JP2012033988A - Method for generating super deep bass sound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause a listener to obtain body sensory acoustic vibration easily and in a free state by using a device having a sound output function without any vibration element mounted.SOLUTION: A method for generating super deep bass sound having frequency below an audible frequency band of human uses an output device to generate sound by outputting electrical signals from left and right channels. The method includes outputting a first frequency electric signal from the left channel and outputting a second frequency electric signal from the right channel where a difference between the first and second frequencies is less than 20 Hz.

Description

  The present invention relates to a super heavy bass generation method, and more particularly to a technique preferably applied when generating a sound having a frequency lower than a human audible frequency band.

  The sense that the sound pressure is felt by vibrating the body, the sense that is sensed by being transmitted through the floor and the ground, and the like are called bodily sensation acoustic vibrations. This body sensation acoustic vibration is used not only for audio for increasing the feeling of deep bass, but also for sound effects such as simulation and virtual reality. In addition, body acoustic vibrations are effective in various fields, such as application to music therapy that uses the relaxation effect, as well as use for the purpose of alcoholic fermentation, aging promotion, and quality improvement. Has been.

  As a means for generating the body sound vibration, a dedicated device (body sound device) can be mentioned. This body sensation sound apparatus is provided with a vibration transducer (vibration element), converts an electric signal in a low frequency band into body sensation sound vibration by the vibration element, and outputs sound in an audible frequency band as music together with the vibration, for example. Examples of the body sensation sound device include headphones and chairs.

  As a headphone-type body sensation acoustic device, Patent Document 1 discloses a beat detection unit that detects a beat from an audio signal stored in an audio signal storage unit, and a stimulation signal generation unit that generates an electric signal based on the detected beat. And a stimulus imparting unit that imparts a vestibular sense stimulus to the listener by the generated electrical signal. In the acoustic sensation apparatus, a voice sending unit (speaker) attached to the ear part of the listener outputs an audio signal as music, and a stimulus applying part attached to the peripheral part of the ear part of the listener sends an electrical signal to the vestibular sensory stimulus. Output as.

  As a chair-type body sensation acoustic device, Patent Document 2 discloses a receiver unit that receives an acoustic signal transmitted from an acoustic player, a speaker unit that receives a signal from the receiver unit and utters a sound, and a receiver unit. A body sensation sound system having a vibrator unit that receives a signal and generates vibration, and a seat unit that accommodates the speaker unit and the vibrator unit therein is disclosed. In the body sensation sound system, the receiver unit extracts a low-frequency component from the received acoustic signal and transmits it as a vibration signal to the vibrator unit, and transmits the acoustic signal to the speaker unit. The vibrator unit transmits the vibration signal. Converts to mechanical vibration to generate vibration.

JP-T-2006-85401 JP 2008-92122 A

  By the way, it is known that the frequency range of sound that human hearing can recognize is generally about 20 Hz to 20 kHz. Considering, for example, 100 Hz or less as a frequency band for obtaining body acoustic vibrations, as the frequency band becomes lower, the sensitivity of the auditory sense decreases and becomes difficult to hear, whereas the sense of vibration becomes more sensitive and can be felt as vibration. It becomes like this. When the frequency band is 20 Hz or less, it is possible to allow the listener to feel only vibrations well. That is, it can be said that it is preferable that the frequency band is 20 Hz or less as the sensible acoustic vibration that is felt by vibrating the body with sound pressure.

  In the invention of Patent Document 2, the device itself is relatively large, and the installation location is limited. Further, although the invention of Patent Document 1 is a headphone type, it is relatively small. However, in order for the listener to obtain the effect of body acoustic vibration, it is necessary to wear the device and bring the vibrating element into contact with the body (ear part). There is this (this is also the case with the invention of Patent Document 2, and it is necessary to sit on the device and bring the body into contact with the vibration element). For example, these devices cannot be used when a listener who is away from the device wants to obtain the effect of vibro-acoustic vibration, or when he / she wants to use it for fermentation of alcohol as described above.

  As a method of obtaining the effect of body sensation and acoustic vibration without bringing the vibration element into contact with the body, for example, it is conceivable to use a music reproducing device that reproduces music data on a recording medium such as a CD. However, a CD or the like used as a recording medium for music has a lower limit of a signal recordable frequency of about 20 Hz because of the relationship with human audible frequencies, and a signal having a frequency band of 20 Hz on such a recording medium. Cannot be recorded, and the above-mentioned music reproduction device or the like cannot output sound having a frequency band of 20 Hz or less.

