close

Вход

Забыли?

вход по аккаунту

?

JP2004112528

код для вставкиСкачать
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 JP2004112528
[Problem] In a hands-free call, the contents of the call can be heard by the passenger in the front
passenger seat, and the passenger can not feel uncomfortable, can not protect privacy, and can
keep confidentiality. A plurality of speakers are installed in a vehicle cabin, and phases are
adjusted and output so that output sounds of the speakers are emphasized at a position of a
hands-free user's ear. Furthermore, the influence of the displacement of the position of the ear is
reduced by outputting the high frequency component of the original voice from the speaker at a
position where the influence of the movement of the position of the driver's ear is small.
[Selected figure] Figure 1
Acoustic signal transmission apparatus and method
TECHNICAL FIELD [0001] The present invention relates to an acoustic signal transmission
apparatus and method. 2. Description of the Related Art With the explosive spread of mobile
phones in recent years, there has been an increasing demand for making calls even when driving
a car. However, it is dangerous for the driver to secure a mobile phone and talk during driving,
which is a problem from the viewpoint of safety. Therefore, there is a growing demand for a
hands-free communication device in which a driver makes a call by using a microphone and a
speaker for loud-speaking installed in a car without securing a mobile phone while driving. In the
hands-free communication device in the conventional form, the voice of the other party is output
from the existing audio speaker and transmitted to the driver. However, in such a configuration,
when there is a passenger in the front passenger seat or the like, the call content may be heard
by the passenger. Depending on the contents of the call, it may not be preferable, and there are
problems in terms of privacy protection and confidentiality. In order to solve this problem, an
audio signal transmission device is required to transmit the call sound only to the handsfree user.
As a technique for transmitting sound only to a certain spot, a parametric speaker using
09-05-2019
1
ultrasonic waves has been reported (see, for example, Patent Document 1). As another technique,
there is a method of adjusting and outputting a phase relationship so that sounds overlap in a
target area from a plurality of nondirectional speakers (see, for example, Patent Document 2). By
reducing the sound output from each speaker, the sound pressure outside the target area can be
reduced. [Patent Document 1] JP-A-61-57197 (page 2-3, FIG. 2) [Patent Document 2] JP-A-8221081 (specification, FIG. 5) SUMMARY OF THE INVENTION However, in the prior art (Patent
Document 1), when realizing a configuration capable of concealing the contents of a call from the
passenger, the parametric speaker requires power consumption, size, Issues remain in terms of
cost, safety, etc., and have not been put to practical use for in-vehicle purposes. In the method
disclosed in Patent Document 2, the head area of the hands-free user, that is, the driver's head
changes depending on the position of the seat and the driving posture when the interior
environment of the vehicle is taken into consideration. Need to be changed. Although a system
for changing the position using a camera or a sensor can be considered, it is necessary to install
these devices for position detection, which causes a problem in cost / space.
Further, since the sound itself from the speaker is not processed, depending on the passenger's
hearing ability, there is a possibility that the content can be grasped by concentrating on a
specific speaker. Therefore, the present invention aims to provide an audio signal transmission
apparatus and method suitable for the purpose of in-vehicle hands-free secrecy. SUMMARY OF
THE INVENTION In order to achieve the above object, according to a first aspect of the present
invention, there is provided an acoustic signal transmission apparatus comprising: sound signals
output from a plurality of speakers in a predetermined target area; It is an acoustic signal
transmission device which has a delay generation part which controls a phase so as to strengthen
each other and which outputs the sound signal from the plurality of speakers, and the target
when the position of the target area changes among the plurality of speakers An output band
control unit is provided to perform control to output a high frequency component of the sound
signal from a speaker with a small change in distance from the area. An acoustic signal
transmission apparatus according to a second aspect of the present invention has a delay
generation unit that controls phases such that sound signals output from a plurality of speakers
in a predetermined target area are strengthened. It is an acoustic signal transmission device that
outputs a sound signal from the plurality of speakers, and when one or more observation points
are installed in the space and the sound signal is output from one of the plurality of speakers, the
sound signal is received at the observation point An output band control unit is provided to
perform band control at a stage prior to the speaker so as to lower the output with respect to the
frequency that becomes strong. An acoustic signal transmission apparatus according to a third
aspect of the present invention includes a delay generation unit that controls phases such that
sound signals output from a plurality of speakers in a predetermined target area are
strengthened. An acoustic signal transmission apparatus that outputs a sound signal from the
plurality of speakers, and adds a superimposed signal having a phase relationship that cancels
out in the target area to the sound signal output from the plurality of speakers. An acoustic signal
09-05-2019
2
transmission apparatus according to a fourth aspect of the present invention has a delay
generation unit that controls phases such that sound signals output from a plurality of speakers
in a predetermined target area strengthen each other, An acoustic signal transmission apparatus
for outputting a sound signal from the plurality of speakers, wherein the sound signal is a divided
sound fragment signal in a time domain, and the sound fragment signal is sequentially output
from one or more of the plurality of speakers. is there. An acoustic signal transmission apparatus
according to a fifth aspect of the present invention is the acoustic signal transmission apparatus
according to the fourth aspect, further comprising: a first sound fragment signal which is an
arbitrary sound fragment signal; A time interval is provided between a fragment signal and a
second sound fragment signal which is a sound fragment signal following the fragment signal.
