Title: System for text assisted telephony
Abstract: An arrangement for providing captioned telephone service is provided which permits persons who are hard of hearing to receive captioning of their telephone communications as they need it. A personal interpreter/captioned telephone device can dial a relay on a second telephone line while the assisted user if conversing with a hearing user over a first telephone line. The second telephone line connects to a relay which provides voice to text translation service and returns a text stream to the captioned telephone device.
Patent Number: 7,003,082 Issued on 02/21/2006 to Engelke, et al.
| Inventors:
|
Engelke; Robert M. (Madison, WI);
Colwell; Kevin (Middleton, WI)
|
| Assignee:
|
Ultratec, Inc. (Madison, WI)
|
| Appl. No.:
|
634965 |
| Filed:
|
August 5, 2003 |
| Current U.S. Class: |
379/52; 379/93.17; 379/93.15 |
| Current Intern'l Class: |
H04M 11/00 (20060101) |
| Field of Search: |
379/52,931.5,931.7
704/271,277
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Woo; Stella
Attorney, Agent or Firm: Quarles & Brady LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 09/938,194, filed Aug. 23, 2001,
now U.S. Pat. No. 6,603,835, which is a continuation-in-part of application Ser.
No. 09/783,679, filed Feb. 14, 2001, now U.S. Pat. No. 6,594,346, which is a continuation-in-part
of application Ser. No. 09/288,420, filed Apr. 8, 1999, now U.S. Pat. No. 6,233,314,
which is a continuation of application Ser. No. 08/925,558 filed Sep. 8, 1997,
now U.S. Pat. No. 5,909,482.
Claims
We claim:
1. A captioned telephone device for providing captioned telephone service to
an assisted user communicating with a hearing user through a telephone connection
using a relay having speech to text translation capability, the hearing user speaking
words in voice, the device comprising:
a microphone;
a speaker;
a visually readable display;
circuitry to support connection to two telephone lines; and
a microprocessor programmed to operate the device to:
receive a telephone call over a first telephone line directly between the assisted
user and the hearing user;
initiate a telephone connection over a second telephone line to the relay;
transmit the voice of the hearing user over the second telephone line to the
relay so that the relay can converting the words spoken by the hearing user into
text and transmit the text created by the relay back to the device over the second
telephone line; and
display the text on the display within sight of the assisted user such that captioning
of the communication session is provided to the assisted user.
Description
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The present invention relates to the general field of telephone communications.
In more particular, the invention relates to systems to assist telephone communications
by those persons who are deaf, hard of hearing, or otherwise have impaired hearing capability.
Most modern human communications in both social and business environments takes
place through sound communications. Yet within modern society there are many persons
who have attenuated hearing capability. To assist those persons in making use of
our telephonic communication system built for the hearing majority, there has been
developed a system of telephone communication which has been principally used by
the deaf community. That system makes use of a category of device known variously
as a telecommunication device for the deaf (TDD), text telephone (TT) or teletype
(TTY). Current TDDs are electronic devices consisting of a key board and a display
as well as a specific type of modem, to acoustically or directly couple to the
telephone line. Modern TDDs permit the user to type characters into their keyboard,
with the character strings then encoded and transmitted over the telephone line
to be displayed on the display of a communicating or remote TDD device.
Most TDD communication is conducted in an idiosyncratic code specific to the
community of TDD users. This code, known as Baudot, evolved historically at a time
when many telecommunication devices for the deaf were based on mechanical or electromechanical
devices rather than the current technology based on digital electronic components.
Accordingly, the Baudot protocol was constructed for a set of constraints which
are no longer relevant to present date devices. The original Baudot protocol was
a unidirectional or simplex system of communication conducted at 45.5 Baud. The
conventional Baudot character set was a character set consisting of 5 bit characters
and the system encodes the bits of those characters in a two-tonal system based
on carrier tones of 1400 and 1800 Hertz.