  Therefore, in view of the above-described circumstances, the present invention enables a listener to obtain sensory acoustic vibration easily and freely using a device having a sound output function without mounting a vibration element. With the goal.

  The present invention relates to a method for generating a super-low sound that generates a sound having a frequency lower than a human audible frequency band, and outputs a first sound from a left channel using an output device that generates an electric signal from left and right channels. An electric signal having a frequency is output, and an electric signal having a second frequency whose difference from the first frequency is less than 20 Hz is output from the right channel.

  Further, according to the present invention, in the above-described super-low bass generation method, two output devices are used, and the third frequency and the third frequency from the left and right channels in one output device are less than 50 Hz. In a state where a signal is being output, an electrical signal having a first frequency and a second frequency may be output by another device.

  Moreover, in the above-described super heavy bass generation method, the present invention may be such that the difference between the first frequency and the second frequency and the difference between the third frequency and the fourth frequency are the same.

  Further, in the above-described super heavy bass generation method, the first frequency and the third frequency may be the same, and the second frequency and the fourth frequency may be the same.

  Further, according to the present invention, when sound is generated outdoors or indoors in the above-described super-low sound generation method, the difference between the third frequency and the fourth frequency is less than 20 Hz, and the generated sound is recorded on a predetermined recording medium. In this case, the difference between the third frequency and the fourth frequency may be 20 to 35 Hz.

  Further, according to the present invention, in the super heavy bass generation method described above, the first step of extracting a low frequency portion of the electric signal of the original sound to be output by a filter and the reproduction method of the electric signal extracted in the first step are set to monaural. The second step, the third step for branching the output destination of the electrical signal set in the second step to the left and right channels, and the pitch shift to each or one of the electrical signals branched in the third step, A fourth step of generating an electric signal and an electric signal of the second frequency, and a fifth step of outputting the electric signals of the first frequency and the second frequency generated in the fourth step from the left and right channels. There may be.

  According to the present invention, in the above-described super heavy bass generation method, the fourth step generates a third frequency electric signal and a fourth frequency electric signal by performing a pitch shift, and the fifth step is a fourth step. The generated third frequency and fourth frequency electrical signals may be output from the left and right channels.

  According to the present invention, it is possible for a listener to obtain body sensation vibration in a simple and free state using a device that does not have a vibration element and has a sound output function.

It is the figure which showed the structure of the audio | voice reproduction apparatus which concerns on embodiment of this invention. It is a figure for demonstrating a beat phenomenon. It is the figure which showed the structure of the audio | voice reproduction apparatus which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment]
The first embodiment of the present invention is an apparatus that reproduces music data on a recording medium such as a CD, and has a frequency band using a general music reproduction apparatus that does not include an oscillating element that converts an electric signal into vibration. Produces a sound of 20 Hz or less, and obtains the effect of sensible acoustic vibration that is felt by vibrating the body with sound pressure.

  FIG. 1 is a diagram showing a configuration of a music playback device used in the present embodiment. The music playback device 1 of this embodiment includes a left channel audio signal acquisition unit 10a, a right channel audio signal acquisition unit 10b, a left channel low pass filter unit 11a, a right channel low pass filter unit 11b, a left channel band bus filter unit 12a, and a right channel. Bandpass filter unit 12b, monaural setting unit 13, channel branching unit 14, left channel signal processing unit 15a, right channel signal processing unit 15b, left channel superimposing unit 16a, right channel superimposing unit 16b, left channel amplifying unit 17a, right channel It has an amplifying unit 17b, a left channel output unit 18a, and a right channel output unit 18b.

  The left channel audio signal acquisition unit 10a acquires an audio signal as music data such as music from a recording medium such as a CD. The audio signal may be compressed in a predetermined compression format (for example, MP3). In this embodiment, it is assumed that the music playback device 1 plays back music data on a recording medium such as a CD. However, music data is acquired from the recording medium and stored as compressed data, or a network such as the Internet. It is also possible to use it by downloading it from the Internet and saving it as compressed data. In such a case, an audio signal storage unit that stores the audio signal in a compressed state may be provided together with (or instead of) the left channel audio signal acquisition unit 10a. The operation of the right channel audio signal acquisition unit 10b is the same as described above.

