JP2006304020

Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2006304020
PROBLEM TO BE SOLVED: To provide an external sound perception apparatus capable of
improving the sense of direction of a perceived sound. An external sound perception apparatus
for perceiving external sound by ultrasonic vibration, which modulates a carrier signal based on
directional microphones 10 and 10 to which the external sound is input, and an input sound
signal. And the transducers 31, 31 for transmitting ultrasonic vibration to the living body based
on the vibration signal, and the directional microphone 10 and the vibrator 31 are associated
with each other. A plurality of ultrasonic vibrations are respectively transmitted from the
corresponding transducers based on the external sound input to the directional microphones,
and the vibration signal generation unit 20 receives the ultrasonic vibrations from the directional
microphones. It is configured to be able to perform unique modulation for each external sound.
[Selected figure] Figure 2
External sound perception device
[0001]
The present invention relates to an external sound perception apparatus for perceiving external
sound by ultrasonic vibration.
[0002]
A hearing aid for the deaf person is known as an external sound perception device for perceiving
external sounds.
03-05-2019
1
Hearing aids include air-conduction-type hearing aids in which the vibration of sound is
transmitted to the brain's auditory organs via the tympanic membrane, and bone-conduction-type
hearing aids in which sound vibration is transmitted directly to the human body from the skull or
the like without tympanic membrane. The vibrator is attached to a predetermined part of the
human body and used.
[0003]
Recently, a configuration has been known in which external sound can be perceived by
transmitting ultrasonic vibrations to the auditory organs of the brain via a transducer. For
example, Patent Document 1 discloses an external sound perception apparatus configured to
transmit ultrasonic signals from a plurality of transducers based on external sound input to a
microphone. JP 2004-343302 A
[0004]
The sound image of bone conduction ultrasound may change significantly due to a subtle
difference in the mounting position of the transducer. Therefore, the device disclosed in Patent
Document 1 is configured to be able to generate different vibration signals for each of the
transducers, thereby making it possible to detect the sound sensing state (regardless of the
attachment position of the transducers to the living body). The perceptual state of the external
sound is optimized. However, since the conventional external sound perception apparatus can
not obtain the sense of direction of the sound source even if a good sound sensing state is
obtained, there is room for further improvement in this respect.
[0005]
Then, this invention aims at provision of the external sound perception apparatus which can
improve the sense of direction of a perceived sound.
[0006]
The object of the present invention is to provide a directional microphone to which an external
sound is input, a vibration signal generation means for generating a vibration signal by
modulating a carrier signal based on the input sound signal, and the vibration signal. And a
plurality of directional microphones and a plurality of transducers are provided in association
03-05-2019
2
with each other, and based on the external sound input to each of the directional microphones,
An ultrasonic vibration is transmitted from each of the corresponding transducers, and the
vibration signal generation unit is configured to be able to perform unique modulation for each
external sound input from each of the directional microphones. Achieved by a sound perception
device.
[0007]
In this external sound perception apparatus, preferably, the vibration signal generation unit is
configured to be able to perform amplitude modulation by changing the frequency of the carrier
signal for each of the directional microphones.
[0008]
Further, the vibration signal generation means may be configured to be able to perform
modulation by a different modulation method for each of the directional microphones.
[0009]
In these external sound perception apparatuses, preferably, the vibration signal generation unit
includes an input unit capable of inputting a modulation condition for performing unique
modulation for each external sound.
[0010]
According to the present invention, it is possible to provide an external sound perception
apparatus capable of improving the sense of direction of a perceived sound.
[0011]
Hereinafter, the actual mode of the present invention will be described with reference to the
attached drawings.
FIG. 1 is a front view showing a schematic configuration of an external sound perception
apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram
thereof.
03-05-2019
3
As shown in FIGS. 1 and 2, the external sound perception apparatus generates a vibration signal
based on a plurality of directional microphones 10, 10 to which an external sound is input, and
an input sound signal. 20, and a plurality of vibration transmission units 30, 30 for transmitting
mechanical vibration based on the vibration signal.
[0012]
The plurality of directional microphones 10 are attached to a casing 20 a in which the vibration
signal generation unit 20 is accommodated.
The mounting of the directional microphones 10, 10 is fixed so that the main axis directions of
the respective directivity are different in the present embodiment, but each main axis direction
may be mounted so as to be adjustable.
The external sound input to each of the directional microphones 10 and 10 is input to the
vibration signal generation unit 20 after amplification processing is performed.