An acoustic signal transmission apparatus according to a sixth aspect of the present invention is
the acoustic signal transmission apparatus according to any one of the fourth to fifth aspects,
wherein the sound fragment signal is filtered to remove high frequency components. It is.
Further, according to a seventh aspect of the present invention, there is provided an acoustic
signal transmission method according to a seventh aspect of the present invention, from among
the plurality of sound output means, the target area to the sound output means when the
predetermined target area changes. An output band control step of outputting a high frequency
component of the sound signal as a band control sound signal from the sound output means
having a small change in distance; and the band control sound so that the band control sound
signal intensifies in the target area It has a delay generation step of controlling the phase of the
signal, and a sound output step of outputting the band control sound signal from the plurality of
sound output means. In the acoustic signal transmission method according to an eighth aspect of
the present invention, the sound signal outputted by one of the plurality of sound output means
is stronger than the frequency at which the observation point is determined in advance. An
output band control step of outputting a band control sound signal subjected to band control to
reduce an output, and a delay generation step of controlling a phase of the band control sound
signal such that the band control sound signal intensifies in the target area And a sound output
step of outputting the band control sound signal from the plurality of sound output means. In the
acoustic signal transmission method according to a ninth aspect of the present invention, a
superimposed signal having a phase relationship that cancels out in the target area when output
from a plurality of sound output means is added to the sound signal as a synthesized sound
signal, A waveform synthesis step for sending to the plurality of sound output means, a delay
generation step for controlling the phase of the synthesized sound signal so that the synthesized
sound signal overlaps in the target area, and the plurality of sound output means And a sound
output step of outputting. In the acoustic signal transmission method according to claim 10 of
the present invention, the sound signal is used as a divided sound fragment signal at an arbitrary
time interval, and sequentially output to any one or more of a plurality of sound output means. A
sound signal processing step to be performed, a delay generation step of controlling a phase of
the sound fragment signal so that the sound fragment signal is connected in a predetermined
09-05-2019
3
target area, and the sound fragment signal from the plurality of sound output means And a sound
output step of outputting. BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1
Hereinafter, an acoustic signal transmission apparatus according to Embodiment 1 of the present
invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a functional configuration of the acoustic signal transmission
device in the first embodiment. In FIG. 1, 101 is an acoustic signal output unit, 111 is a first
output band control unit, 112 is a first delay generation unit, 113 is a first speaker, 121 is a
second output band control unit, 122 is a second The second delay generating unit, the second
speaker 123, the third output band control unit 131, the third delay generating unit 132, and the
third speaker 133. FIG. 2 is a diagram showing an example of the speaker arrangement in the
present embodiment. FIG. 2 shows the driver's side in the passenger compartment. In FIG. 2, 200
is a driver's seat, 201 is a target area, and 202 is a side glass. The first speaker 113, the second
speaker 123, and the third speaker 133 are respectively installed at the headrest (right side) of
the driver's seat, the position of the driver's seat side door, and the upper part of the driver's seat
side pillar. The operation of the acoustic signal transmission apparatus according to this
embodiment will be described below with reference to FIGS. 1 and 2. In the first embodiment, it
is assumed that the first speaker 113, the second speaker 123, and the third speaker 133 are
sequentially located farther from the target area. When sounds are simultaneously emitted from