  The left channel low-pass filter unit 11a receives an input from the left channel audio signal acquisition unit 10a, extracts a bass part, that is, an audio signal having a predetermined frequency or less (eg, 100 Hz or less) from the input audio signal, and a monaural setting unit 13 is output. The left channel band-pass filter unit 12a extracts an audio signal (for example, a signal exceeding 100 Hz) other than the audio signal extracted by the left channel low-pass filter unit 11a and outputs the audio signal to the left channel superimposing unit 16a. The operations of the right channel low-pass filter unit 11b and the right channel band bus filter unit 12b are the same as described above.

  The monaural setting unit 13 sets the signal reproduction method (output method) to monaural for the bass audio signal input from the left channel low-pass filter unit 11 a and the right channel low-pass filter unit 11 b and outputs the monaural signal to the channel branch unit 14. To do. The channel branching unit 14 branches the audio signal input from the monaural setting unit 13 into left and right channels, and outputs them to the left channel signal processing unit 15a and the right channel signal processing unit 15b.

  The left channel signal processing unit 15a performs a pitch shift on the audio signal input from the channel branching unit 14, generates an audio signal having a different frequency, and outputs the audio signal to the left channel superimposing unit 16a. The pitch shift may be configured to be performed on the audio signal of each channel, or may be configured to be performed on the audio signal of one channel. The operation of the right channel signal processing unit 15b is the same as described above.

  The left channel superimposing unit 16a superimposes the monaural audio signal input from the left channel signal processing unit 15a and the stereo audio signal unit other than the low sound input from the left channel bandpass filter unit 12a, Output to the left channel amplifier 17a. The left channel amplifying unit 17a amplifies the audio signal input from the left channel superimposing unit 16a, and outputs the amplified audio signal to the left channel output unit 18a according to the audio signal output method. The left channel output unit 18a is a left channel speaker, converts the audio signal input from the left channel amplification unit 17a into sound, and outputs the sound to the listener. The operations of the right channel superimposing unit 16b, the right channel amplifying unit 17b, and the right channel output unit 18b are the same as described above.

  FIG. 2 is a diagram for explaining a beat phenomenon caused by the synthesis of two waves having similar frequencies. 2A shows a waveform graph of each wave, and FIG. 2B shows a waveform graph of a synthesized wave. As shown in FIG. 2 (a), the P wave and the Q wave have a wave size of 1, but have different periods because of different frequencies. The P wave + Q wave obtained by synthesizing them has a waveform as shown in FIG. The magnitude of the wave is a total of 1 for both waves at the maximum, and a value close to 0 at the minimum.

  Thus, when there are two waves (sound sources) and their frequencies are slightly different, the sound becomes louder or louder. When two mountain peaks (wave magnitude 1 or -1) overlap, the sound becomes louder, and when a mountain and valley (wave magnitudes 1 and -1) overlap, the sound becomes louder. This is called a beat phenomenon. In the present invention, this beat phenomenon is used to create a 20 Hz wave (sound source) that does not exist electrically.

  In the example described above, when the audio signal of 100 Hz or less that has passed through the left low-pass filter unit 11a (right low-pass filter unit 11b), monaural setting unit 13, and channel branching unit 14 is 70 Hz, the left channel signal processing unit 15a Assume that the left channel 75 Hz audio signal is generated by the pitch shift and the right channel signal processing unit 15 b generates the right channel 65 Hz audio signal by the pitch shift. At this time, 10 Hz that does not exist electrically is generated in the space due to the beating phenomenon.

  That is, when a 75-Hz audio signal is output from the left channel output unit 18a and a 65-Hz audio signal is output from the right channel output unit 18b, the listener actually listens to 75 Hz and 65 Hz sounds, as if 10 Hz. It is possible to produce a sensible acoustic vibration that is felt by vibrating the body with the sound pressure when listening to the ultra-low sound.

[Second Embodiment]
In the first embodiment described above, a super heavy bass having a frequency band of 20 Hz or less is created in a space using a general music playback device. However, a slight time lag (1 to 2 ms) is generated in the production of the super heavy bass by the method. May occur. This time lag is the time taken for the above-mentioned beat phenomenon to occur. Due to the occurrence of the time lag, the listener feels at a timing when the sensory sound vibration is shifted and feels somewhat uncomfortable, so that the effect of precious feeling due to the sensory sound vibration is also halved. Therefore, as a second embodiment of the present invention, a method for eliminating the time lag will be described.