[0013]
The vibration signal generation unit 20 includes carrier signal generation units 22 and 22 that
generate a carrier signal, input units 24 and 24 that can input the frequency, amplitude, timing
(phase) and modulation method of the carrier signal, and the directional microphone 10. 10, and
carrier signal modulators 26, 26 for generating a vibration signal by modulating the carrier
signal based on the sound signals input from 10, 10, and individually for each input sound of the
directional microphones 10, 10. Generate a vibration signal.
[0014]
The input unit 24 includes an individually adjustable volume switch 24a so that the frequency,
amplitude, and phase of the carrier signal can be continuously changed, and further, a dial switch
24b for selecting a modulation scheme. Is equipped.
As selectable modulation methods, frequency modulation, amplitude modulation, phase
modulation, etc. may be mentioned, and further, as types of amplitude modulation, for example,
03-05-2019
4
double side band (DSB), single side band (suppressed carrier) (SSB), etc. Can be selected.
[0015]
The frequency of the carrier signal is preferably 20 to 100 kHz, more preferably 20 to 50 kHz,
which is an ultrasonic wave range, so that even a high-grade deaf person can obtain a good
sound sensing state.
Therefore, it is preferable that the input unit 24 be able to adjust the frequency of the carrier
signal in a range including a part or all of the above frequency range.
[0016]
The vibration transfer units 30, 30 each include a vibrator for transmitting a vibration signal to
the outside as mechanical vibration, and each vibrator is associated with each of the plurality of
directional microphones 10, 10, and any one of the directivity is The external sound input to the
sexual microphone 10 is transmitted from the corresponding vibrator.
[0017]
As shown in FIG. 3, each vibration transmitting unit 30 includes a cylindrical case 32 in which
the vibrator 31 is accommodated, and is configured by attaching a suction disk 34 to the opening
edge of the case 32.
[0018]
The vibrator 31 is supported swingably around two axes orthogonal to each other by a gimbal
mechanism.
That is, the vibrator 31 is fixed to the first frame 40 so as to expose the vibration surface, and the
first frame 40 is fixed to the second frame 44 through the first support shaft 42. It is swingably
supported.
The second frame 44 is swingably supported inside the case 32 via a second support shaft 46
03-05-2019
5
orthogonal to the first support shaft 42.
The vibrating surface of the vibrator 31 slightly protrudes from the opening of the case 32, and
when the suction disk 34 is adsorbed to a predetermined attachment site, the vibrating surface of
the vibrator 31 is configured to contact and press the adsorption surface. It is done. A
communication hole 32a is formed at the center of the bottom of each case 32 (the upper part in
the figure), and a spherical bag-like body 48 is connected to the communication hole 32a. The
bag-like body 48 is made of an elastic material such as a rubber material, and is configured to be
elastically deformable by pressing. The internal space of the bag-like body 48 is in
communication with the inside of the case 32 through the communication hole 32a.
[0019]
Next, the operation of the external sound perception apparatus will be described. First, the
plurality of vibration transmitting units 30, 30 are attached to predetermined portions of the
human body (for example, in the vicinity of the left and right mastoid projections). Each vibrator
31 can be reliably brought into contact with the human body by the gimbal mechanism by
pressing the suction cup 34 against a predetermined portion in a state where the bag-like body
48 is picked by hand. After that, when the hand which has been picked up is released, the inside
of the case 32 becomes a negative pressure by the shape restoring force of the bag-like body 48
and the adsorption force is obtained, so that the attachment of the vibrator 31 can be ensured.
[0020]
Thereafter, when the switch of the external sound perception apparatus is turned on and an
external sound is input to the directional microphones 10, 10, a sound signal is input from the
directional microphones 10, 10 to the vibration signal generation unit 20. The directional
microphones 10, 10 have different principal axes of directivity, so the input sensitivity to the
same sound source is different.
[0021]
In the vibration signal generation unit 20, the carrier signal generation units 22, 22 generate a
carrier signal having a predetermined amplitude and frequency, and the carrier signal
03-05-2019
6
modulation units 26, modulate the carrier signal based on the sound signal. Thus, the vibration
signal corresponding to the input sound to each directional microphone 10, 10 is generated. At
this time, mutually different modulation conditions are input through the input unit 24 so that
the carrier signal modulation units 26, 26 perform unique modulation for each input sound to
the directional microphones 10, 10, respectively. . For example, the frequency of the carrier
signal can be set to be different for each of the directional microphones 10 and 10, and the
modulation scheme can perform unique modulation as the same double sideband amplitude
modulation. Alternatively, the carrier signals may have the same frequency, and the modulation
schemes may be different from each other (for example, one may be double side band amplitude
modulation and the other may be suppressed carrier amplitude modulation) to perform unique
modulation. The vibration signal generated in this manner is output to the corresponding
vibration transmission units 30, 30, respectively.
