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The present invention relates to a voice sounds transmitting and receiving
apparatus suitable for use under noisy circumstances and having a
microphone and a speaker to which a new and useful improvement is added.
For the purpose of transmitting voice sounds at places such as a coal
mining site, air port and constructural site, there have been
conventionally used a method of using a unidirectional microphone
immediately before the lips of a user and a method of attaching a
vibration pick-up of the acceleration type to the throat or the forehead
of the user. However, the former has such a limitation that the
unidirectional microphone can not eliminate environmental noises
completely, thus being unsuitable for use under extremely noisy
circumstances. On the other hand, the latter makes it necessary to attach
the vibration pick-up to the throat or the forehead of the user and the
attaching operation is complicated and troublesome. In addition, the user
feels discomfort with the pick-up being attached to him, thus resulting in
that the user can not wear the pick-up for a long time.
There is also well known a method of using the changes in the sound
pressure in the ear canal of the user which occur when he utters voice
sounds. However, these conventional methods are carried out by attaching a
microphone into his ear and an earphone into his other ear or by carrying
in his hand and pressing to one of his ears a device having the microphone
and the earphone incorporated therein, thus resulting in such
disadvantages that environmental sounds can not reach his ear drum to
thereby put him in a dangerous state as his both ears are closed by the
earphone and the microphone and his both hands can not be freely used when
the hand-carrying device is used.
When the microphone and the earphone arranged to use the changes in the
sound pressure in the ear canal are used in these conventional voice
sounds transmitting and receiving apparatus of the above-mentioned type,
the voice sound generated from the voice sounds receiving system are fed
back to the microphone of the voice sound transmitting system, thus
causing a so called howling.
Further, these voice sounds transmitting and reciving apparatus arranged to
use the changes in the sound pressure in the ear canal have been
disadvantageous in that the voice sounds of a low frequency band are
emphasized by closing the external auditory canal, thus causing the
clarity of the voice sounds to be degraded.
Though the voice sounds having a high clarity can be obtained only by
correcting the hearing ability of the user according to the A
characteristic or according to the hearing characteristic of the user,
there will unavoidably occur the above-mentioned howling phenomenon unless
the changeover from voice sounds transmitting operation to voice sounds
receiving operation and versa is attained.
The present invention is intended to eliminate the above-mentioned
disadvantages inherent to conventional voice sound transmitting and
receiving apparatus.
Accordingly, a primary object of the present invention is to provide a
voice sound transmitting apparatus through which the voice sound
transmitting operation can be attained without being influenced by any
environmental noises.
Still further object of the present invention is to provide a voice sound
transmitting apparatus which is designed to pick up the voice sound
through the external auditory canal wall by means of a vibration pick-up
capable of completely eliminating the evironmental noises, which is easily
attached to the user, which has a fine appearance, and which gives the
user no discomfort when the apparatus is used for a long time.
Still further object of the present invention is to provide a voice sound
transmitting apparatus designed to pick up the voice sound of high clarity
from the vibrations transmitted through the external auditory canal wall
of the user.
A still further object of the present invention is to provide a voice sound
transmitting apparatus wherein a vibration pick-up is provided in an
earpiece which is inserted into the external auditory canal so as to pick
up the voice sounds effectively.
These and other objects of the present invention will be apparent from the
following detailed description of embodiments of the present invention
with reference to the accompanying drawings.
FIG. 1 is a section showing a first embodiment of the present invention.
FIG. 2 is a section taken along the line II--II in FIG. 1.
FIG. 3 is a view, partly sectioned, showing how the first embodiment is
used.
FIG. 4 is a block diagram showing a second embodiment of the present
invention.
FIG. 5 is a section showing a pick-up of the acceleration type which is a
third embodiment of the present invention.
FIG. 6 is a section taken along the line IV--IV in FIG. 5.
FIGS. 7 and 9 are sections showing modifications of a pick-up according to
a third embodiment of the present invention.
