JPH04200099A - Stereophonic system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stereo system, and particularly to a system that uses ultrasonic waves to create a pseudo stereo system.

[Background of the Invention] Conventionally, devices that perform processing such as phase shift, time delay, and reverberation addition on monaural audio signals are known as devices that achieve pseudo-stereo.

The present invention provides a novel pseudo-stereo system that is completely different from the conventional pseudo-stereo system as described above.

Generally, when the human ear senses the direction of sound, there are four ways to sense the direction of sound:
It is thought that there are two elements.

(1) Difference in the strength of sound entering the left and right ears.

(2) Difference in the time it takes for sound to reach the left and right ears.

(3) Differences in the phase of sound reaching each ear.

(4) Due to the sound-insulating properties of the head, if the same sound comes from a direction that is far off the midline, the frequency components of the sound entering the left and right ears will differ, resulting in different sound characteristics.

For these reasons, the sense of hearing instantly determines the direction of the sound source.

The present invention artificially creates sound image localization based on the fourth of these four principles.

On the other hand, as shown in FIG. 6, the human ear is most sensitive around 2 kHz, and cannot hear sounds below about 18 Hz and above about 18 kHz. However, the hair cells in the whorl shell in the human ear have a sensitivity up to around 90kHz, which is much higher than the above 18kHz, and send impulses to the human brain.

This is because sounds of 18 kHz or higher that cannot be heard by the human ear are not sent as audible sound information to humans, but as some other information. This information is determined to be related to the directionality of the sound.

This has been confirmed by experiments conducted by the patent applicant. In other words, when ultrasound waves of different amplitudes or frequencies are sent to the left and right ears of a person listening to monaural sound, sound image localization occurs or changes, and
You can also get sound with a three-dimensional effect.

The present invention aims to provide a stereo system based on a new system based on such circumstances.

[Means for Solving the Problem] In order to achieve this object, the present invention outputs ultrasonic waves in addition to the sound to the person who listens to the sound. Ultrasonic waves refer to sounds that are outside the human audible range, as shown in FIG. 6, and include sounds with low intensity even if the frequency is 1.8 kHz or less.

[Operation] As a result, the frequency components of the sound that enters the left and right ears of a person are different, and it is possible to experience a pseudo sense of direction and three-dimensionality of the sound. If the frequency components of the sound entering the left and right ears are the same,
The sound image localization will be at the midline.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

1. System outline Figure 1 shows the overall schematic diagram of this system.
This figure shows how the performance sound of an electronic musical instrument is made into stereo.

Two speakers 2.2 are connected to the electronic musical instrument 1 by a cord 3, so that the player of the electronic musical instrument 1 can output sound from the speakers 2.2. The sound reproduced by these two speakers 2.2 may be either stereo sound or monaural sound.

Note that the speaker 2.2 may be connected to the electronic musical instrument 1 wirelessly instead of by wire.

At the back right of the electronic musical instrument 1, there is a columnar right infrared transmitter 4r,
A left infrared transmitting section 410 and a rear infrared transmitting section 4b are installed upright and output ultrasonic signals using infrared rays as a transmission medium. These right infrared transmitting section 4r, left infrared transmitting section 4N
The rear infrared transmitter 4b can be rotated relative to the electronic musical instrument 1 to change its direction.

The above ultrasonic signal is transmitted to the right infrared receiving section 6r of the right ultrasonic speaker 5r and the left infrared receiving section 6g of the left ultrasonic speaker 5g.
, are sent to the rear infrared receiving section 6b of the rear ultrasonic speaker 5b, and the ultrasonic waves are reproduced from each of the ultrasonic speakers 5g and 5b. The ultrasonic speakers 5r, 5Ω, and 5b are provided so as to be located on the left, right, and rear sides of the listener, as shown in FIG.

The ultrasonic speakers 5 can be of a ceramic diaphragm type, for example, and can be attached to the back of a poster, painting, or the like.