the respective speakers, the sounds from the respective speakers arrive in the order of the
sounds from the speakers near the target area. The arrival time difference t12 between the sound
from the first speaker 113 and the sound from the second speaker 123 is the sound velocity V,
the distance from the first speaker 113 to the target area 201 is L1, the second speaker 123 to
the target area 201 Assuming that the distance to the end is L2, it is represented by t12 = (L2L1) / V. Also, the difference in arrival time t13 between the sound from the first speaker 113 and
the sound from the third speaker 133 is t13 = (L3-L1) / V, where L3 is the distance from the
third speaker 133 to the target area 201. Be done. In this case, the delay amount in the first
delay generation unit 112 is 0, the delay amount in the second delay generation unit 122 is t12,
and the delay amount in the third delay generation unit 132 is t13. If it is output, the sounds
output from the respective speakers arrive at the target area 201 at the same time, and there is a
phase relationship in which they are reinforced. By setting the target area 201 to the position of
the right ear of the driver, it is possible to make the driver easy to hear only. In the acoustic
signal transmission device of the first embodiment, the output band control unit outputs different
frequency bands to the sound signals output from the speakers.
In the on-vehicle environment, the position of the right ear of the driver, that is, the target area
changes depending on the position of the seat, the posture of the driver, and the like. Therefore,
in the first embodiment, the sound in the high frequency region from the speaker in a positional
relationship in which the distance relationship between the speaker and the target area does not
09-05-2019
4
change much due to the displacement of the right ear position, and the sound in the low
frequency region from the speaker in the position affected by the displacement. Output The low
frequency sound has a long wavelength, so the amount of phase change with respect to
displacement is small. For example, in the case of sound with a frequency of 340 Hz, one
wavelength is 1 m, and the phase change is relatively small even for a displacement of about 10
cm to 20 cm, and the shift of the phase relationship due to displacement can be suppressed
small. In the first embodiment, since the first speaker 113 is fixed to the sheet, the influence of
the displacement of the sheet is small, so the first output band control unit 112 passes only the
high frequency band, for example, a frequency of 1000 Hz or more. Let The second output band
control unit 122 passes only the sound in the lower frequency band, for example, 500 Hz to
1000 Hz. As for the output sound from the third speaker 133 that is most affected by the
displacement, the third output band control unit 132 passes only the sound with a low
frequency, for example, 500 Hz or less. The outputs from the speakers overlap each other in the
target area 201, and the original sound is reproduced. As described above, by using the acoustic
signal transmission device according to the present embodiment, it is possible to make it easy for
the driver only to hear the sound and to reduce the influence of the driver's head position
displacement in the vehicle compartment. Can be realized. The speaker position, the number of
speakers, the frequency range of each speaker output, and the device configuration in the first
embodiment are an example, and the present invention is not limited to the present embodiment.
Although the delay amount in each delay generation unit is fixed in the first embodiment, the
same effect can be obtained by detecting the sheet position and correcting the delay amount in
each delay generation unit. can get. In this case, the influence of the target area displacement on
the change in the driver's posture can be reduced. Further, in the first embodiment, the target
area is set to the position of the driver's right ear in consideration of the position far from the
assistant driver's seat, but the same method may be applied to the opposite ear position. Is
possible. In the first embodiment, the delay amount in each delay generation unit is set to a value
obtained by dividing the distance difference by the speed of sound. However, a microphone is
installed in the target area, and a test signal is output to actually measure the delay. The amount
may be set in the delay generator.