FIG. 8 is a section taken along the line VIII--VIII in FIG. 7.
FIG. 10 is a section showing another example of the pick-up of acceleration
type.
FIG. 11 is a section showing a fourth embodiment of the present invention.
FIG. 12 is an enlarged section showing a fifth embodiment of the present
invention.
FIGS. 13 and 14 are elarged isometric views showing how the piezo elements
are located.
FIG. 15 is an elarged isometric view showing another example of the piezo
element.
FIG. 16 is an enlarged view, partly sectioned, showing a sixth embodiment
of the present invention.
FIG. 17 is a graph showing the frequency characteristic of the embodiment
in FIG. 16.
FIG. 18 is an enlarged section showing the head portion of the vibration
pick-up.
FIGS. 19 through 22 are enlarged sections showing some modifications of the
head portion of the vibration pick-up.
FIG. 23 is a section showing an eighth embodiment of the present invention.
FIGS. 24 and 26 are enlarged sections showing a ninth embodiment of the
present invention.
FIG. 25 is an enlarged section taken along the line XXIV--XXIV in FIG. 24.
FIG. 27 is an enlarged section showing a tenth embodiment of the present
invention.
FIG. 28 is an enlarged section showing an eleventh embodiment of the
present invention.
FIGS. 29 through 31 show a twelfth embodiment of the present invention in
which FIG. 29 is a section thereof and FIGS. 30 and 31 are front views
showing an ear muff.
FIGS. 32 and 33 are partly enlarged sections showing a thirteenth
embodiment.
FIG. 34 is a section showing a fourteenth embodiment of the present
invention.
FIG. 35 is an enlarged section showing a fifteenth embodiment of the
present invention.
EMBODIMENT 1
FIGS. 1 and 2 show a typical arrangement of the first embodiment arranged
to use the changes in the sound pressure in the ear canal. In FIGS. 1 and
2, numeral 1 represents an earpiece closely inserted into the external
auditory canal 2 and numeral 3 a hollow portion provided within the
earpiece 1, said hollow portion 3 communicating with the space in the ear
canal 2 through an aperture 4 provided in the side of the earpiece 1
facing the ear drum. Numerals 5 and 6 represents super mini-sized a
microphone and earphone, respectively, secured in the hollow portion 3 and
the vibration diaphrams 5' and 6' thereof are in contact with the air in
the canal. The super mini-sized microphones suitable for use in this
embodiment are, for example, those of the condenser type and of the
electlet condenser type. The microphone and the earphone can be arranged
in various ways and it is typical that they are arranged in the hollow
portion of the earpiece which is in communication with the air in the ear
canal through the aperture. It is not important how they are located with
relative to each other in the hollow portion of the earpiece.
FIG. 3 shows how the first embodiment is used. In this case an electrical
circuit 8 including a transmitting and receiving means may be attached to
a soundproofing cover member 9 such as an ear muff which is intended to
block the environmental noises, a safety helmet, a cap or the line. When
an antenna 10 is used, it may be also attached to the soundproofing cover
member 9, the safety helmet, the cap or the like. It is desirable that the
earpiece 1 is formed corresponding to the outline of the external auditory
canal and to the recess portion of the ear canal, so that the earpiece
thus formed will not result in discomfort to the user even if it is used
for a long time.
In this embodiment it is possible to obtain the voice sounds of extremely
high clarity by attaching an equalizer to the microphone so as to improve
hearing ability of the user according to the a characteristic and the
voice and characteristic of the user.
The microphone and the earphone of this embodiment are arranged to use the
changes in the sound pressure in the ear canal and are fixed in the
external auditory canal of an ear. Accordingly, the user can use both his
hands freely for any purposes while speaking. Further, the other ear of
the user is open to the outside or covered only by the ear muff or the
like, so that he can hear any environmental sound thereby avoiding any
danger which may occur when both of his ears are closed. Furthermore, the
microphone and the earphone are arranged in the earpiece which is closely
inserted into the external auditory canal so that reduction of the
environmental noises to a degree of 20 dB can be expected in the ear
canal. Still further, the ear muff or the like can be used integral with
the apparatus so that further reduction of the environmental noises to a
degree of 20dB can be expected in this case. Therefore, the embodiment is
suitable for use under a noisy environment, particularly when both hands
of the user are required to do a job under noisy conditions.