2. Panel switch group FIG. 2 shows each switch in the panel switch group 3 on the electronic musical instrument 1.

In this panel switch group 13, three slide switches 7 are provided for moving the sound image localization using the three ultrasonic speakers 5, respectively. The left and right slide switch 7a moves the sound image localization left and right, the front and back slide switch 7b moves the sound image localization back and forth, and the up and down slide switch 7c moves the sound image localization up and down.

Further, the panel switch group 13 is also provided with an AM/FM switch 8. This AM/FM switch 8 is used to switch an ultrasonic signal, which will be described later, between an AM modulated signal and an FM modulated ultrasonic signal.

The panel switch group 13 also includes a group of switches for selecting effects, tones, rhythms, and the like.

The effect switch group includes compressors, limiters,
There are distortion, chorus, franchisor, excutor, phaser, autopan, harmonica, pitch shifter, etc. By applying these effects, the waveform of the musical tone signal output from the amplifier 9, which will be described later, changes in various ways.

This change is in the amplitude, frequency, phase, etc. of the musical sound waveform.

3. Whole circuit FIG. 3 shows an overall circuit diagram of the electronic musical instrument.

Each key on the keyboard] 1 is scanned by a key scan circuit 12, and data indicating key-on and key-off is detected and written into the RAM 16. Then, it is compared with data indicating the on/off state of each key previously stored in RAM 1.6, and the on event or off event of each key is determined.

Each switch in the panel switch group 13 is scanned by a panel scan circuit 14. This scan detects data indicating whether each switch is on or off.
It is written into RAM16.

The data is then compared with data indicating the on/off state of each switch that has been stored in the RAM 16 up to that point, and an on event or an off event of each switch is determined.

Note that the keyboard 1 may be replaced by an electronic stringed instrument, an electronic wind (wind) instrument, an electronic percussion instrument (pad, etc.), or the like.

The tone generator 18 generates a musical tone signal with a pitch corresponding to an on key of the keyboard 11 and a tone color corresponding to an on switch of the panel switch group 13. This total generator 18 is formed with a musical tone generation system for a plurality of channels, and can generate musical tones polyphonically.

The musical tone signal generated by the total generator 18 is outputted via the amplifier 19 and the speaker 2.2. .

The ROMI 7 stores programs, waveform data, etc. for the CPUI 5 to perform various processes, and the RAM 16
Various processing data are stored in the .

4. Infrared transmitter 4 and infrared receiver 6 In FIG. 4, the musical tone signal from the amplifier 19 is sent to three right infrared transmitters 4 r s, left infrared transmitter 4N, and rear infrared transmitter 4.
b, is converted into an ultrasonic signal using infrared rays as a transmission medium, and is outputted to the three right ultrasonic speakers 5r mentioned above.
The signal is transmitted to the right infrared receiving section 6r of the left ultrasonic speaker 5i1, the left infrared receiving section Ml of the left ultrasonic speaker 5i1, and the rear infrared receiving section 6b of the rear ultrasonic speaker 5b.

The wavelengths of the infrared rays in the right, left, and rear transmission systems are different, so that the infrared signals are not mixed.

Each infrared transmitter 4r14g, 4b, each infrared receiver 6r
, 51, and 6b have the same configuration, and of these, the right infrared transmitting section 4'' and the right infrared receiving section 6r will be explained below as an example.

The musical tone signal from one of the amplifiers is transmitted through the analog switch 2]-a or the analog switch 2 in the infrared transmitter 4.
1b, the AM modulation circuit 22 or the FM modulation circuit 2
given to 3.

On the other hand, the oscillation circuit 24 oscillates and outputs an ultrasonic signal having a frequency of 18 kHz or higher. This ultrasonic signal is
It may be set to 18 kHz or less. Oscillation circuit 24
The ultrasonic signal from the variable resistor VR1 is transmitted to the AM modulation circuit 22 or the FM modulation circuit 23 through the analog switch 2], c or the analog switch 21d.
given to. AM modulation circuit 22 or FM modulation circuit 2
3, the ultrasonic signal is subjected to AM modulation or FM modulation in accordance with the musical tone signal, as shown in FIG.