In addition, in an actual device, it may be necessary to make detailed settings such as different
delay amounts for each frequency. In that case, it can be realized as a configuration in which the
delay amount is changed for each frequency in each delay generation unit. As a method of setting
the delay time, methods shown in JP-A-11-262081 and JP-A-2001-21493 can be shown as an
example. Further, with regard to the positions of the speakers shown in FIG. 2, there is a
difference between the distance between each speaker and the target area, for example, the ear
position at the front passenger seat and the distance difference between the speakers. Need to be
set. That is, the difference between L1 and L2 (L2-L1) is the difference between the distance L1
'from the first speaker 113 to the other listening point and the distance L2' from the second
speaker 123 to the other listening point When it becomes equal to (L2'-L1 '), superposition of
09-05-2019
5
both speaker output sounds occurs at the other listening point as well. In order to avoid this, the
confidential effect can be further enhanced by setting the positions of the speakers in
consideration of the position of the separate listening point. In addition, although the directivity
of the speaker is not mentioned in the first embodiment, the first embodiment is not limited to
the case where the speaker has no directivity, that is, a speaker having the same output
characteristic in all directions. The effects described above can be obtained. In addition, when the
speaker has directivity, the sound pressure difference between the target area 201 and other
points by directing the directivity to the target area 201 can be increased, and the characteristics
can be improved. Second Embodiment Next, an acoustic signal transmission apparatus according
to a second embodiment will be described. In this acoustic signal transmission device, the secrecy
effect is improved by setting the frequency range of the sound output from each speaker to a
range in which the acoustic characteristic in the vehicle compartment is taken into consideration.
The configuration of the acoustic signal transmission device according to the second embodiment
is the same as that of the first embodiment, that is, the configuration of FIG. 1, and therefore the
illustration and the description of the configuration will be omitted. Since the cabin space is a
closed space, standing waves are generated by the influence of reflection. The generation of the
standing wave will be described with reference to FIG. FIG. 3 is a diagram showing the principle
of standing wave generation. In FIG. 3, 300 is a reflective surface, 310 is an incident wave at time
t0, 311 is an incident wave at time t1, 312 is an incident wave at time t2, 320 is a reflected wave
at time t0, and 321 is a reflected wave at time t1. , 322 is a reflected wave at time t2, 330 is a
synthesized wave at time t0, 331 is a synthesized wave at time t1, and 332 is a synthesized wave
at time t2.
In FIG. 3, the horizontal axis indicates the distance, and the vertical axis indicates the amplitude
of each wave. At time t 0, the incident wave 310 and the reflected wave 320 are summed at each
point on the path to form a combined wave 330. For example, when the incident wave 310 and
the reflected wave 320 are added at the point A, they cancel each other out and become zero.
Further, at the point B, as a result of the addition, a high sound pressure as shown in FIG. 3 is
obtained. The same applies to time t1 and time t2. The combined wave at point A has an
amplitude of 0 at each time, as shown in FIG. Also, the composite wave at point B will have a
larger amplitude than the original incident wave. Thus, in an environment affected by reflection,
an amplitude or standing wave occurs at a specific position. Although one reflective surface is
shown in FIG. 3, when there are a plurality of reflective surfaces, this superposition is repeated.
Depending on the shape of the space, the amplitude may be large at a specific position
determined by the wave amplitude and the reflection position. In the second embodiment, at the
time of designing an acoustic signal transmission device, a standing wave in a vehicle interior
generated by each speaker is measured. That is, one or more microphones are installed in the
vehicle interior, white noise which is a sound having flat frequency characteristics is transmitted
from one of the speakers, and the transmission sound is collected by the microphone. As for the
installation position of the microphone, it is assumed that the position of the passenger is around
09-05-2019
6
the position of the ear. The collected sound is subjected to Fourier transform to convert it into
frequency domain data. From the data, it is possible to know the frequency band in which
standing waves are likely to occur for each speaker. When setting a band to be passed in each
output band control unit, setting is performed so that the output is suppressed also for the
frequency band in which the standing wave obtained by the data is likely to occur. In the case of
standing wave measurement in the passenger compartment according to the present
embodiment, a doll imitating the same passenger or the like is installed at the position of the
front passenger seat or the rear seat, and measurement is performed more accurately. It is
possible to identify the place where the wave exists. Further, by detecting whether there is a
passenger in each seat in conjunction with a sensor in the vehicle compartment, and changing
the assigned frequency of each speaker, a higher standing wave suppression effect can be
obtained, and the confidential speech effect can be improved. it can. Third Embodiment Next, an
acoustic signal transmission apparatus according to a third embodiment will be described. In this
acoustic signal transmission apparatus, another sound is added to the sound output from each
speaker, and another sound is canceled in the target area, thereby providing a secrecy effect.