There has been conventionally well known a method of transmitting the voice
sounds by using the changes in the sound pressure in the ear canal of the
user when he utters voice sounds, but the ear microphone used in this case
has some problems. One of them relates to its frequency characteristic,
another to its principle and the other to the degradation of its
sensitivity. Namely, they are that since the ear microphone is intended to
pick up the voice sounds transmitted through the bones, its frequency
characteristic is limited to the frequency band of 100-2,000 Hz and that
the ear microphone functions to emphasize the low frequency components due
to the blockage of the external auditery canal so that it is necessary to
add a mechanical and electrical correction to the earmicrophone, thereby
causing the sensitivity of the microphone to be degraded. This
conventional ear microphone is designed to use the changes in the sound
pressure in the ear canal of the user and, therefore, the S/N ratio
relative to the environmental noises can be enhanced to a degree of about
30 dB when the earmicrophone is used under a normal circumstance. However,
the sound pressure in the external auditory canal is about -15 dB in the
case of using the earmicrophone and, therefore, the real enhancement of
the S/N ratio comes to be about 15 dB, thus making it necessary to
eliminate the environmental noises by a different way when this
earmicrophone is used under noisy conditions. To add further, the
environmental noises normally include frequency components concentrated in
the low frequency band.
With regard to the quality of the voice sounds, frequency components which
range substantially in a wide frequency band are required in the
transmission of natural voice sounds, particularly, those of a range in a
high frequency band are essential to the transmission of natural voice
sounds having a clarity as regard pronouncing consonants. Accordingly, the
ear-microphone having a limitation in its frequency component is not
satisfactory.
When the voice sounds are heard by a person who utters them, the frequency
components in the low frequency band are almost the sounds transmitted
through the bones and the frequecy components in the high frequency band
are almost the air conductive sounds uttered through the lips.
Considering the above-mentioned matters. the microphone in the first
embodiment of the present invention comprises a combination of the
earmicrophone intended for the frequency components in the low frequency
band and the well-known lip microphone intended for the frequency
components in the high frequency band. Therefore, the enhancement of the
S/N ratio relative to the environmental noises as well as the improvement
of the quality of the voice sounds can be attained by the first
embodiment.
A description has been made mainly to the speaker and the microphone in
this first embodiment, but the voice sounds transmitting and receiving
apparatus including the speaker and the microphone further includes an
electrical circuit, a voice sounds transmitting and receiving means or
others. Therefore, it is desirable that the electrical circuit portion and
the others are contained in a portable case connected to the microphone
through a cord. This can be achieved similarly to the embodiments to be
described.
EMBODIMENT 2
The second embodiment which will be described with reference to FIG. 4 is
intended to obtain voice sounds of high clarity by using the frequency
components of the voice sounds in the ear canal.
Generally speaking, the frequency of the voice sounds uttered by a Japanese
man ranges in the frequency band of 100-5,000 Hz while for a Japanese
woman it is in the frequency band of 180-9,000 Hz. And it is also
recognized that this frequency by a Japanese man basically averages in the
frequency band of 100-130 Hz and that for a Japanese woman in the
frequency band of 180-220 Hz.
Accordingly, in the voice sounds transmitting and receiving apparatus
having the microphone and earphone inserted into the ear canal or
communicated with the space in the ear canal through a communication pipe,
it is arranged so that the output signals from the receiving means are not
applied direct to the earphone but rather after they are passed through a
high-pass filter so as to remove the frequency components including the
basically average ones lower than a specific one (for example, 300 Hz). As
a result the frequency components of the voice signals applied, as inputs,
to the microphone and lower than the specific one contain only the voice
sounds uttered by the user. Thus, it may be arranged that the output
signals from the microphone are passed through the band-pass filter, which
allows only the voice sounds having the frequency components (for example,
100-250 Hz) lower than the specific one to pass therethrough, to be
applied, as input signals, to an automatic changeover switch capable of
rendering the transmitting and the receiving systems in "On" and "OFF"
states and that the outputs from the microphone are introduced to the
transmitting means without passing through the band-pass filter at the
time when the transmitting system is operated.