This modulated ultrasonic signal is transmitted to the analog switch 2 ]
, e or the analog switch 21f, the infrared light emitting diode 25 outputs infrared light as a transmission medium.

According to the switching of the above A M/FM switch 8, the C
P U ], 5 sets and resets the flip-flop 26. The output of this flip-flop 26 is directly connected to the analog switches 21a and 21c.

21e, and Lj to the analog switches 21b, 21d, 21f via the inverter
available. Thereby, by switching the AM/FM switch 8, switching between AM modulation and FM modulation is performed.

The ultrasonic signal using infrared light as a transmission medium output from the infrared light emitting diode 25 is transmitted to the ultrasonic speaker 5.
The light is received by the infrared light receiving diode 31 in the infrared receiving section 6 of... and converted into an electrical signal. The ultrasonic signal converted into an electric signal is sent to a demodulation circuit 32 and an amplifier 3.
0 to the ultrasonic speakers 5..., causing the ultrasonic speakers 5... to vibrate. As a result, ultrasonic signals are output from the ultrasonic speakers 5 . . . , giving the listener a pseudo-stereo effect.

The resistor that determines the oscillation frequency in the oscillation circuit 24 is a variable resistor VR2, and by changing the resistance value of this iiJ variable resistor VR2, the oscillation frequency of the ultrasonic signal is changed.

Further, by changing the resistance value of the variable resistor VRI connected to the output side of the oscillation circuit 24, the amplitude level of the ultrasonic signal from the oscillation circuit 24 is changed.

These variable resistors VRI and VH2 are provided in the three infrared transmitting sections 4, respectively, and the left and right, front and back, and upper and lower slide switches 7a and 7b.

It is linked with the 7c slide. For convenience of explanation below, the variable resistors VRI, VH2 in the right infrared transmitter 4r are referred to as right variable resistors VRI r, VH2r, and the variable resistors VRI, VH2 in the left infrared transmitter 4g are referred to as left variable resistors VRI, Q, V.
R2g, variable resistance VRI in the rear infrared transmitter 4b,
VH2 is assumed to be rear variable resistors VR1b and VR2b.

The right variable resistor VR1r and the left variable resistor VRIΩ are linked to the left and right slide switch 7a. When the left and right slide switch 7a is moved to the left position, the resistance value of the right variable resistor VR1r increases or the resistance value of the left variable resistor VRIg decreases, and the level of the ultrasonic signal from the right ultrasonic speaker 5'' increases. or the level of the ultrasonic signal from the left ultrasonic speaker 5g increases, and the sound image localization moves to the left.If the left and right slide switch 7a is moved to the right position, these operations are reversed, and the sound image localization moves to the right.

The rear variable resistor VR1b is linked to the front and rear slide switch 7b. When the front/rear slide switch 7b is moved to the rear position, the resistance value of the rear variable resistor V R1,b becomes smaller, the level of the ultrasonic signal from the rear ultrasonic speaker 5b increases, and the sound image localization moves backward.

When the front/rear slide switch 7b is moved to the front position, the operation is reversed and the sound image localization is moved forward.

In this way, the level of the ultrasonic signal can be adjusted to each ultrasonic speaker 5.
By changing r, 547, and 5b, the sound image localization moves forward, backward, left, and right. This is not just a matter of the strength of the left and right sounds, but also a complex interplay of changes in the content of harmonic components in addition to the strength of the sound, giving the listener the illusion of a change in sound image localization.

The above-mentioned right variable resistor VR2r and left variable resistor VR2N.

The rear variable resistor VR2b is connected to the above-mentioned vertical slide switch 7c.
It is linked to. When the vertical slide switch 7C is moved to the upper position, all variable resistors VR2r and VR2D
The resistance value of XVR2b changes, the oscillation frequency of each oscillation circuit 24 increases, and all ultrasonic speakers 5r, '1.5
The frequency of the ultrasonic signal from b increases, and the sound image localization moves upward. When the vertical slide switch 7c is moved to the lower position, the operation is reversed and the sound image localization moves downward. In this case, the rear ultrasonic speaker 5b
Alternatively, the frequency of the ultrasonic signal from either the right ultrasonic speaker 5r or the left ultrasonic speaker 5fI may be changed.