The system of TDD communications is widely used and in fact has become indispensable
to the deaf community throughout the industrialized world. Deaf persons extensively
communicate with their neighbors and with other deaf and hearing people remotely,
using the TDD system. In addition, systems have been developed to facilitate the
exchange of communication between the deaf community and hearing users who do not
have access to or utilize a TDD device. In the United States, telephone companies
have set up a service referred to as a "relay." A relay, as the term is used herein,
refers to a system of voice to TDD communication in which an operator, referred
to as a "call assistant," serves as a human intermediary between a hearing user
and a deaf person. Normally the call assistant wears a headset that communicates
by voice with the hearing user and also has access to a TDD device which can communicate
to the deaf user using a TDD appropriate protocol. In normal relay operations in
the prior art, the call assistant types at a TDD keyboard the words which are voiced
to her by the hearing user and then voices to the hearing user the words that the
call assistant sees upon the display of his or her TDD. The call assistant serves,
in essence, as an interpreting intermediary between the deaf person and the hearing
person to translate from voice to digital electronic forms of communication.
A system to assist users of the telephone system who are hard of hearing but
not
deaf has been described. This system, sometimes referred to as text enhanced telephony,
makes use of the existence of relays to supplement telephone communications for
users who can hear, but have attenuated hearing capabilities. This systems includes,
in its simplest embodiment, a visually readable display connected in series between
the telephone used by the assisted user and the connection to the telephone network.
The text enhanced telephone call is connected through a relay which transmits both
the voice of the hearing user at the other end and a text stream of the words spoken
by that user on the same telephone line. The details of the concept and of some
embodiments of that system are disclosed in U.S. Pat. No. 6,075,842, the disclosure
of which is hereby incorporated by reference.
BRIEF SUMMARY OF THE INVENTION
The present invention is summarized in that a relay system to facilitate the
translation of information and communication between deaf and hearing persons includes
a call assistant who re-voices the words of the hearing person which are spoken
to the call assistant. The words spoken by the call assistant are recognized by
a speech recognition computer program which has been trained to the voice pattern
of the call assistant, such that the words are promptly translated into a high
speed digital communication protocol. That high speed digital communication message
is then transmitted electronically promptly by telephone to a visual display accessible
to the deaf person.
It is an advantage of the invention described herein that the call assistant
does
not have to type most, if any, of the words spoken by the hearing person in the
communication session so that the overall speed of communications from the hearing
person to the deaf person is dramatically increased.
It is an object of the present invention that the design and utilization of a
relay operated in accordance with the protocols described herein permits the introduction
of small hand-held personal interpreter which will enable on the spot communications
between deaf persons and hearing persons wherever the deaf persons might go.
Other objects, advantages and features of the present invention will become
apparent from the following specification when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic block diagram of a re-voicing relay.
FIG. 2 is an exterior view of a personal interpreter enabled by the relay of
FIG. 1.
FIG. 3 is a schematic block diagram of the personal interpreter of FIG. 2.
FIG. 4 illustrates the operation of a captioned telephone service supported
by a relay.
FIG. 5 is a schematic illustration of the concept of the two wire captioned
telephone device connection with sound inter-connection.
FIG. 6 is a schematic illustration of the connection of a personal interpreter/captioned
telephone device connected to two telephone lines.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is intended to provide an alternative arrangement for the
delivery of text assisted telephone services, also called captioned telephone,
to a telephone system user with diminished hearing. The present system is intended
to take advantage of two developments in the field of assisted telephone services,
the personal interpreter and the re-voicing relay. The arrangement for using these
capabilities here is designed not to provide text services for the profoundly deaf,
but to provide a text assistance service for those who can hear, but who may have
diminished hearing. This service is designed to supplement rather than replace
the transmission of the spoken voice word to the assisted user. To assist understanding
what is contemplated here, the basic technologies of the personal interpreter and
the re-voicing relay will be described here first, after which the description
will return to the main topic, text assisted telephone services or, as they are
also known, captioned telephone services.