In FIG. 4, numeral 11 denotes a microphone of the condenser type which is
flat in the frequency band of 50-10,000 Hz and 12 an earphone arranged
intergral with the microphone 11 in an earpiece 23 and communicating with
the air in the ear canal. Numeral 13 represents a receiving means whose
output is amplified by an amplifyer 17 and applied to the earphone 12
through a high-pass filter 14, which allows the voice signals only in the
frequency band of 300-5,000 Hz to pass therethrough, and a switch SW1. On
the other hand, the output signals of the microphone 11 responding to the
changes in the sound pressure in the ear canal are applied, as inputs, to
an oscillator 15 through an amplifier 17' and a switch SW2. The output
signals from the amplifier 17' are applied to an integrator 18 through a
band-pass filter 16 which allows the output signals in the frequency band
of 100-250 Hz to pass therethrough and is converted to voltages by the
integrator 18 to be applied as inputs to a comparator l9. There is also
applied to the comparator 19 the voltages from a reference voltage
generator 20 which are to be compared with the former ones. For outputs of
the comparator 19 are introduced to a switching circuit 21 which causes
the switches SW1 and SW2 to be operated.
The switches SW1 and SW2 may be formed as a release switch or as a
semi-conductor switching circuit including a combination of transistors
and the switches. In FIG. 4 numeral 24 represents an external auditory
canal, A a receiving system, B a transmitting system and C a switch
control section.
The changeover from the transmitting operation to the reciving operation
and vice versa is accomplished as follows: The output voltages of the
integrator 18 are applied, as inputs, to the comparator 19 in which these
inputs are compared with the other predetermined reference output voltages
from the reference voltage generator 20; when the output voltages from the
integrator 18 are higher than those from the reference voltage generator
20, the switching circuit 21 are rendered operative so as to put the
switch SW2 in an "OFF" state and the switch SW1 in an "ON" state; when the
output voltages from the integrator 18 are lower than those from the
reference voltage generator 20, the switching circuit 21 is rendered
operative so as to put the switch SW1 in an "OFF" state and the switch SW2
in an "ON" state.
Accordingly, for example, in case the frequencies applied to the band-pass
filter 16 are whithin the specific frequency band of the band-pass filter
16 (for example, in the frequency band of 100-250 Hz) the output voltages
from the integrator 18 are arranged to be higher than those from the
reference voltage generator 20 and in case the frequencies are over the
specific frequency band of the band-pass filter 16 (for example, in the
frequency band of 300 Hz) the output voltages from the integrator are
arranged to be lower than those from the reference voltage generator, it
will be possible that the voice transmitting system is automatically
operated only when the voice sounds are uttered by the user himself.
The provision of the equalizor in the transmitting system for the purpose
of improving the hearing ability of the user according to the A
characterstic and the voice sound characteristic of the user makes it
possible to obtain voice sounds of high clarity.
More particularly, the microphone of condenser type which is flat in the
frequency band of 50-10,000 Hz is used as an earmicrophone inserted into
the external auditory canal or communicated with the air in the ear canal
through a commuication pipe and, after the output signals of the
earmicrophone are modified by the equalizor to those corresponding to the
A characteristic and the voice sound characteristic of the user, those
modified output signals are applied, as inputs, to the band-pass filter
which allows the low frequency components in the frequency band of
50-2,000 Hz to pass therethrough. On the other hand, the output signals of
the unidirectional microphone (for example, a microphone of the condenser
type which is flat in the frequency band of 50-10,000 Hz) arranged
immediately before the lips of the user are applied, as inputs, to the
high-pass filter which allows the high frequency components in the
frequency band of 2,000-6,000 Hz to pass therethrough. The output signals
from both the band-pass filter and the high-pass filter are applied, as
inputs, to a level regulating section to regulate the level and, after
then, they are applied, as inputs, to the oscillator to be transmitted.