[0022]
The vibration transmitting units 30, 30 vibrate the vibrators 31, 31 based on the input vibration
signal. As a result, based on the external sound input to each of the directional microphones 10,
ultrasonic vibration is transmitted to the human body from the corresponding vibration
transmitting unit 30, 30, respectively. The carrier signal modulation unit 26 controls so as not to
output the vibration signal during a period in which the sound signal is not input.
[0023]
According to the external sound perception apparatus of the present embodiment, the vibration
signal generation unit 20 is configured to be able to perform unique modulation for each
external sound input from each of the directional microphones 10 and 10. Each modulation
condition is set in advance so that the difference in "hearing (tone)" of ultrasonic vibration
transmitted from each vibration transmitting unit 30, 30 can be recognized, and directional
microphones 10, 10 corresponding to each "hearing". The user can determine which directional
microphone 10 the perceived ultrasound signal has been input from by the user grasping. For
example, when the modulation scheme is double-sided band amplitude modulation, both the
carrier wave pitch and the demodulated signal wave pitch are perceived simultaneously, while
when the modulation scheme is suppressed carrier amplitude modulation, the carrier wave Since
the pitch of H is not perceived but only the pitch corresponding to twice the frequency of the
original signal wave is perceived, the difference in "hearing" can be determined with certainty. As
a result, the user can reliably recognize the direction of the sound source such as voice and
environmental sound, which is effective, for example, when working at a disaster site or a
03-05-2019
7
construction site or driving a vehicle such as an automobile.
[0024]
In the present embodiment, although the positional deviation of the vibrator 31 over time can be
effectively prevented by the above configuration of the vibration transmission unit 30, the sound
pressure distribution in the head is determined by the attachment position of each vibrator 31. It
is difficult to correctly attach each transducer 31 to a portion where the sensory change state is
optimum, because it changes significantly due to a slight difference of Therefore, after each
transducer 31 is attached, the frequency, phase, amplitude, etc. of the carrier signal
corresponding to each transducer 31 are adjusted by the operation of the input unit 24, and the
positions of belly and nodes generated by the interference of ultrasonic waves are controlled.
Alternatively, it is preferable to optimize the sound sensing state by focusing the ultrasonic waves
and locally increasing the sound pressure. When the carrier signal frequency is set to be different
for each of the directional microphones 10 and 10 as the modulation condition, the adjustment
of the carrier signal in the adjustment of the sound sensing state is performed so that the sense
of direction of the perceived sound is not lost. Preferably the frequency is not changed.
[0025]
Although the specific method for optimizing the sound sensing state is not particularly limited,
for example, the following method can be mentioned. First, the amplitudes of the ultrasonic
waves emitted from the plurality of transducers 31 are set to be smaller, and are appropriately
attached to the mastoid so that the sound sensing state becomes substantially good. Perform
positioning. Then, the frequency and the phase of each transducer 31 are adjusted and
determined so that the sound sensing state becomes better. For example, when two vibrators 31
are attached and used, the frequency of the carrier signal corresponding to each vibrator 31 is
simultaneously changed to set the frequency at which the sound sensing state becomes the best.
After that, by setting the phase of the carrier signal corresponding to each transducer 31 in the
same manner, the optimum frequency and phase of the carrier signal can be individually
obtained for each transducer 31. Can be optimized. The setting of the frequency and the phase
may be first. Finally, the amplitude is set to the desired magnitude so as to obtain the desired
arousal state.
[0026]
03-05-2019
8
As a method of optimizing the sound sensing state, other than this, the carrier signal
corresponding to the other transducer 31 is maintained while the frequency, phase and
amplitude of the carrier signal corresponding to one transducer 31 are maintained at
predetermined values. It is also possible to optimize the perceptual state by sequentially
changing the frequency, phase and amplitude of. In this case, the frequency, phase and amplitude
of the carrier signal corresponding to the at least one vibrator 31 may be adjustable at the input
unit 24.
[0027]
In any case, by adjusting the frequency, phase and amplitude of the carrier signal in a state
where the difference in "hearing" can be determined with certainty, it is possible to obtain both a
good sound sensing state and a sense of direction.
[0028]
As mentioned above, although one embodiment of the present invention was explained in full
detail, the concrete mode of the present invention is not limited to the above-mentioned
embodiment.
For example, in the present embodiment, two directional microphones 10 and 10 are used to
perform unique modulation on each input sound, but the directional microphone and the
vibration transmission corresponding thereto are used. The number of parts is not particularly
limited as long as it is plural. For example, when this external sound perception apparatus is
installed in an automobile, the four directional microphones are fixed to the vehicle so that the
principal axes of directivity are forward, backward, rightward, and leftward, respectively, and
each input is The sound may be uniquely modulated and then transmitted to the human body via
the corresponding four vibration transmitters. This makes it possible to reliably grasp the
direction of a sound source such as a siren of an emergency vehicle that needs to be recognized
during driving.
