An electropalatograph for speech training and the like, which electrically detects linguapalatal contact mode during phonations by means of many contact sensing electrodes provided on a surface with which trainee's tongue contacts of artificial palate device mounted to hard palate surface of the trainee, detected informations denoting the contact mode are transmitted as electromagnetic waves from a transmitter disposed within the trainee's mouth, and transmitted waves are received by a receiver disposed outside the trainee's body and displayed to be observed as dynamic patterns of actual linguapalatal contact mode.

This invention relates generally to electropalatographs for articulation 
study, speech training and the like and, more particularly, to 
improvements in the electropalatograph wherein an artificial palate having 
many sensing electrodes on the surface with which a trainee's tongue 
contacts when fitted to hard palate surface of the trainee and, during his 
phonations, such actual linguapalatal contact mode is electrically 
detected and, generally, the detected mode is observably displayed on a 
display device so that the trainee's articulation study and correct speech 
training can be accomplished while observing dynamic patterns of the 
actual contact mode. 
Conventionally, in performing the articulation and speech training using 
the electropalatograph of the kind referred to, as seen in FIG. 1, an 
artificial palate device 101 provided with many sensing electrodes is 
fitted intimately to the hard palate surface of a trainee, many lead wires 
connected to the respective sensing electrodes are divided into two right 
and left bundles and these bundles are extended in the form of two cords 
102 and 103 along outside the tooth rows of the trainee from the rear or 
innermost end edge of the artificial palate device 101, respectively 
pulled out of the mouth from both right and left ends of the mouth and 
connected directly or after being once hung on the ears to an 
electropalatograph display device 104. Generally, in the artificial palate 
device 101, in order to accurately obtain the linguapalatal contact 
pattern, 64 sensing electrodes distributed substantially all over the 
tongue contacting surface of the artificial palate are used and each of 
the lead wire cords 102 and 103 includes 32 insulation-coated lead wires 
and becomes comparatively thick. Therefore, the trainee must make the 
phonation or speech while having these two cords positioned at both ends 
of the mouth so that the conventional electropalatograph has had to 
involve such defects that the trainee must be trained while always having 
unpleasant or unnatural feeling due to such cords, some phonations being 
difficult to be correctly performed because of the cords, and saliva in 
the mouth flowing out along the cords so as to hinder the phonations and 
cause a sanitation problem. The present invention has been suggested in 
view of these defects of the conventional electropalatographs. 
A primary object of the present invention is, therefore, to provide an 
electropalatograph which allows articulation and speech trainees to 
perform natural phonations or speeches without having any unnatural 
feeling during the use. 
Another object of the present invention is to provide an electropalatograph 
which employs no element obstructing all kinds of phonations required for 
the articulation and speech training. 
A related object of the present invention is to provide an 
electropalatograph which allows the trainees to perform natural phonations 
or speeches without using lead wire cords pulled out of the mouth through 
both end portions of the lips of the trainee and linguapalatal contact 
modes can be accurately detected.

While the present invention shall be detailed with reference to the 
illustrated embodiment, the intention is not to limit the invention only 
to the specific embodiment shown but rather to include all modifications, 
alterations and equivalent arrangements possible within the scope of 
appended claims. 
Referring to the preferred embodiment of the present invention with 
reference to FIG. 2, an artificial palate device P fitted in close contact 
with the hard palate surface within the mouth cavity of a trainee has a 
plurality of sensing electrodes with their sensing surface exposed on one 
surface of the device with which the trainee's tongue contacts, a 
plurality of lead wires respectively connected at one end to each of the 
sensing electrodes are divided into two right and left cords according to 
distributed positions of the electrodes and the cords are respectively led 
out of the device P and connected to each of a pair of tongue-contact 
signal transmitters T.sub.1 and T.sub.2 of the later described formation. 