FIG. 4 is a block diagram showing a functional configuration of the acoustic signal transmission
device according to the third embodiment. In FIG. 4, 402 is a superimposed signal generation
unit, 411 is a first waveform synthesis unit, 414 is a first phase control unit, 421 is a second
waveform synthesis unit, 424 is a second phase control unit, 431 is a third And 434 is a third
phase control unit. In the present embodiment, the superimposed signal generated by the
superimposed signal generation unit 402 is superimposed on the output of the acoustic signal
output unit which is the original signal. In the present embodiment, it is assumed that a single
frequency signal is used for explanation. The phase of the superimposed signal is shifted in the
first phase control unit 414, the second phase control unit 424, and the third phase control unit
434, and the first waveform synthesis unit 411, the second waveform synthesis unit 421, and It
is sent to the third waveform synthesis section 431. Each phase control unit shifts the phase so
that the result of adding the superimposed signals is 0 at each time. An example of superimposed
signal phase control in the present embodiment is shown in FIG. In FIG. 5, 500 is a superimposed
signal, 510 is a signal output from the first phase control unit, 520 is a signal output from the
second phase control unit, and 530 is a signal output from the third phase control unit. is there.
In FIG. 5, the horizontal axis represents time, and the vertical axis represents the signal
amplitude. In this embodiment, as shown in FIG. 5, the superimposed signal is a single sine wave
signal, and each output signal is shifted by 2π / 3 radians. The result of superposing the output
signals is 0 at each time. The superimposed signal subjected to the phase control shown in FIG. 5
and the original sound signal are added in the first waveform synthesis unit 411, the second
waveform synthesis unit 421 and the third waveform synthesis unit 431, and As in the first
embodiment, the first delay generation unit 112, the second delay generation unit 122, and the
third delay generation unit 132 add appropriate delays to the first speaker 113, the second
speaker 123, and the third delay generation unit 132. It is outputted from the third speaker 133.
09-05-2019
7
Among the sound signals that have reached the target area 201, the component of the
superimposed signal is canceled as a result of the addition. As a result, the sound heard in the
target area 201 is the original signal output from the acoustic signal output unit 101. At points
other than the target area 201, as a result of the addition of the superimposed signal, there is no
phase relationship to be canceled, so it remains as sound and makes it difficult to hear the
original signal. The speaker position, the number of speakers, the frequency range of each
speaker output, and the device configuration in the third embodiment are merely an example,
and the present invention is not limited to the present embodiment.
In the third embodiment, although the superimposed signal is a sine wave of a single frequency,
the present invention is not limited to this. Any signal may be used as long as the addition result
is 0 in the target area. May be. In addition, with regard to the superimposed signal used in the
third embodiment, by using a sound that is not offensive as much as possible in consideration of
human auditory characteristics, it is possible to suppress the discomfort of the passenger. Fourth
Embodiment Next, an acoustic signal transmission apparatus according to a fourth embodiment
will be described. In this acoustic signal transmission device, the sound output from each speaker
is separated in the time domain and output, thereby providing a secrecy effect. Hereinafter, the
configuration of the acoustic signal transmission device according to the fourth embodiment and
a method of setting each speaker output will be described with reference to the drawings. FIG. 6
is a block diagram showing a functional configuration of the acoustic signal transmission device
according to the fourth embodiment. In FIG. 6, 611 is a first sound signal processing unit, 621 is
a second sound signal processing unit, and 631 is a third sound signal processing unit. In the
fourth embodiment, in order to simplify the description, it is assumed that the distances from the
target area 201 to the speakers (first, second and third speakers) are the same. The first sound
signal processing unit 611, the second sound signal processing unit 621, and the third sound
signal processing unit 631 output the output from the sound signal output unit 101 at certain
time intervals. Hereinafter, the sound signal output will be described with reference to FIG. FIG. 7
is a diagram showing the output sound of each speaker in the present embodiment. In FIG. 7,
700 is a sound signal output from the sound signal output unit 101, 710a, 710b,..., 710j is a
sound signal output from the first speaker at each time interval, 720a, 720b,. Are sound signals
output from the second speaker 123 at each time interval, and 730a, 730b,..., 730j are sound
signals output from the third speaker 133 at each time interval. In the time interval of time t0 to
t1, the first sound signal processing unit 611 outputs a sound signal as indicated by 710a. The
second sound signal processing unit 621 and the third sound signal processing unit 631 do not
output a signal at this time interval. In addition, the second sound signal processing unit 621
outputs a signal as indicated by 720a in a time interval of time t1 to t2, and a sound is output
from the second speaker 123.
