predetermined attenuation level position. No level discontinuity occurs. Therefore, it is possible to make the user feel as if two consecutive stationary sounds are being generated without causing any discomfort. Furthermore, since natural sound material data is used and concatenated with the sound material data while changing the duration, it is possible to reproduce environmental sounds equivalent to natural sounds.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a diagram showing the structure of one embodiment of the stationary natural sound reproducing device according to the present invention, FIG. 2 is a diagram showing an example of data and reproduction signals of the stationary natural sound generating device, and FIG. 3 is a diagram showing an example of the gate section. FIG. 3 is a diagram for explaining a time window and operation timing. 1, the sound material memo IJ1 stores a plurality of sound material data of the same type but different stationary natural sounds as shown in FIG. 2(a), for example. Buffer memo IJ gB2 consists of two buffer memo IJ A
%B, and the sound material data sequentially read from the sound material memory 1 are stored alternately. The gate section 3 consists of two games A and B, and has a buffer memory IJAS.
A time window (gate) having an appropriate slope and duration is applied to the sound material data of B, and the data are sequentially connected. The time window of the sound material stored in the buffer A of the buffer memory section 2 is multiplied by the gate 8 of the gate section 3, and the time window of the sound material stored in the buffer B of the buffer memory section 2 is multiplied by the gate B of the gate section 3. The control data generating section 4 has sound material selection data and duration data as shown in FIG. 2 ω) as control data.

Using this sound material selection data, sound material data are sequentially selected and read from the sound material memory 1 and stored in the buffer memo IJASB.
2 of the gate section 3 depending on the duration data.
A and B are sequentially connected by applying a time window with an appropriate slope and duration, and are reproduced as an environmental sound equivalent to a continuous, steady natural sound as shown in Figure 2 (C).

The control data generation section 4 uses the duration data generation section 8 and the duration control section 7 to select sound material data and to select the buffer memory section 2.
A trigger signal for reading out and controlling the gate section 3 is generated, and the selection data storage section 6 and the selection data control section 5 generate sound material selection data based on the trigger signal. The selection data storage section 6 and the duration data generation section 8 may store sound material selection data and duration data in chronological order in a table in accordance with the actual state of nature, or may store them using a random number generator. A device that generates these data may also be used.

As described above, in the steady natural sound reproduction device according to the present invention, a plurality of short-time (second order) sound materials of the same type are stored in the sound material memo IJl, and selection data with phonemes according to a certain algorithm is stored. , are played back sequentially according to duration data (occurrence timing data), but at this time the problem arises as to how to combine two consecutive pieces of data.In other words, how to combine two steady sounds In this case, if the images are combined as they are without any special processing, level discontinuity will occur, which will inevitably cause some sense of discomfort to humans.

Therefore, in the present invention, the sound material data stored in the buffer memory is multiplied by a trapezoidal time window (gate) as shown in FIG. By adjusting the generation timing so that they intersect at a 3 dB position, and by fading in and out, level fluctuations are eliminated when the sound materials are connected, and the auditory sense is that one continuous steady sound is occurring. Processing is being carried out to That is, when two sounds of the same level (L dB) that are uncorrelated with each other are synthesized, the level of the synthesized sound will be (L+3) dB. Therefore, the stationary part is set as OdB, and by combining at -3 dB from there, the resulting combined part is set as OdB.

Note that the duration is the time from one 3 dB point at the rising edge to one 3 dB point at the falling edge.

Note that the generation timing is adjusted so that the sound materials with two time windows intersect at a position of 13 dB, but the front end of this time window is changed in a fixed relationship with the duration, or it is changed randomly. Furthermore, the same sound material can be reproduced in different sections. In other words, by changing not only the duration but also the start-up position each time, it is possible to increase the randomness even with the same sound material.

Next, the procedure for reproducing regular natural sounds will be briefly explained.

■ Read out the 1st and 2nd selection data with phoneme from the selection data storage section 6, send it to the sound material memory 1, select the sound material data from the sound material memory 1, and read the sound material data from the sound material memory 1 to the buffer A (1st) of the buffer memory section 2; Send to buffer B (second).

(2) Output the sound material data of buffer A through gate 8 with a time length corresponding to the first duration data.