[0029]
Further, in the present embodiment, although the modulation condition can be input through the
input unit 24, the modulation condition suitable for the user is determined in advance and the
03-05-2019
9
data is stored in a memory or the like. Alternatively, the input unit 24 may not be provided.
Further, the input of the change condition from the input unit 24 is not limited to the manual
operation, but may be configured such that the result of measurement and calculation by another
device is automatically input.
[0030]
First, in order to investigate whether the subject can distinguish the presenting site of the
ultrasonic bone conduction sound, the brain magnetic field (MEG) when the bone conduction
ultrasonic stimulation is presented to the left and right mastoid according to the oddball task is It
measured. The application of bone conduction ultrasound stimulation was performed by 30 kHz
ultrasound amplitude-modulated (100% modulation rate) with a tone burst of frequency 1 kHz
(duration 30 ms, rise and fall times 10 ms each), and one side of the mastoid and When the low
frequency stimulus (presentation probability 10%) and high frequency stimulus (presentation
probability 90%) are given to the other side respectively, the brain magnetic field when the right
side is low frequency stimulus (the left side is high frequency stimulus) and Was compared with
the case of low frequency stimulation (high frequency stimulation on the right).
[0031]
FIG. 4 (a) shows the waveform of the brain magnetic field measured in the right side head of the
subject for each of the low frequency stimulation and the high frequency stimulation. In all cases,
the N1m response was observed about 100 ms after the presentation of the stimulus, but the low
frequency stimulus had a larger amplitude of the N1m response and a mismatch response was
observed. For comparison, when the same measurement was performed with a bone conduction
audible sound at a frequency of 2 kHz, as shown in FIG. 4 (b), also in this case, a mismatch
reaction was observed at the same latency.
[0032]
From the above, it is objective that the two bone conduction ultrasound stimulations can be
discriminated as in the case of the bone conduction audible sound and that the subject can
discriminate the presentation site (presentation side) of the ultrasound bone conduction sound. It
was possible to clarify.
[0033]
03-05-2019
10
Next, in order to check whether or not the input sound itself presented to the mastoid can be
discriminated, the frequency of the carrier signal is made to be different for each directional
microphone 10, 10 as the modulation condition in the above embodiment of the present
invention When the modulation method is the same both-sideband amplitude modulation, the
relationship between the frequency of the sinusoidal bone conduction sound and the pitch (the
subjective sound pitch) is It measured against.
[0034]
The pitch is measured in a non-acoustic room, and a piezoelectric ceramic vibrator is fixed to the
mastoid on one side of the subject with a headband to present bone conduction sound, while the
other side is air-guided through headphones. When the sound is presented and the bone
conduction sound of each frequency of 16k, 20k, 24k, 28k, 32k, 36k and 40k (Hz) is presented,
the frequency of the air conduction sound which makes the pitch equal is adjusted. It is
determined by a method of changing the frequency of air conduction sound by dial adjustment or
the like.
The measurement was performed twice by switching the presenting side of the bone conduction
sound and the air conduction sound, and the average value of these two times was calculated for
each subject.
The results are shown in FIG.
[0035]
As shown in FIG. 5, in the ultrasonic frequency band, there is no monotonically increasing
relationship between the bone conduction frequency and the pitch as in the case of an audible
sound, and furthermore, the variation pattern is seen depending on the subject However, in any
of the test subjects, it can be seen that the pitch fluctuates 1 to 2 kHz up and down with the
increase of the bone conduction frequency. If there is a pitch fluctuation of this degree, the test
subject can easily distinguish the difference. Therefore, in an actual product, a bone conduction
sound frequency in which the pitch difference can be easily distinguished is selected in advance,
and the selected bone is selected. By making the sound induction frequency the frequency of the
carrier signal, the inputs from the plurality of transducers can be clearly distinguished.
03-05-2019
11
[0036]
It is a front view which shows schematic structure of the external sound perception apparatus
which concerns on one Embodiment of this invention. It is a block diagram of the said external
sound perception apparatus. It is sectional drawing of the vibration transmission part in the said
external sound perception apparatus. It is a figure which shows the experimental result for
verifying the effect of the external sound perception apparatus shown in FIG. It is a figure which
shows the other experimental result for verifying the effect of the external sound perception
apparatus shown in FIG.
Explanation of sign
[0037]
10 directional microphone 20 vibration signal generation unit 22 carrier signal generation unit
24 input unit 26 carrier signal modulation unit 30 vibration transmission unit 31 vibrator
03-05-2019
12

Download Report