The personal interpreter is intended to be a small portable device capable of
delivering, with the support of a relay, text to a deaf user of any human conversation
occurring in the presence of the personal interpreter. The personal interpreter
is set up to connect telephonically to a relay, transmit spoken words to the relay,
and then display for the assisted user the text of the words transmitted over the
telephone connection to the relay. To make the personal interpreter work more seamlessly
to produce more conversation-like communication, a faster relay methodology was
needed. To fill this need, the re-voicing relay was designed.
The re-voicing relay is based upon the underlying technology of using voice recognition
software, operated by a call assistant (a "CA"), to assist in the voice to text
translation inherent in providing relay services. The re-voicing strategy is described
in U.S. Pat. No. 5,909,482, the disclosure of which is hereby incorporated by reference.
The re-voicing relay has its first implementation in providing voice to text transcription
services for the deaf. However, the relay voice to text transcription service has
use for users other than those who are deaf. It is envisioned that there are a
number of hearing or partially hearing users who would have reason to benefit from
voice to text transcription services. Relay voice to text service might also be
useful for any application in which it is desired to supplement voice communications
by a text transcription of the voice spoken on the telephone. Thus, while the operation
of the relay will sometimes be described here by referring to an "assisted user,"
who may be deaf or hard of hearing, but who also may be a normally hearing person
who simply wants text assistance for some reason. The user at the other end of
the line will be referred to here as the hearing user, simply for the purpose of
having something to call that person, even though both users may be hearing.
Personal Interpreter
Shown in FIG. 2 is an illustration of what a personal interpreter
10
can look like. This would be a small hand held device typically the size of a small
hardbound book. It would have a keyboard of minimal size, but useable by a deaf
person who can type. It would have a two or four line display, but the display
could be any size that conveniently fits in the case of the device. The device
would also have a key or switch which would initiate its operation.
Shown in FIG. 2 is a schematic block diagram of the internal mechanics of the
personal interpreter. The personal interpreter keyboard shown at
12 and
its display as shown at
14. Inside the interpreter itself is a microprocessor
shown at
16. Not shown, but included within the personal interpreter, would
be the appropriate memory and interface devices so as to allow the microprocessor
to be programmed and to operate the personal interpreter and perform its functions,
in a manner well known in the art. Also inside of the personal interpreter is a
modem
18. The modem
18 is preferably a modem specifically designed
for interface with the deaf telecommunications system. Most telecommunications
with the deaf community are conducted using a Baudot type code. One useful alternative
is for the modem be designed to use the enhanced form of Baudot communication known
as "Turbo Code" (Ultratec), which is generally described in U.S. Pat. No. 5,432,837,
U.S. Pat. Nos. 5,517,548, and 5,327,479, the disclosure of which is hereby incorporated
by reference. Another alternative is that the modem use a new variant of Turbo
Code, one which uses higher carrier frequencies (in the range of 3000-3500 hertz)
and a faster baud rate (over 100 baud). The most preferred alternative is for the
modem to use a digital communication protocol which can both transmit and receive
digital packets which contain either or both of voice and text. The output of the
modem is preferably wired to a cellular telephone
20 included within the
case of the personal interpreter
10. The cellular telephone
20 has
a suitable antenna provided on it so that it may dial a cellular telephone network
by radio frequency communications of the type normally conducted by cellular telephones.
The personal interpreter also includes jack
28 to connect to a conventional
wired or land-line telephone line as well. The personal interpreter also includes
a microphone
22 and a speaker
24. A filter
26 connects the
speaker
24 and the microphone
22 to the telephone
20.
A brief description of the operation and functionality of the personal interpreter
reveals the dramatic improvement and convenience and portability that this device
gives to text assisted people. A assisted user could go into an establishment,
be it a government office or retail facility, in which there are only hearing persons.
The assisted person would carry with him or her the personal interpreter
10.