■ At the timing when the falling edge of the output signal of gate A and the rising edge of the output signal of gate B intersect at a level of 13 dB, the length corresponds to the second duration data)
The sound material data of buffer B is output via buffer B.

(2) After outputting the sound material data stored in buffer 8, sound material data is selected from sound material memory 1 according to the third selection data with phoneme and sent to buffer A.

■ At the timing when the fall of the output signal of B and the rise of the output signal to the gate intersect at a level of 13 dB, the sound of buffer A is transmitted through gate A whose length corresponds to the third duration data. Output material data.

(2) After outputting the sound material data stored in buffer B, the sound material data is selected from sound material memory 1 according to the fourth selection data with phoneme and sent to buffer B.

■ Repeat the steps from ■ to ■ below.

By the way, natural sounds can be broadly divided into the following two types.

■ Intermittent natural sounds that occur alone and intermittently, such as the chirping of crickets and other insects, the chirping of birds, the sound of large waves, the cry of a frog, etc. ■ Regular natural sounds that occur on a regular basis For example, the sound of a babbling stream, the sound of insects chirping in groups, the sound of the sea,
Sounds of Rain, etc. Figure 4 shows, as an example, changes over time in the level of natural environmental sounds recorded on a plateau in Aso National Park in Kumamoto Prefecture. Among these sounds, the sounds that occur intermittently at a relatively high level are the sounds of crickets chirping alone, while the sounds that occur regularly at a low level are the chirps of crickets chirping in groups. This includes sounds caused by the rustling of plants and trees caused by the wind.

Therefore, by mixing not only the stationary natural sounds generated by the stationary natural sound reproduction device of the present invention but also intermittent natural sounds, it is possible to create more natural environmental sounds.

FIG. 5 is a diagram showing an example of the configuration of a system in which a steady natural sound reproducing device and an intermittent natural sound reproducing device according to the present invention are combined, and FIG. 6 is a diagram showing an example of data and reproduction signals of an intermittent natural sound generating section. be.

In FIG. 5, the intermittent natural sound generating section 11 independently reproduces environmental sounds that are perceptually equivalent to intermittent natural sounds. The stationary natural sound generating section 12 uses the stationary natural sound reproducing device according to the present invention explained in FIG. 11, and reproduces an environmental sound that is audibly equivalent to the stationary natural sound. The synthesis unit 17 generates intermittent environmental sounds that are reproduced by the intermittent natural sound generation unit 11 and adjusted to have sound quality and appropriate level balance by the sound quality adjuster 13 and volume adjuster 14, and the intermittent environmental sounds that are reproduced by the steady natural sound generation unit 12 and adjusted to have sound quality and appropriate level balance. The sound quality and constant environmental sound adjusted to an appropriate level balance are mixed by the adjuster 15 and the volume adjuster 16 and output.

The intermittent natural sound generation unit 11 stores a plurality of sound material data of the same type but different intermittent natural sounds as shown in FIG. ) sound material selection data and generation timing data (i1 duration data) in accordance with the actual state of nature.
is included in the control data generation section 21. Then, the sound material memory 22 uses the sound material selection data of the control data generating section 21.
The sound material data is sequentially selected and stored in the read buffer memory 23, and the sound material data stored in the buffer memory 23 is read out at a timing that conforms to the actual state of nature based on the generation timing data, as shown in FIG. 6(C). It is played intermittently as an environmental sound equivalent to natural sound.

By synthesizing and outputting the intermittent environmental sound and the steady environmental sound respectively reproduced by the intermittent natural sound generating section 11 and the steady natural sound generating section 12 as described above, it is possible to combine and output the intermittent environmental sound and the stationary environmental sound, which are respectively reproduced by the intermittent natural sound generating section 11 and the steady natural sound generating section 12. Using natural sound materials, it is possible to create environmental sounds that are aurally equivalent to natural sounds and do not repeat over an extremely long period of time. In other words, by dividing natural sounds into two groups as described above, reproducing and synthesizing the natural sounds of each group according to the actual state of nature, intermittent sounds and steady sounds as shown in Figure 4 can be created. This creates environmental sounds that are aurally equivalent to the mixed natural environmental sounds.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiment, the structure is shown as having one intermittent natural sound generating section and one steady natural sound generating section. It may also be possible to control the combination.