Therefore, since the low frequency components of the transmitted signals
ranged in the frequency band of 50-2,000 Hz are picked up from the changes
in the sound pressure in the ear canal of the user, these components
include few environmental noises but only the voice sounds of the user. In
addition, these components inlude high a frequency band of 2,000-6,000 Hz
which are picked up through the lip microphone. Accordingly, voice sounds
of high quality similar to the natural voice sounds and having a clarity
in consonat pronouncing can be obtained and the environmental noises
included in these high frequency components can be disregarded because the
normal noises include their energy concentrated in the low frequency band.
Therefore, when the present invention is used for telephone service, the
environmental noises included in these high frequency components can be
completely desregarded because the environmental noises consist of mostly
low frequency components.
EMBODIMENT 3
The third embodiment of the present invention is intended to pick up, as
the voice signals, the vibrations of the external auditory canal wall at
the time of uttering the voice sounds.
There will now be described a pick-up constructed as a vibration pick-up of
the acceleration type according to FIGS. 5 and 6. A piezo element 25 is
arranged in an earpiece 27, which is inserted into the external auditory
canal 26 of the user, in such a manner that the operative direction of the
piezo element 25 is substantially perpendicular to the longitudinal
direction of the external auditory canal 26. Pick-up cords 28 extend
outside and are connected to an amplifier (not shown). This amplifier may
be provided in the earpiece 27. The earpiece 27 is formed so as to
correspond to the outline of the external auditory canal and to closely
contact the bone 29 for transmitting the voice sounds and is made of
metal, hard synthetic resin or the like which is capable of transmitting
the vibrations of the bones. The piezo element 25 having a weight 31
mounted on the front end thereof is secured in the earpiece 27 by means of
springs 30.
There will now be described a pick-up formed as a vibration pick-up of the
displacement type. In FIGS. 7 through 9, a piezo element 32 is fixed by a
supporting member 33 at the base thereof, said supporting member 33 being
provided in an earpiece 27 which is made of soft synthetic resin such as
silicone resin or rubber having difficulty in transmitting the vibration,
and to the front end of the earpiece 27 is attached a vibration
transmitting member 34 contact closely contacts the external auditory
canal wall and which composes a part of the earpiece 27. The vibration
transmitting member 34 may be provided at both sides of the piezo element
as shown in FIG. 9.
In the embodiment shown in FIGS. 5 and 6 the earpiece 27 is inserted into
the external auditory canal 26. When the user utters voice sounds, they
reach the voice sounds transmitting bones to vibrate the external auditory
canal. The weight 31 adds to the piezo element 25 a force proportional to
the acceleration speed of the vibration to generate a voltage proportional
to the force added to the piezo element and the voltage is amplified by
the amplifier connected through the pick-up cords 28 to be transmitted
outside.
The embodiment shown in FIGS. 7 and 9 is used and operated similar to that
shown in FIGS. 5 and 6, wherein the vibration is applied to the piezo
element 32 through the vibration transmitting member 34.
In the pick-up shown in FIGS. 7 through 9 the amplifier may be arranged in
the earpiece or the transmitting means may be provided in the earpiece.
The air-coupled earphone may be arranged in the earpiece or may be
connected integral with the earpiece, permitting an interactional
communication to be attained.