The assisted user would then place the personal interpreter
10 upon a counter
or other surface, open it up, and press the initiation key or start button. The
microprocessor
16 and modem
18 of the personal interpreter then power
up and act in many ways like a normal TDD device operating in telecommunication
standard, such as Turbo code. However, there is one critical difference. The start
or initiation key further causes the microprocessor
16 of the personal interpreter
to dial a relay to set up a relay communication session and includes in its communication
with the relay a message, using the enhanced command features available in advanced
telecommunication protocols, such as Turbo Code, to initiate a special format of
relay call adapted for the personal interpreter. Other codes which permit command
functions, such as ASCII or CC ITT, could also be used. The first operation is
to activate the cellular telephone and direct the cellular telephone to dial the
number of a relay operating in accordance with the method of the present invention.
The cellular telephone dials the relay. Obviously, no wired connection is required
to allow the cellular telephone function to establish a telephone connection with
the remote relay, but alternatively the jack
28 to a conventional telephone
line could be used. In addition, when the relay answers the telephone connection,
the microprocessor
168 of the personal interpreter
10 is instructed
to provide command codes to the remote relay. These command codes, a feature possible
through the use of Turbo Code, permits the personal interpreter to tell the relay
that this is a personal interpreter-type relay communication session. All of this
can happen in the time necessary to initiate the cellular call, perhaps two to
ten seconds.
Then, the assisted person can use the personal interpreter to translate words
spoken by hearing persons in the presence of the personal interpreter into visually
readable text. This is done by the personal interpreter
10 through an unseen
relay. Words spoken by the hearing persons in the presence of the personal interpreter
10 are picked up by the microphone
22. Those words are then transmitted
through the cellular telephone
20 to the remote relay. The relay, operating
as will be described below, then immediately transmits back, in enhanced Turbo
Code, a digital communication stream translating the words that were just spoken.
The words are received by the modem
18, and the microprocessor
16
in the personal interpreter
10, and it is displayed promptly upon the display
screen
14. If the assisted person can speak, he or she may then answer the
hearing person with a spoken voice, or, the assisted person may alternatively type
upon the keyboard
12. If the assisted user types on the keyboard
12,
the personal interpreter transmits the communication by digital communication to
the relay. The call assistant at the relay then reads and speaks the words typed
by the assisted user which are transmitted to the speaker
22 contained in
the personal interpreter into a voice communication which can be understood by
the hearing users. The filter
26 filters out the digital communication frequencies
from the sound generated by the speaker
22. Thus, in essence, the assisted
person has a personal interpreter available to him or her at all times of the day
or night wherever the assisted person is within the range of the cellular telephone
system. Also, because the relay is preferably operating in accordance with the
fast translation methodology described below, a very conversation-like feel can
occur in the communication session between the assisted user and the hearing persons
in the presence of the personal interpreter
10. In order for this communication
session to be satisfactory to the hearing users as well as the assisted person,
however, the relay must operate exceedingly rapidly. It is, in part, to meet the
need for the exceeding rapidity of this conversational style of communication that
the re-voicing relay protocol has been designed.
Re-voicing Relay
Shown in FIG. 1 is a relay intended to provide the voice to text capability
to support the personal interpreter, and which can also support other voice to
text services to provide services for assisted users. FIG. 1 is intended to show,
in schematic fashion, how such a relay system can be set up. Shown at
32
is a telephone of a hearing person. Instead of a telephone of a hearing person,
the input could also be the microphone of the personal interpreter translator
10
shown in FIGS. 2 and 3. The telephone of the hearing person
32 is connected
through a telephone line
34 to a voice input buffer
36 at the relay.
The telephone line
34 can be an actual physical land line, or two pair between
the telephones, or can be a cellular or other over-the-air telephone linkage. The
voice input buffer
36 is a simple buffer to ensure temporary capture of
the voice in the event that the call assistant gets behind and needs to buffer
or delay the voice of the hearing person. In any event, the output of the input
voice buffer
36 is provided to a headset
40 where earphones
38
produce the sound of the remote speaking person in the ear of the call assistant.