The respective transmitters T.sub.1 and T.sub.2 are formed of small 
circuit elements so as to be of a very compact size as a whole and are 
positioned respectively between the right and left inner teeth and the 
cheeks with the respective cords passed behind the innermost ends of the 
upper tooth rows. On the other hand, a pair of receivers R.sub.1 and 
R.sub.2 receiving tongue-contact signals transmitted from the transmitters 
T.sub.1 and T.sub.2 are set by proper means preferably in positions 
adjacent the transmitters but outside the body of the trainee, the 
received signals are sent to a display device D through respective cords 
C.sub.1 and C.sub.2. The device D displays the detected linguapalatal 
contact mode in its dynamic pattern upon actual phonation or speech of the 
trainee in response to the tongue-contact signals. 
A practical example of the formation of the transmitters T.sub.1 and 
T.sub.2 employed in this embodiment shall be described with reference to 
FIG. 3. In the present instance, the artificial palate device P has a 
signal electrode S connected with a signal source 12 and provided on the 
surface of the device to be brought into contact with the hard palate so 
that a predetermined signal voltage from the signal source 12 will be 
applied to the body of the trainee through the electrode S. On the 
opposite surface of the artificial palate device P with which the 
trainee's tongue contacts, in the present case, 64 of the sensing 
electrodes E are distributed as spaced substantially at regular intervals 
as explained with reference to FIG. 1, and each of right and left halves 
respectively of 32 pieces of these sensing electrodes E are connected to 
the respective tongue-contact signal transmitters T.sub.1 and T.sub.2 
through two sets L.sub.1 and L.sub.2 of 32 lead wires. These transmitters 
T.sub.1 and T.sub.2 respectively have the same formation, wherein there is 
used, for example, an oscillator 1 generating pulses of such a 
comparatively high frequency as 20 KHz with a direct current source 
voltage from a very small current source battery preferably contained in 
each of the transmitters. The generated pulses are divided to be of 10 KHz 
in a frequency divider 2 and are sent to a 6-bit counter 3 which is 
provided with six output terminals Q.sub.1 to Q.sub.6 and divides the 
pulses of 10 KHz in the frequency respectively to be 1/2 so that the 
counter 3 provides binary-coded signals of 64 digits to the output 
terminals Q.sub.1 to Q.sub.6. First five of the output terminals Q.sub.1 
to Q.sub.5 are connected to five input terminals of a decoder 4 and this 
decoder receives from the output terminals Q.sub.1 to Q.sub.5 of the 
counter 3 sequentially 32 sets of the binary-coded signals corresponding 
to decimal digits from 0 to 31, repetitively. On the other hand, the 
decoder 4 is provided with 32 output terminals Q.sub.1 to Q.sub.32, so 
that 32 signals of H-level in the binary coded signals from the counter 3 
will be caused to appear sequentially as a scanning signal at the 
respective output terminals Q.sub.1 to Q.sub.32 of the decoder 4. These 32 
output terminals are respectively connected in turn to one of two input 
terminals of each of 32 AND gates of a gate circuit 5, and each of the 
lead wire bundles L.sub.1 and L.sub.2 of 32 lead wires from the artificial 
palate device P is connected to the other input terminal of the respective 
AND gates in accordance with the distributed positions of the sensing 
electrodes E on the artificial palate, so that a proper arranging order of 
these sensing electrodes will be set. Respective output terminals of these 
32 AND gates of the gate circuit 5 are connected sequentially to each of 
32 input terminals of an OR circuit 6, which has one output terminal 
connected to one of two input terminals of an AND gate 11. The output 
terminal of this AND gate 11 is connected through an amplifier 7 to a 
tongue contact signal transmitting means comprising, for example, an 
induction coil 8. On the other hand, the pulses generated in the 
oscillator 1 and binary coded signals provided to the sixth output 
terminal Q.sub.6 of the counter 3 are respectively connected to a pair of 
input terminals of another AND gate 9, and the output terminal of this AND 
gate 9 is connected through an inverter 10 to the other input terminal of 
the AND gate 11 and also to a junction between the AND gate 11 and the 
amplifier 7. 