The present invention has been described with reference to the pick-ups of
the acceleration type arranged to use the piezo element and of a
modification thereof. Other pick-ups which can be used in the present
invention are as follows:
(1) Magnetic type: Contrary to the speaker, a coil is placed in the
magnetic field and vibrated so as to generate current responding to the
vibration of the coil. The ones belonging to this type are a moving coil
type, a moving magnet type, an induced magnet type, a moving iron type and
a variable reluctance type. The moving coil type is arranged so that the
vibration of the vibration transmitting member contacted with the external
suditory canal wall is transmitted to the coil to generate a voltage. The
moving magnet type is arranged so that the coil is fixed and the magnet is
vibrated. The induced magnet type is a modification of the moving magnet
type and is arranged so that both of the magnet and the coil are fixed and
iron strip is vibrated integral with the vibration transmitting members so
as to change the magnetic force across the coil. The moving iron type is a
modification of the induced magnet type. The variable reluctance type is
so arranged that the vibration transmitting member is placed in the
magnetic field so as to change the magnetic field by the vibration of the
member and to cause the coil near the field to generate current.
(2) Piezo element type: Except the above-mentioned ceramic types there can
be used two piezo elements of the crystal type using potassium sodium
tartrate.
(3) Electret condenser type: This is same in principle as that of the
condenser type, but an electret elecrified semi-permanently when once
charged can be used in the form of a combination with the equalizer in the
present invention.
(4) IC type: A cartridge including an IC circuit is arranged in the
earpiece. The method of generating current in this IC type is the same as
that of the ceramic types.
(5) Semi-conductor type: Instead of the piezo element described in the
above-mentioned embodiments there is used a silicone semi-conductor. To
the silicone semi-conductor is added pressure and the change in the
resistance value in the semi-conductor is derived outside through the
pick-up cords.
When the piezo element is arranged in the earpiece in the present
invention, it is necessary that the operative direction of the piezo
element is substantially perpendicular to the direction at which the
external auditory canal is extending.
It is not necessary that the space in the external auditory canal is
blocked from the outside by means of the earpiece and it is rather
desirable that air escaping aperture 35 and 36 are provided in the
earpiece as shown in FIG. 10 so as to allow the air in the space in the
external auditory canal to escape and to reduce the effect of blocking the
external auditory canal.
It is further desirable that the air escaping aperture 35 is constructed in
such a manner that the sounds from the outside can be blocked and reduced.
Namely, a sound absorbing material may be attached along the aperture or
an expansion chamber 37 may be provided in the way of the aperture so as
to reduce the energy included in the environmental noises and to efface
the noises of low frequency band in the chamber, or a combination of the
sound absorbing material and the expansion chamber may be used so as to
efface the noises of all frequency bands.
EMBODIMENT 4
The fourth embodiment is a combination of a speaker and the vibration
pick-up which was described in the third embodiment. As shown in FIG. 11,
an earpiece 27 is combined with an earphone, which include a speaker
therein and which is in communication with the hollow space of the
earpiece through aperture 39. The hollow space in the earpiece is further
in communication with the space in the external auditory canal through a
broken-away portion 40 provided at the front end of the earpiece. Any
speakers constructed to be of the air-coupled type can be used in the
present invention, but it is desirable that it is made to block the
vibration of the vibration plate of the speaker from the piezo element.
Alternately, the speaker may be located at any place in the air escaping
passage 35 shown in FIG. 10.
EMBODIMENT 5
There will be now described a further improved vibration pick-up according
to FIG. 12. In FIG. 12 numeral 41 represents a cylindrical vibration
transmitting member made of metal or other material capable of
transmitting vibration, 42 a head portion for picking up the vibration
transmitted through the bones in the external auditory canal, said head
portion being attached to the end of the vibration transmitting member 41
and disposed in the external auditory canal wall, 43 a piezo element
secured in the vibration transmitting member 41 through a supporting
member 44 made of a material capable of transmitting the vibration, 45 a
weight fixed to the front end of the piezo element, 46 lead lines, 47 an
impedance transformer circuit, 48 a cord, 49 a metal earth, 50 a cover
made of synthetic resin or rubber and 51 a mold element.