In addition, in the time interval between time t2 and t3, the third sound signal processing unit
09-05-2019
8
631 outputs a signal as indicated by 730a, and the third speaker 133 outputs a sound. In the
following, sound output is performed sequentially from each speaker as described above. In the
fourth embodiment, since the distances from the target area 201 to the respective speakers are
equal to each other, the sounds from the respective speakers are seamlessly connected in the
target area 201 and have the same shape as the original sound signal 600. Become. On the other
hand, at other points where the distances to the respective speakers are different from each
other, the transmission delays of the respective speakers are different, so that the waveforms do
not connect seamlessly but partially overlap, which makes it difficult to hear. In the above
description, although the distance from the target area 201 to each speaker is constant, the delay
amount in the first delay generation unit 112, the second delay generation unit 122, and the
third delay generation unit 132 By setting the speakers according to the distance difference as
described in the first embodiment, the same effect can be obtained even when the speakers are
installed at different positions. The speaker position, the number of speakers, the device
configuration, and the like in the fourth embodiment are merely examples, and the present
invention is not limited to the present embodiment. Further, in the fourth embodiment, the sound
output from each speaker is output in order at equal intervals, but the implementation is not
limited to this, and different time intervals may be used. Also, the same effect can be obtained by
dynamically changing the output order / output time. In the fourth embodiment, although the
original signal is separated on the time axis and output as it is, by providing a minute time gap
before and after the speaker switching time, the occurrence of overlapping due to a slight change
in the listening position is realized. It can be suppressed and the ease of hearing in the target
area is improved. In addition, by passing the low-pass filter before output, by smoothing and
outputting the portion of the output waveform edge, it is possible to similarly suppress the
influence of the overlap. The process according to the fourth embodiment can be easily
introduced into a system that digitizes and processes a sound signal. A sound signal which is an
analog signal is separated at fixed time intervals in digitization, subjected to sampling processing
for quantization, and then digitized. The digitized data is subjected to various processes and
finally D / A (digital-analog) converted and output from the speaker. By performing an operation
in which data of time other than the time interval to be output is set to 0 before this D / A
conversion, it is possible to easily obtain a target thinned sound signal.
In each of the first to fourth embodiments, although the case of achieving a confidential story in
the vehicle compartment has been described, the present invention is similarly applicable to an
environment other than the vehicle interior. As described above, according to the acoustic signal
transmission apparatus of the present invention, the delay generation for controlling the phase
such that the sound signals output from the plurality of speakers in a predetermined target area
are strengthened The sound output from the plurality of speakers, the sound from the speaker
having a small change in distance from the target area when the position of the target area
changes among the plurality of speakers By controlling to output the high frequency component
of the signal, it is possible to realize a configuration that makes it easy for the driver only to hear
09-05-2019
9
the sound and to suppress the influence of the displacement of the head position of the driver in
the vehicle compartment. In addition, it has a delay generation unit that controls the phase such
that sound signals output from a plurality of speakers in a predetermined target area are
reinforced, and in the configuration in which the sound signals are output from the plurality of
speakers, When one or more observation points are provided and the sound signal is output from
one of the plurality of speakers, band control is performed in the previous stage of the speaker so
as to lower the output with respect to the frequency at which the sound signal becomes strong at
the observation point Thus, the assigned frequency of each speaker can be changed, the standing
wave can be suppressed, and the secrecy effect can be improved. [0066] Further, in the
configuration having a delay generation unit that controls a phase such that sound signals output
from a plurality of speakers in a predetermined target area strengthen each other, the plurality of
sound signals are output from the plurality of speakers By adding a superimposed signal having
a phase relationship that cancels out in the target area to the sound signal output from the
speaker, there is no phase relationship that is canceled as a result of the superimposed signal
being added at a position other than the driver's ear It can remain as a sound, making it difficult
to hear the original signal and improving the secrecy effect. [0067] Further, in the configuration
having a delay generation unit that controls a phase such that sound signals output from a
plurality of speakers in a predetermined target area strengthen each other, the sound signal is
output from the plurality of speakers By using the signal as a segmenting sound fragment signal
in the time domain and sequentially outputting the sound segment signal from any one or more
of the plurality of speakers, the original sound signal is not seamlessly connected at a position
other than the driver's ear It becomes difficult to listen to each other and it is possible to improve
the secrecy effect.