  In the present embodiment, two music playback devices are used, one device generates super heavy bass in advance, and the other device plays the super heavy bass together with the music in a state where the super heavy bass is output. It is desirable that the apparatus that reproduces the super heavy bass beforehand generates only the super heavy bass without reproducing the music. This is because, since the playback start points of the two units are different, if the music is played back by the two devices, the output music is heard by the listener with a shift. In the case of using two devices that reproduce music along with ultra-low sounds (the music reproducing device of the first embodiment), it is necessary to adjust the output music so that it is not heard by the listener.

  FIG. 3 is a diagram showing the configuration of a music playback device (a device that plays back super heavy bass in advance) used in the present embodiment. The basic configuration is the same as that of the music playback device of the first embodiment, but compared to the music playback device, the left channel band bus filter unit 12a, the right channel band bus filter unit 12b, the left channel superimposing unit 16a, the right channel The channel superimposing unit 16b is not provided, and only the super heavy bass is generated as described above.

  The music playback device 2 of this embodiment includes a left channel audio signal acquisition unit 20a, a right channel audio signal acquisition unit 20b, a left channel low-pass filter unit 21a, a right channel low-pass filter unit 21b, a monaural setting unit 23, a channel branching unit 24, It includes a left channel signal processing unit 25a, a right channel signal processing unit 25b, a left channel amplification unit 17a, a right channel amplification unit 17b, a left channel output unit 18a, and a right channel output unit 18b. An audio signal having a predetermined frequency or less that has passed through the left channel low-pass filter unit 21a, the monaural setting unit 23, and the channel branching unit 24 from the left channel audio signal acquisition unit 20a is subjected to pitch shift by the left channel signal processing unit 25a, and the right and left It is processed into signals with different frequencies in the channel. The audio signals of the respective channels having different frequencies are amplified by the left channel amplifying unit 17a, converted into sound by the left channel output unit 18a, and output. The operation for the right channel is the same as described above. The sound output from each channel output unit creates a super heavy bass of 20 Hz or less that does not exist electrically in the space due to the beat phenomenon.

The reason why the time lag described above is eliminated by the method according to the present embodiment is as follows. There are two phenomena recognized as time lag.
1. Range in which both left channel and right channel sounds reach when the signal input voltage to the time lag amplifier (left channel amplifier 17a, right channel amplifier 17b) that occurs under insufficient input conditions is not at a sufficient level May become narrower and the space in which the beat phenomenon occurs may narrow or disappear. At this time, depending on the volume of the music, there may be a time when the beating phenomenon is heard and a time when the sound is not heard. This was misunderstood like a time lag.
2. Time lag that occurs even under sufficient input conditions Occurrence may be delayed for the first moment that should occur, and the cause is not certain, but the expansion and contraction of air, temperature, and the first slight amount of applicable sound It is considered that the difference between the left and right frequencies becomes large at the part, and the beat phenomenon hardly occurs. Note that the beat phenomenon is less likely to occur when the difference between the left and right frequencies opens.

  As for the time lag in the first case, beat development occurs with a slight change by continuously applying a constant signal. Further, by securing a voltage at a limit level of whether or not to occur (a voltage level at the last minute that generates a slight bass sound), it is possible to avoid disappearance of a space in which a beat phenomenon can be heard and to expand the space. The solution is the same for the time lag in the second case, and it is possible to improve the time lag considerably by adding a constant signal continuously. In this way, in any case, a constant signal is continuously applied to create a state where a heavy bass can be generated at any time in the space itself, avoiding the disappearance of the space where the beating phenomenon can be heard, Enlarging.

  For example, when playing music outdoors such as live music, it is desirable to generate a super heavy bass of less than 20 Hz by the music playback device 2 and to play the music by the music playback device 1 so as to mix it. Further, when recording music data such as music on a recording medium such as a CD, the music playback device 2 generates a super heavy bass of 20 to 35 Hz, and the music playback device 1 plays back the music so as to mix it. It is desirable to record on a recording medium.