The characteristic of the piezo element 43 has a relation to the vibration
direction thereof and therefore some consideration must be paid to the
characteristic. It has been found that this piezo element has the
following disadvantages because of its arrangement comprising a piezo
crystal plate of zirconic acid and titanium acid lead sandwiched between
two plates of ceramic or the like.
Namely, the results obtained by measuring the outputs of the earmicrophone
by means of a vibration accelerator showed that there was a difference of
about 8 dB in the vibration amplitudes when comparing the case where the
piezo crystal plate was arranged perpendicular to the external auditory
canal wall with the case where it was arranged horizontal to the external
auditory canal wall. This means that the vibration amplitude of the piezo
crystal plate is different depending on the direction at which the plate
is inserted into the external auditory canal and what portion of the
external auditory canal wall vibrates. Therefore, it has been found that
the voice signals transmitted through the bones can not be picked up by
the uniform vibration amplitude of the piezo crystal plate.
According to studies conducted, it has been clarified that the voice
signals (or the vibrations) of the user are transmitted through the side
head bones to the external auditory canal wall and that the portion of the
external auditory canal wall to which the voice signals are transmitted is
generally located, in a case of an adult, at a depth of 10cm from the
entrance of the external auditory canal where the bones capable of
transmitting the vibrations transmitted through the side head bones are
present. Therefore, the portion of the external auditory canal wall to
which the voice signals are transmitted through the bones are different
according to every individual and the pick-up sensitivity sometimes become
worse depending on the direction at which the piezo crystal plate in the
earmicrophone is inserted into the external auditory crystal. Accordingly,
in the embodiment shown in FIG. 12 there is used the same piezo element as
those already described, but the characteristic of the piezo element which
is influenced by the direction at which the vibration pick-up is inserted
into the external auditory canal is improved by using plural piezo
elements 43a and 43a which are different in the angles at which they are
arranged as shown in FIGS. 13 and 14, or there is used a piezo element
comprising a piezo crystal such as zirconic acid titanium acid lead into a
ring shape and covering the outer and the inner surfaces of the
ring-shaped piezo crystal 44a directly or through a reinforcing metal with
polarization members 44b and 44c such as ceramic material.
The function of the piezo element used in this embodiment is the same as
those of the embodiments already discribed.
EMBODIMENT 6
This embodiment is intended to lower the peak of the frequency
characteristic of the microphone used in the external auditory canal and
to obtain the voice signals of high clarity through the bone in the
external auditory canal. As shown in FIG. 16, a head portion 42 disposed
in the external auditory canal wall is arranged to be covered by dumper
member 45 made of rubber, soft synthetic resin or the like. When the
dumper member 45 is present between the head section 42 and the external
auditory canal wall, the peak of the frequency characteristic of the
microphone is lowered and modified as shown in dotted line in FIG. 17,
thus permitting the voice sounds (vibrations) of high clarity through the
bones to be picked up. The head section 42 in FIG. 18 is partly broken
away in such a manner that the sensing outer peripheries Q of the head
portion in the same direction as the sensing direction (P direction) of
the piezo element are urged to the external auditory canal wall. Namely,
the other outer periphries R of the head portion corresponding to the
non-sensing direction of the element are arranged not to be contacted or
to be contacted with the external auditory canal wall more lightly than
the sensing outer peripheries. The shape of this sensing portion may be
formed as a cylindrical one partly broken away, or two sensing portions
being circular in their ends may be projected in the same direction as the
sensing one of the element or other forms may be considered.
EMBODIMENT 7
As shown in FIGS. 19 through 22, this embodiment is intended to function as
a microphone wherein plural head portions 42 different in their outer
diameter having a connection means with a vibration transmitting member
41, respectively, are arranged to be detachable from the vibration
transmitting member and therefore even if the inner diameters of the
external auditory canals of the users are different, the vibration of the
external auditory canall wall can always be picked up so as to attain an
excellent pick-up effect.
EMBODIMENT 8
This embodiment shown in FIG. 23 is a receiver of the bone conductive type
or a hearing aid arranged to transmit the vibrations direct to the bones
of the head.