For the respective components described above of the respective 
transmitters T.sub.1 and T.sub.2, the ones of micro sized type are 
employed and the transmitter as a whole is formed to be a small capsule 
made as flat as possible so as to be easily accommodated between the teeth 
and cheek. 
The receivers R.sub.1 and R.sub.2 placed outside the trainee's body 
respectively comprise, in the present instance, an induction coil which 
receives the electromagnetic wave signals generated and transmitted by the 
induction coils 8 and converts them to corresponding electric signals, the 
thus converted signals are provided to the display device D through the 
cords C.sub.1 and C.sub.2 to be thereby treated so that, for example, 64 
lamps arranged to coincide with the distributed positions of the sensing 
electrodes on the artificial palate P will be put on or off in response to 
the signals from the right and left receivers R.sub.1 and R.sub.2. 
The operation of the transmitters T.sub.1 and T.sub.2 of the above 
described formation shall be explained in the following. In performing the 
articulation study or speech training as described above, the pulses of 20 
KHz generated by the oscillator 1 are divided by the frequency divider 2 
to be 10 KHz, the divided pulses are further divided to be 1/2 by the 
6-bit counter 3, and only the H-level signals from the output terminals 
Q.sub.1 to Q.sub.5 of the counter are provided as the scanning signal of 
32 bits through the decoder 4 respectively sequentially to one of two 
input terminals of the respective 32 AND gates in the gate circuit 5. When 
the trainee to whom the predetermined signal voltage is being applied from 
the signal electrode S of the artificial palate P makes a phonation in 
this state, signals are provided from some of the sensing electrodes E on 
the artificial palate P which are contacted by the tongue at a mode of the 
particular phonation to the other input terminals of the AND gates in the 
circuit 5 which are corresponding to the sensing electrodes thus 
contacted, and these AND gates received the signals from these 
tongue-contacted electrodes are made open in a predetermined order at the 
time when they have received specific ones of the 32 scanning signals 
assigned to these AND gates, whereby the scanning signals to thus opened 
AND gates are passed to the OR circuit 6. Therefore, the OR circuit 6 
sequentially receives at its 32 input terminals 32 H and L level signals 
and provides these signals in series to the single output terminal, and 
the AND gate 11 receives these series signals which are representing the 
linguapalatal contact mode of the particular phonation. 
The AND gate 9 connected at the respective input terminals to the output 
side of the oscillator 1 and to the 6th output terminal Q.sub.6 of the 
counter 3 is made open while the gate is receiving the first-half 32 sets 
of the binary-coded signals in the 64 set signals of 0 to 63 from the 
counter 3, but is closed while receiving the latter-half 32 sets from 32 
to 63 of the binary-coded signals from the counter output terminal 
Q.sub.6, so that the gate 9 will have the 20 KHz pulses from the 
oscillator 1 passed through the gate to the inverter 10 and amplifier 7. 
While the AND gate 9 is closed, that is, during the period of the binary 
coded signals from 0 to 31 from the counter 3, the output side of the 
inverter 10 is made to be at H-level so that the AND gate 11 will be open, 
whereby the series signals of the linguapalatal contact mode provided out 
of the OR circuit 6 will be fed to the amplifier 7 through the AND gate 11 
and to the induction coil 8 to be thereby transmitted out of the 
transmitter T.sub.1 or T.sub.2 as the electromagnetic waves. On the other 
hand, during the period of the binary coded signals from 32 to 63 in which 
the AND gate 9 remains open, the output side of the inverter 10 will be at 
L-level in the same period and the 20 KHz pulses having passed through the 
AND gate 9 are sent directly to the amplifier 7 and transmitted in the 
form of the electromagnetic waves as converted by the induction coil 8. 
That is, the induction coil 8 in each of the right and left transmitters 
T.sub.1 and T.sub.2 sequentially transmits the tongue-contact mode 
informations with respect to the 32 sensing electrodes E on each of the 
right and left halves of the artificial palate P in the form of time 
series and then further transmits continuous signals of 20 KHz over the 
same period as that of the already transmitted informations as above. 