In this way, the frequency of the ultrasonic signal is adjusted to each ultrasonic speaker 5.
If you change r, 5g, and 5b, the sound image localization will move up and down. Psychologically, to the human ear, high-frequency sounds are heard as if they are coming from a high place, and low-frequency sounds are heard as if they are coming from a low place. This may be related to the fact that the sound image localization changes when the frequency of the ultrasound signal changes, giving the illusion of vertical displacement.

Also, according to experiments, the addition of such ultrasonic waves,
In addition to changing the sound image localization, it can also create a three-dimensional effect (sense of movement), that is, an expansion of the width of the sound image. In other words, the musical sound coming from speaker 2.2 contains a mixture of musical instrument sounds with different frequencies, but each instrument sound seems to be heard not from a single point, but from a certain range. .

This is because it is thought that the effect of the ultrasonic signal on each musical instrument sound is not uniform. This is especially true for the left and right ultrasonic speakers 5R! This is noticeable when the ultrasound signals from 5fl are synchronized as signals with the same content.

In addition, left and right ultrasonic speakers 5r, 5. In addition to the ultrasonic signal from the rear ultrasonic speaker 5b, if the ultrasonic signal from the rear ultrasonic speaker 5b is synchronized as the same signal, the width of the sound image can be expanded not only forward but also backward. It can create a feeling of being surrounded by each instrument, that is, a sense of encirclement.

Note that the variable resistor VR] may be provided on the cathode side of the infrared light emitting diode 25.According to experiments, such an upward change in sound image localization occurs when the frequency of the ultrasonic signal is 5 to 8.
This is noticeable when the frequency is around kHz, and the downward change is noticeable when the frequency is around 500Hz to 11Hz. This frequency is audible to the human ear, but There is no problem if you reduce the strength.

Note that the ultrasonic speaker 5 may also be provided in front or directly above, and the amplitude level and frequency of the ultrasonic signal from this ultrasonic speaker 5 may be changed, or the speaker 2.2 may be provided in the rear, directly above, etc. may be provided.

Conversely, there may be one speaker 2 and one ultrasonic speaker 5.

In this embodiment, since the ultrasonic signal is modulated according to the musical tone signal, it is possible to change the ultrasonic wave from the ultrasonic speaker 5 in accordance with the musical tone signal, thereby stably changing the sound image localization and width. It is possible to achieve a wide three-dimensional effect or a sense of surroundings. In particular, even when an effect that changes the amplitude or frequency of the musical tone signal described above is added, the ultrasonic signal can be changed in response to this change. Of course,
Ultrasonic signals without the above-mentioned AM modulation or FM modulation may be output from the ultrasound speakers 5 .

The ultrasonic speaker 5... has a single disk shape, but may use a plurality of disk-shaped ceramic diaphragms of different sizes, and each ceramic diaphragm outputs an ultrasonic signal of a different frequency. It is also possible to do so. In this case, the analog switches 21a to 2]fSAM modulation circuit 22, F
The M modulation circuit 23 and the oscillation circuit 24 are connected to the ultrasonic speaker 5...
- side, the infrared signal sends only a musical tone signal, and the modulated ultrasonic signal is sent to the ultrasonic speaker 5 side. Furthermore, a plurality of oscillation circuits 24 may be used to send out ultrasonic signals of different frequencies to each of the ceramic diaphragms, or an ultrasonic signal of an arbitrary frequency may be output by switching these circuits. good.

The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention. For example, the variable resistors VRI r, VRI for changing the sound image localization mentioned above
Ω, VRlb, VR2r, VRl, VR2b are transistors, FETs, VCAs (voltage controlled amplifiers) instead
, a VCO (voltage controlled oscillator), etc., and the conduction resistance of this transistor or the like may be changed by changing the base current, base voltage, or applied voltage. In this case, if the base current or the like is a sine wave whose phase is slightly shifted, the sound image localization will rotate. The base current or the like may be switched between the sine wave and the current passing through the variable resistor VR connected to the slide switch 7 .