It is equipped with a plurality of intermittent natural sound generators, and selects one or more of the intermittent natural sounds such as the chirping of crickets and other insects, the chirping of birds, the sound of large waves, and the cry of a single frog, as exemplified in (■) above. In addition, it is equipped with multiple stationary natural sound generators, and can generate stationary natural sounds such as the sound of a babbling stream, the sounds of insects chirping in groups, the sound of the sea, and the sound of rain. It may be possible to select a plurality of items and play them. In this way, for example, by selecting the sound of a babbling stream in the constant natural sound generating section and selecting the chirping of insects and the chirping of birds in the intermittent natural sound generating section, an environmental sound equivalent to the natural environmental sound in the mountains can be created. By selecting the sounds of insects chirping in groups in the constant natural sound generation part and selecting several insect cries in the intermittent natural sound generation part, it is possible to create an environmental sound equivalent to the natural environmental sound of a grassland. Furthermore, by selecting the sound of sea noise in the constant natural sound generation section and selecting the cries of several seabirds in the intermittent natural sound generation section, it is possible to create an environmental sound equivalent to the natural environmental sound of the seaside. can be created.

Furthermore, if the system is configured so that several combinations of intermittent natural sounds and steady natural sounds can be selected and output on multiple channels, natural environmental sounds can be independently and freely selected in each space.

Furthermore, in offices, etc., programs can be created depending on the time of day, such as changing the natural environmental sounds played during work hours and break times, or playing only regular natural environmental sounds during working hours. may be configured.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, environmental sounds are reproduced using sound material data obtained from natural sounds, so the characteristics of natural sounds can be utilized in the reproduced environmental sounds. It is possible to easily reproduce environmental sounds equivalent to . Moreover, since multiple pieces of sound material data are selected in sequence at random and connected and played by changing the duration and start position, it is possible to reproduce stationary environmental sounds equivalent to natural sounds that do not repeat with a small amount of sound material data. I can do it. Also,
By applying a trapezoidal time window to the connected sound materials, the generation timing is adjusted so that they intersect at a predetermined attenuation level.
Level discontinuity does not occur between the sound materials before and after the connection part.

Therefore, it is possible to make the user feel as if one continuous steady sound is being generated without causing any discomfort.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the structure of one embodiment of the stationary natural sound reproducing device according to the present invention, FIG. 2 is a diagram showing an example of data and reproduction signals of the stationary natural sound generating device, and FIG. 3 is a diagram showing an example of the gate section. Figure 4 is a diagram for explaining the time window and operation timing, and Figure 4 is a diagram showing temporal changes in the level of natural environmental sounds recorded as an example on a plateau in Aso National Park in Kumamoto Prefecture. Figure 5 is a diagram for explaining the time window and operation timing. FIG. 6 is a diagram showing an example of the configuration of a system in which such a stationary natural sound reproducing device is combined with an intermittent natural sound reproducing device, and FIG. 6 is a diagram showing an example of data and reproduction signals of an intermittent natural sound generating section. 1... Sound material memory, 2... Buffer memory section, 3
...Gate section, 4...Control data generation section, 5...
Selection data control section, 6... Selection data storage section, 7...
- Continuation time control section, 8... Continuation time data generation section. Figure 2 (α) (b) Example of control data (an example of constant natural sound playback Figure 3<b) Time

Claims (4)

[Claims] (1) A stationary natural sound reproduction device that stores a plurality of stationary natural sound material data of the same type, and sequentially connects and reproduces the sound materials by controlling selected sound material data and duration, and A stationary natural sound reproducing device characterized in that a trapezoidal time window is applied to the sound materials in response to the sound materials, and the generation timing is adjusted so that the sound materials intersect at a predetermined attenuation level position, and the sound materials are connected and reproduced. (2) The stationary natural sound reproduction device according to claim 1, characterized in that the duration is the time from -3 dB at the rise to -3 dB at the fall, and the time windows are adjusted so that they intersect at the -3 dB position. . (3) The stationary natural sound reproducing device according to claim 2, wherein the reproduction range of the sound material data is changed. (4) A pair of buffer memories that store sound material data and a pair of gates that apply a time window are provided, and the selected sound material data is stored alternately in the pair of buffer memories and the gates are controlled according to the duration. 2. The stationary natural sound reproducing device according to claim 1, further comprising a concatenation of sound materials.