Further, according to the sound signal transmission method of the present invention, among the
plurality of sound output means, the distance from the target area to the sound output means
when the position of the predetermined target area changes is determined. The high frequency
component of the sound signal is outputted as a band control sound signal from the sound
output means having a small change, and the phase of the band control sound signal is controlled
so that the band control sound signal reinforces each other in the target area; By outputting the
band control sound signal from the plurality of sound output means, it is possible to realize a
configuration that makes it easy for the driver only to hear the sound and to suppress the
influence of the driver's head position displacement in the vehicle compartment. Also, a band
control sound signal subjected to band control so that the output is reduced with respect to the
frequency at which the sound signal output from one of a plurality of sound output means
becomes strong at a predetermined observation point Control the phase of the band control
sound signal so that the band control sound signal intensifies each other in the target area, and
outputs the band control sound signal from the plurality of sound output means, thereby
suppressing the standing wave Can improve the secrecy effect. Further, when output from a
plurality of sound output means, a superimposed signal having a phase relationship which
09-05-2019
10
cancels out in the target area is added to the sound signal to be a synthesized sound signal, and
sent to the plurality of sound output means. The phase of the synthesized sound signal is
controlled so that the synthesized sound signals overlap, and the synthesized sound signal is
output from the plurality of sound output means, whereby the phase canceled as a result of the
addition of the superimposed signal at positions other than the driver's ear Because it is not
related, it remains as a sound, making it difficult to hear the original signal and improving the
secrecy effect. In addition, the sound signal is used as a divided sound fragment signal at an
arbitrary time interval, and is sequentially output to any one or more of a plurality of sound
output means, and the sound fragment is determined in a predetermined target area. By
controlling the phase of the sound fragment signal so that the signals are connected and
outputting the sound fragment signal from the plurality of sound output means, the original
sound signal is not seamlessly connected at a position other than the driver's ear, It becomes
difficult to listen to each other and to improve the secrecy effect. BRIEF DESCRIPTION OF THE
DRAWINGS FIG. 1 is a block diagram showing a functional configuration of an acoustic signal
transmission device according to a first embodiment of the present invention. FIG. 2 is a diagram
showing an example of a speaker arrangement in the first embodiment of the present invention.
FIG. 3 illustrates the principle of standing wave generation. FIG. 4 is a block diagram showing a
functional configuration of an acoustic signal transmission device according to a third
embodiment of the present invention.
FIG. 5 is a diagram showing an example of superimposed signal phase control in a third
embodiment of the present invention. FIG. 6 is a block diagram showing a functional
configuration of an acoustic signal transmission device according to a fourth embodiment of the
present invention. FIG. 7 is a diagram showing the output sound of each speaker in the fourth
embodiment of the present invention. Explanation of the code 101 sound signal output section
111 first output band control section 112 first delay generation section 113 first speaker 121
second output band control section 122 second delay generation section 123 second speaker
131 third output band control unit 132 third delay generation unit 133 third speaker 201 target
area 402 superimposed signal generation unit 411 first waveform synthesis unit 414 first phase
control unit 421 second waveform synthesis unit 424 Second phase control unit 431 Third
waveform synthesis unit 434 Third phase control unit 611 First sound signal processing unit
621 Second sound signal processing unit 631 Third sound signal processing unit
09-05-2019
11
Документ
Категория
Без категории
Просмотров
0
Размер файла
27 Кб
Теги
jp2004112528
1/--страниц
Пожаловаться на содержимое документа