Moreover, the infrared transmitting section 4 may be one and output each infrared signal by time-division processing. In addition, input musical tone signals to the AM modulation circuit 22 and FM modulation circuit 23 are passed through a VCF (voltage control filter).
The ultrasonic signal may be modulated by a musical tone signal of a specific frequency. In this case, the voltage applied to the VCF may be the above-mentioned sine wave. Furthermore, the slide switches 7a, 7b, 7c are the respective ultrasonic speakers 5r, 54).

The slide switches 7a, 7b, and 7c respectively correspond to the ultrasonic speakers 5r and 5b.
54), 5b may be individually rolled.

In addition, the information sent by the infrared signal may be coded information regarding the frequency, amplitude level, etc. of the ultrasonic signal, and the ultrasonic speaker 5 may generate and output the ultrasonic signal. In addition, the ultrasonic speaker 5...
It may be provided adjacent to the speaker 2.2, and in this case, the ultrasonic speaker 5... and the speaker 2... may be provided at both ends of the headphone.

In addition, other sound sources other than the electronic musical instrument 1, such as a tape recorder, a laser disk player, a television receiver, a tuner, etc., may be used as the acoustic signal output from the speaker 2.2. Also, an electronic musical instrument 1 and an ultrasonic speaker 5.
The communication medium with... may be laser, electromagnetic waves, etc., or may be wired.

[Effects of the Invention] As detailed above, the present invention provides sound listeners with the following benefits:
In addition to this sound, it also outputs ultrasonic waves. As a result, the frequency components of the sound that enters the left and right ears of a person are different, and it is possible to experience a pseudo sense of direction and three-dimensionality of the sound.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention.
Figure 2 is a schematic diagram of the stereo system, Figure 2 is a diagram showing the panel switch group 13, Figure 3 is an overall circuit diagram of an example in which the stereo system is applied to the electronic musical instrument 1, and Figure 4 is an infrared 5 is a circuit diagram of the transmitting section 4 and the infrared receiving section 6, FIG. 5 is a signal waveform diagram of each part in FIG. 4, and FIG. 6 is a diagram showing the human audible range. 1... Electronic musical instrument, 2. 2... Speaker, 3... Cord, 4... Infrared transmitter, 4r/Right infrared transmitter, 4
g...Left infrared transmitter, 4b...Rear infrared transmitter, 50
．． . Ultrasonic speaker, 5"...Right ultrasonic speaker, 5g.
・Left ultrasonic speaker, 5b...Rear ultrasonic speaker, 6
...Infrared receiving section, 6r/Right infrared receiving section, 6g...
・Left infrared receiving section, 6b...Rear infrared receiving section, 7a, 7
b % 7 c...Slide switch, 8...A
M/FM switch, 11...keyboard, 13...
Panel switch group, 15-CPU, 21a to 21f
- Analog switch, 22... AM modulation circuit, 23...
...FM modulation circuit, 24...Oscillation circuit, 25...Infrared light emitting diode, 31...Infrared light receiving diode, 32...Demodulation circuit, VRI, VR2...Variable resistor. Patent applicant: Kawai Musical Instruments Manufacturing Co., Ltd. Agent: Patent attorney: Makoto Wakahara - Figure 1 r = 6b 5b Figure 2 7 = Dan 4 q et al.

Claims (4)

[Claims] (1) An acoustic signal generating means that generates an acoustic signal that responds to human hearing, an acoustic output means that outputs the acoustic signal from the acoustic signal generating means as sound to a listener, and an acoustic signal that does not respond to human auditory sense. A stereo system comprising an ultrasonic signal generating means for generating an ultrasonic signal, and an ultrasonic output means for outputting the ultrasonic signal from the ultrasonic signal generating means as an ultrasonic wave to a listener. (2) The stereo system according to claim 1, wherein the ultrasonic signal is modulated by the acoustic signal. (3) The stereo system according to claim 1, wherein said sound output means is plural. (4) The stereo system according to claim 1, wherein said ultrasonic wave output means is plural.