  There is no problem even if the super heavy bass generated by the music playback apparatus 1 and the super heavy bass generated by the music playback apparatus 2 are different frequencies, and it is better if they are the same frequency. Further, when these super heavy bass sounds have the same frequency, the frequency of the sound output from each channel output unit may be different or the same. Specifically, in the example of the first embodiment, when the music playback device 1 generates an audio signal of 75 Hz of the left channel and 65 Hz of the right channel by pitch shift to create a super heavy bass of 10 Hz, the music playback device 2 The same frequency (left channel 75 Hz, right channel 65 Hz) may be output from each channel to create a 10 Hz super heavy bass, or the left channel 30 Hz and right channel 20 Hz may be output from each channel to create a 10 Hz super heavy bass. Also good.

  In this way, in this embodiment, two music playback devices are used, and one device previously adds a last-minute voltage (a voltage at a limit level) that slightly generates heavy bass, and the signal is output. Since the other device plays a super-heavy bass with the other device, the time lag as the time it takes for the beat to occur can be eliminated, and the listener can feel the sensation and vibration of the body without feeling uncomfortable. Can be created.

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, since a large-scale device such as a means for notifying a hearing-impaired person of the approach of an electric vehicle or a hybrid vehicle is not necessary, it can be used as a warning to a hearing-impaired person in various places. In addition, when a device to which this technology is applied is installed on the ceiling, it can also be applied as means for instructing a visually impaired person on a walking course without using Braille blocks.

  In addition, a woofer or subwoofer using a large speaker is used as an acoustic device that outputs a heavy bass. However, when the method of the present invention is applied, a super-heavy bass can be generated by a small speaker. The size of the apparatus can be reduced. In addition, when applied to a mobile phone, it is possible to generate vibration without using a motor vibrator, or to generate heavy bass in the music playback function.

1, 2 Music playback device 10a, 20a Left channel audio signal acquisition unit 10b, 20b Right channel audio signal acquisition unit 11a, 21a Left channel low pass filter unit 11b, 21b Right channel low pass filter unit 12a Left channel band bus filter unit 13, 23 Monaural setting unit 14, 24 Channel branching unit 15a, 25a Left channel signal processing unit 15b, 25b Right channel signal processing unit 16a Left channel superimposing unit 16b Right channel superimposing unit 17a, 27a Left channel amplifying unit 17b, 27b Right channel amplifying unit 18a , 28a Left channel output unit 18b, 29b Right channel output unit

Claims (7)

A method for generating a super heavy bass that generates a sound having a frequency lower than a human audible frequency band,
Using an output device that generates sound by outputting electrical signals from the left and right channels, a second frequency electrical signal is output from the left channel and the difference from the first frequency is less than 20 Hz from the right channel. A method for generating a super heavy bass, comprising outputting an electrical signal having a frequency.   In the state where two output devices are used and an electric signal having a fourth frequency in which the difference between the third frequency and the third frequency is less than 50 Hz is output from the left and right channels with one output device. The method of claim 1, wherein the electrical signals of the first frequency and the second frequency are output by the method.   The method for generating super-low bass according to claim 2, wherein the difference between the first frequency and the second frequency is the same as the difference between the third frequency and the fourth frequency.   4. The method of generating super-low bass according to claim 2, wherein the first frequency and the third frequency are the same, and the second frequency and the fourth frequency are the same.   When the sound generation is performed outdoors or indoors, the difference between the third frequency and the fourth frequency is less than 20 Hz, and when the generated sound is recorded on a predetermined recording medium, the third frequency and the fourth frequency are recorded. The method for generating a super-heavy bass according to any one of claims 2 to 4, wherein the frequency difference is 20 to 35 Hz. A first step of extracting a low frequency portion of the electric signal of the original sound to be output by a filter;
A second step of setting the reproduction method of the electrical signal taken out in the first step to monaural;
A third step of branching the output destination of the electrical signal set in the second step into left and right channels;
A fourth step of generating a first frequency electrical signal and a second frequency electrical signal by performing a pitch shift on each or one of the electrical signals branched in the third step;
A fifth step of outputting the electrical signals of the first frequency and the second frequency generated in the fourth step from left and right channels;
The method for generating super-low bass according to any one of claims 2 to 5, wherein: The fourth step generates the third frequency electrical signal and the fourth frequency electrical signal by performing the pitch shift,
The method of claim 6, wherein the fifth step outputs the third frequency and the fourth frequency electrical signals generated in the fourth step from left and right channels.

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