The call assistant is wearing the headset
40 and sitting at a computer
42
capable of communicating in an enhanced Baudot communication, such as Turbo Code
or whatever other code protocol is being used. However, typically the call assistant
does not type the words which the call assistant hears in his or her earphone
38.
Instead, the call assistant then speaks the words which he or she hears in the
earphones
38 into a microphone
39 in the headset
40. The microphone
39 on the headset
40 is connected to transmit the voice of the call
assistant to the computer
42 at which the call assistant sits.
The computer
42 has been provided with a voice recognition software package
which can recognize the spoken voice of the call assistant and immediately translate
words spoken in that voice into a digital text communication stream. It is a limitation
of currently available speech recognition software that the software must be trained
or adapted to a particular user, before it can accurately transcribe what words
the user speaks. Accordingly, it is envisioned here that the call assistant operates
at a computer terminal which contains a copy of a voice recognition software package
which is specifically trained to the voice of that particular call assistant. It
is also important that the voice recognition system be capable of transcribing
the words of the voice of the call assistant at the speed of a normal human communication.
It has been found that a recently available commercial voice recognition package
from Dragon Systems, known as "Naturally Speaking," is a voice recognition software
which will accomplish this objective and which will translate to digital text spoken
words of a user at the normal speeds of human communication in conversation when
operating on conventional modern personal computers. A voice recognition software
system known as "Via Voice" from IBM provides similar functionality.
The computer terminal
42 of the call assistant then translates the text
created by the voice recognition software to a modem
46 out through a telephone
line
48 back to the display
50 located adjacent to the assisted person.
The display
50 can be a conventional TDD located at the home of the remote
assisted user, or can be the display
14 of the personal interpreter
10,
or can be any other display or text capture device used by an assisted user.
For reasons that will become apparent, there is also a connection from the microphone
39 of the headset
40 of the call assistant to the incoming telephone
line
34 through a switch
52. The switch
52 can physically
be an electrical switch located between the microphone
39 and the telephone
lines
34 and the computer
42 or, as an alternative, it can be a software
switch operating in the computer
42 which passes the voice of the call assistant
through to the telephone lines as voice, or not, under conditions which are selected
by the call assistant, by choices he or she makes at the keyboard
44 of
the computer
42. The switch
52 is functionally a single pole double
throw switch although, of course, if this function is performed by the computer
it will be a logical not a physical switch. In the simplest embodiment, the switch
52 is a simple single pole dual throw foot switch readily accessible to
the call assistant which passes the voice of the call assistant from the microphone
either out onto the telephone line
34 or to the computer
42.
It is a further enhancement to the operation of the relay constructed in accordance
with the present invention that the earphones
38 have noise attenuating
capability. Noise canceling earphones are commercially available today or, for
this purpose, the computer
42 can be provided with noise canceling sound
generation software which would create sound transmitted to the earphone
38
so as to cancel the sounds of the call assistant's own voice. The noise attenuation
or cancellation avoids distracting the call assistant, since he or she would then
be less distracted by the words that he or she has spoken, and thus would be less
likely to be distracted from the concentration of the task of re-voicing the sounds
of the voice heard in the call assistant's ear.
Similarly, another option which would be advantageous is that the software
providing for the creation of the digital text string by voice recognition be buffered
in its output flow to the modem
46. Before the computer
42 would
pass the data on to the modem
46, the data would first be displayed on the
computer screen of the computer
42 for review by the call assistant. The
purpose of this option would be to permit the call assistant to use the keyboard
to type or correct hard-to-spell words, or to create corrections of any misinterpretations
created by the voice recognition software, from the words spoken by the call assistant.
It is anticipated that if such an option is utilized, it would require fairly infrequent
use of the keyboard by the call assistant, since frequent use would clearly slow
down the through-put of the communications.