Therefore, these continuous signals of 20 KHz will act as a terminating 
signal of the tongue-contact mode informations on the 32 electrodes and, 
at the same time, as a starting signal of the next series of such 
informations. In this embodiment, as the linguapalatal contact mode 
pattern is displayed on the display device D by the same number of lamps 
in the same arrangement as those of the sensing electrodes, the display 
may be made in such that, for example, all of the lamps are normally kept 
lighted on by the continuous signals of 20 KHz and the lamps corresponding 
to the electrodes not contacted by the tongue are lighted off during the 
series tongue-contact mode informations. 
While, in the above described embodiment, it is shown that the induction 
coil is employed as the tongue-contact signal transmitting means and the 
electromagnetic waves transmitted in response to the signals are received 
by the signal receiving means of the induction coil and converted to 
electric signals, the transmitting and receiving means may be of such 
other type than the induction coil as the one which generates and converts 
some other type of the electromagnetic wave such as a frequency-modulated 
(FM) or amplitude-modulated (AM) electric wave, light or the like. 
Further, in the right and left transmitters T.sub.1 and T.sub.2, at least 
the oscillator 1, the oscillator 1 and frequency divider 2 or the 
oscillator 1 through the counter 3 in the arrangement of FIG. 3 can be 
made only one or one set so as to be common to the right and left 
transmitters. The transmitter may be of course a single transmitter 
connected to all of the sensing electrodes without being divided into a 
pair of right and left transmitters. In order to produce the informations 
representing the tongue-contact modes in the time series signals, further, 
such means which can perform the same function as a shift register may be 
used instead of the same number of AND gates as the sensing electrodes. As 
regards the terminating or starting signal of the series tongue-contact 
informations, any other proper means may be employed in such that, for 
example, only one pulse of such scanning signals as has been described is 
made to be relatively large enough for rendering it distinguishable from 
other information signal pulses. 
In the embodiment shown, further, there has been referred to a measure of 
detecting the linguapalatal contact mode by applying the signal voltage to 
the trainee's body through the single signal electrode S, providing such 
signal voltage through his tongue to the plurality of sensing electrodes 
E, and causing the AND gates in the gate circuit which are corresponding 
to the sensing electrodes contacted by the tongue to be opened. It is also 
possible to employ, however, a reverse measure of providing each of the 
scanning signals to all of the sensing electrodes E from the transmitters 
T.sub.1 and T.sub.2 by a proper means sequentially in accordance with the 
arranged positions of the electrodes, feeding the signals from the 
electrodes with which the tongue has contacted to the single electrode S 
through the tongue and hard palate of the trainee, transmitting as the 
electromagnetic waves the signals provided from the electrode S to a 
transmitter or transmitters disposed within the mouth cavity, and 
receiving the transmitted waves by the receivers R.sub.1 and R.sub.2 
disposed outside the trainee's body. Further, instead of transmitting and 
receiving the tongue-contact signals in the series signal, the signals may 
be of course made to be parallel, but it will be appreciated that the 
particular transmitting and receiving arrangement referred to and shown is 
most preferable in view of the economy in the manufacturing cost. 
As has been described above, according to the present invention, the means 
for transmitting and receiving the tongue-contact signals in a wireless 
type and set within the mouth cavity is used to display the linguapalatal 
contact modes in the dynamic patterns by electrically connecting the 
display device placed outside the body of the trainee with the artificial 
palate fitted within the mouth cavity, whereby the lead wire cords which 
have been conventionally required to be pulled out of the mouth cavity 
through the mouth lips of the trainee are not required, various problems 
caused by such cords are effectively eliminated, natural phonations and 
speeches can be easily performed, and the practical effect in the 
articulation study, speech training and the like with the 
electropalatograph of the kind referred to is remarkable.