In FIG. 23 there is provided in a case body 46 and a transducer 47 for
converting the voice sounds to mechanical vibrations. The transducer 47
comprises a magnet 48, an iron core 50 located opposite to the magnet 48
and supported by a dumper 49, a coil 51 wound around the iron core 50 in
series and lead lines 52a connected to the coil 51 and supplying the voice
signal from the outside. The voice signal supplied to the coil 51 render
the iron core 50 excited. In this embodiment there is provided a a
vibration element 52 of the magnetic type which responds to the action of
the magnetic field in the iron core 50 and the vibraions are transmitted
to the external auditory canal wall by inserting the vibration element
into the external auditory canal to closely contact the external auditory
canal wall. It may be arranged that an aperture is provided in the body 46
so as to allow the vibration element 52 to be freely vibrated and to
enhance the vibration reliability of the vibration element. Further, the
vibration element 52 may be provided with an air escaping aperture for
preventing the effect of the external auditory canal blockage.
EMBODIMENT 9
The embodiment shown in FIGS. 24 and 25 is a combination of a transmitting
system and a receiving system, said transmitting system including a
transducer for converting the sound signals to the vibrations such as a
piezo element or the like provide in a vibration transmitting member which
is urged to a portion of the user and to which the voice signals are
transmitted through the bones of the user, and receiving system including
a transducer for converting the sound signals received from the outside to
the mechanical vibrations and a vibration transmitting member for
transmitting the vibrations from the transducer to a portion of the user.
In FIGS. 24 and 25 numeral 54 represents a transducer for converting the
sound signals into the vibrations, said transducer comprising a magnet 56
fixed to a case body 55, an iron core 57 arranged opposite to the magnet,
and a coil 58 wound around the iron core. In this case the iron core may
be fixed while the magnet is movable. Numeral 59 represents wires which
are connected to the coil 58 and supply the sound signals from the
outside. There is provided a vibration transmitting member 60 consisting
of the vibration element of the magnetic type which reponds to the
magnetic field generated in the iron core 57 and said member 60 is
arranged to closely contact the external auditory canal wall. In the
Figures numeral 61 denotes a dumper. The transducer for converting the
vibrations to the sound signals used in the transmitting system has the
same arrangement as that of the vibration pick-up.
The embodiment as shown in FIG. 26 serves to function as the vibration
transmitting member in the transmitting system and the vibration
transmitting member (or vibration element) in the receiving system and the
members shown in FIG. 26 are denoted by same numerals as those in FIGS. 24
and 25.
EMBODIMENT 10
This embodiment shown in FIG. 27 is arranged so that the transmitting
system is located in the external auditory canal and the receiving system
is attached to a portion near the ear, for example, the mastoid cell
behind the auricle, the cheekbone or the jaw. The connection portion 64
between the case 62 including the transmitting system and the case 63
including the receiving system is arranged to have resiliency and the same
numerals are used in FIG. 27 as those in the embodiment already described.
EMBODIMENT 11
The embodiment shown in FIG. 28 is so arranged that the voice sounds
transmitting and receiving means are attached to a portion of the user
capable of transmitting the sound signals through the bones thereof, for
example, the forehead, the throat, the nose bridge, the auricle, the
cheekbones, the jaw or the back of the head, by means of a band 65. There
are used in FIG. 28 same numerals as those in the embodiments of 9 and 10.
In the embodiments shown in FIGS. 9 through 11 the equalizer, the
amplifier, the power source, the transmitter and the receiver may be
contained for a case in both of the transmitting and the receiving systems
or in another form of case capable of being contained in a pocket of the
user.
The embodiments shown in FIG. 9 through 11 having the arrangement as
described above will be described. The function of the transmitting system
is the same as already described. On the other hand, the function of the
receiving system is that the voice signals (or sound signals) transmitted
from the outside are supplied through cords 59 to coils 58 to excite an
iron core 57 and are converted to the mechanical v | | |