The relay of FIG. 1 can operate with normal TDDs or with a personal interpreter
as shown in FIGS. 2 and 3. In either event, the hearing person speaks in the telephone
32 and the words are transmitted through the telephone line
34 to
the voice buffer
36. The voice buffer
36, again operating under the
control of the call assistant, would buffer the voice signals from the hearing
user as needed for the call assistant to keep up. The call assistant would hear
the voice of the hearing user through the earpiece
38 and then would re-voice
those same words into the microphone
39. The words that the user speaks
into the microphone
39 would be fed to the computer
42 where the
voice recognition software, trained to the voice of the call assistant, would translate
those words into a digital text stream. The digital text stream would be turned
into a digital communication stream by the modem
46 and passed on the telephone
line
48 to a display
50 which can be observed by the assisted user.
Experience has shown that using currently available technology the delay between
the time the hearing user speaks into the telephone
32 and the time the
words appear on the display
50 of the assisted user is a modest number of seconds.
In the reverse, when a non-speaking assisted user types onto his or her telecommunication
device, the digital signals are transmitted to the computer
42 which displays
them for the call assistant who then voices those words into the microphone
39
which words are then transmitted onto the telephone line
34. Note that the
presence of the switch
52 is therefore important in this mode. Since the
voice of the call assistant serves two different functions in the operation of
this system, the signal on the call assistant's voice must be switched so that
the hearing user
32 only hears the voice for the communications which are
intended to be directed to that person. The switch
52 allows for the voice
of the call assistant only to be directed to the hearing person at the appropriate times.
Note that if the relay of FIG. 1 is used to facilitate a translation based on
a personal interpreter such as that shown in FIGS. 2 and 3, there will be only
one telephone line between the personal interpreter and the call assistant. In
essence, in a modification of FIG. 1, the telephone
32 and the display
50
would both be within the personal interpreter
10. There would be only one
telephone line, a cellular link, between the personal interpreter
10 and
the call assistant. Note therefore that the voice of the call assistant and the
digital communications created by the computer
42 would then travel on that
same telephone linkage to and from the personal interpreter
10. It is therefore
important for this embodiment that the personal interpreter
10 have appropriate
filtering (i.e. the filter
26) to filter out the digital communication carrier
frequencies of the digital communications protocol, so that they are not heard
by hearing listeners in the presence of the personal interpreter
10. The
telephone line must still carry voice signals, however, so that the spoken words
articulated by the call assistant in response to digital instructions from the
deaf user can be properly broadcast by the speaker contained within the personal interpreter.
The provision for filtering of the digital frequencies can be done in any number
of ways with two being the principal preferred methodologies. If Turbo Baudot communications
are conducted at the conventional Baudot frequencies of 1400 and 1800 Hertz, the
personal interpreter
10 could be provided with notch filters
26 to
filter out signals at those particular frequencies. It has been found that such
notch filters still permit the transmission of audible and understandable human
speech, even if they filter at those particular frequencies. As an alternative,
it is possible to change the Baudot frequencies to those which are much higher,
such as frequencies of 3000 to 3500 Hertz. If this alternative is selected, the
personal interpreter
10 is then provided with a low pass filter which permits
low frequency sounds to go to the speaker to be broadcast into the environment
of the personal interpreter, while high frequencies are excluded.
It is also specifically envisioned that the filter of text communications signals
from the voice signal can be done digitally or logically rather than by analog
filter. For example, it is possible to implement the modem at site of the assisted
user using a digital signal processor, or DSP, integrated circuit. Such a DSP chip
can be programmed to recognize to separate voice signals from text communications
signals and to pass along only the voice signals to the speaker at the location
of the assisted user. It is also contemplated that the telephone linkage between
the relay and the assisted user could be a digital connection rather than an analog
telephone line. For example, the linkage between the relay and the assisted user
could be a digital wireless linkage or an internet protocol linkage, wired or wireless.
In either of these instances, the appropriate protocol calls for the transmission
of packets of digital data, the packets being marked to indicate the type of information
carried in the packets. The packets might contain, for example, voice signals which
have been digitized or might contain simple digital information representing the
text string of a conversation. In the instance of such a digital packet type communication
protocol, the filtering out of the digital text information could be implemented
simply by only converting the packets marked as voice back into sound. Packets
marked as containing digital information would be used to recover the text information
for display to the assisted user.
Captioned Telephone
As mentioned earlier, captioned telephone is a technology intended to provide
text assistance to assisted user during the course of a voice telephone communication
session. As will become apparent from the discussion below, a captioned telephone
connection can be a single line connection or a multiple line connection. There
are advantages and disadvantages of each approach. A single line connection is
known in the art, as exemplified by U.S. Pat. No. 6,075,842, mentioned previously.
The advantages and details of the use of a multiple line connection are described
below. The discussion of captioned telephone will begin with a single line connection.
Shown in FIG. 4 is an illustration of how a typical telephone call involving
a single line captioned telephone would be set up. The hearing user at telephone
62 communicates through a telephone line
64 with the relay, indicated
at
66. The relay, a re-voicing relay, communicates through a telephone line
68 with the assisted user. At the site of the assisted user is a telephone
70 used by the assisted user and also a captioned telephone device
72.
The telephone
70 is conventional. The captioned telephone device
72
is constructed to accomplish two objectives. One objective is to filter, or separate,
the digital signals carrying the text information from the voice signal. The other
objective is to take the digital signals and create a visual display of the text
information for the assisted user. This device is thus intended to assist the user
to understand a greater portion of the conversation by providing a visually readable
transcription of the text of the telephone conversation so that the assisted user
can read any words that he or she cannot hear properly. While the captioned telephone
device
72 of FIG. 4 is illustrated as a separate stand-alone device from
the telephone
70, those of skill in the art can readily appreciate that
the two functions can be combined in a special capability telephone station. Such
a special purpose station can both provide conventional telephone service and also
include a display which can be used to provide captioning for an assisted user.
The two line captioned telephone is indicated in FIG. 5. In its simplest embodiment,
the two-line captioned telephone can be conceptually thought of as a personal interpreter
used to provide text assistance to a telephone user. Thus in FIG. 5, the telephone
of the hearing user
62 and the telephone of the assisted user
70
are connected directly by a simple single telephone connection, indicated by the
telephone line
64. The assisted user then uses a personal interpreter/captioned
telephone ("PICT") device
74 to connect to a relay
76 over a second
telephone line or connection, indicated at
78. There must be some form of
communication between the telephone of the assisted user
70 and the PICT
device
74, so that the voice of the hearing user can be transferred to the
second telephone line
78 to the relay
76. At its simplest, the connection
can be a simple acoustic connection, such as placing the sound pick-up microphone
of the PICT device in such a location that the sound of the hearing person's voice
is picked up and transmitted to the relay. A microphone connected to the PICT device
74 could be placed on the handset of the assisted user's telephone
70.
However, it is preferred that the PICT device be electronically connected to the
telephone of the assisted user so that the voice of the hearing user can be transmitted
to the relay call assistant with minimal interference or noise. The PICT device
includes a visually readable display and suitable decoding electronics and software
so that the device can receive and display a text stream received from the relay
over the second telephone line.
The main advantage of the two-line approach to captioned telephone is that the
captioned telephone service can be added to a telephone call already in progress.
By contrast, to use single line captioned telephone for an incoming call, the call
must directed through the relay to the assisted user at the beginning of the call.
For a two-line captioned telephone call, however, the call can be started as a
normal telephone communication session, without the relay or the captioning. Then,
if the assisted user decides captioning would be helpful to his or her understanding
of the conversation, the captioning service can be added while the call is in progress.
To add the captioning service, the assisted user simply has the PICT device dial
the relay over the second telephone line. The voice of the hearing user is then
transmitted over the second telephone line to the relay. The relay converts the
voice to text and the text stream created by the relay returns to the assisted
user, also over the second telephone line. Note that in this arrangement, as indicated
in FIG. 5, voice and text are transmitted in opposite directions over a single
telephone line between the PICT device and the relay, voice going to the relay
and text returning on the same line. This arrangement of voice and text is the
same as used for the personal interpreter.
One device intended to implement the two-line captioned telephone approach is
illustrated in FIG. 6. The PICT device
80 of FIG. 6 is an analog device
connected in series between the telephone line
64 to the hearing user and
the telephone
70 of the assisted user. As seen in FIG. 6, the telephone
line
64 is connected directly through the PICT device
80 to the telephone
70. However, that telephone connection is also connected through a transformer
82 to a 2-wire to 4-wire converter
84. Connected to the output of
the converter
84 is a low pass filter
86, the output of which is
the input to an amplifier
88. The output of the amplifier
88 is connected
to a 2-wire to 4-wire converter
89 which connects, in turn, to the telephone
line
78 which connects to the relay (not shown here). The input signals
from the telephone line
78 are connected to a hi-pass filter
90,
the output of which passes through a receive modem
92 to a microcontroller
94. The microcontroller operates the display
96. The microcontroller
also includes the capability to generate DTMF dialing tones and impress those tones
on the telephone line
78 when it is time to dial the relay. Thus here the
single PICT device
80 connects to two telephone lines. A call can be initiated
or received by the assisted user in the same manner as with a conventional telephone,
using only the first telephone line
64. When the user wishes to invoke the
captioning service, the assisted user presses a button,
97, on the PICT device
80 that causes the device to automatically dial the relay on the second
telephone line
78. The PICT device automatically transmits the voice signals
on the first telephone line to the second telephone line (through the low-pass
filter
86) for transmission to the relay. At the relay, the voice is converted
into text and a text stream is sent back down the telephone connection
78
to the PICT device. The PICT device filters the text data, at the hi-pass filter
90, and transmits it to the microcontroller
94 for display to the
user. None of the text data, and no digital carrier signals, are heard by either
the hearing user or the assisted user. Normally the hearing user does not even
need to be aware that captioning is being used on the call.
This example assumes that the digital carrier signals for the text message are
carried on high frequencies, and the low pass and high pass filters are used to
separate voice from text. While this filtering can be implemented as an analog
filter, in many telephonic systems today, digital forms of communication are used.
Using a digital communication protocol between the relay and the PICT device, communication
is in the form of digital data packets of either text or digitized voice. In that
event, the logical filtering simply consists of not creating any acoustic noise
from the packets designated as carrying text.
Several physical versions of the PICT device are contemplated. In the version
illustrated in FIG. 5, the PICT device is a stand-alone appliance inserted in series
between the telephone of the assisted user and the telephone jack on the wall of
the user's home. It may also be convenient for the user to package the PICT device
as a single two-line unit intended to provide both conventional telephone service,
as well as captioned telephone services. The device could look like a normal telephone,
but have a display. The captioned telephone feature would be activated by a button
or key, which would cause the unit to dial a pre-selected relay and set up a captioning
session, whether or not a call on the other line is yet in progress. The voice
signals incoming on the first telephone line from the hearing user would be transferred
electronically to the telephone line to the relay. Text signals would be transmitted
on that same telephone line back from the relay to the PICT device, which would
display that text for the assisted user. Since the re-voicing relay operates with
only a very slight time delay, the text display for the assisted user would trail
the hearing person's voice slightly, but the text would still assist the user in
comprehending the conversation.
It is a desirable feature of the two-line captioned telephone arrangement that
the use of the captioning service is transparent to the hearing user. The hearing
user would dial to connect to the assisted user as with any other telephone user.
The assisted user invokes the captioned telephone service without the need to involve
the hearing user at all. The service can be used equally well and transparently
for both incoming and outgoing calls.
It is also envisioned that the captioned telephone service can be implemented
in a way that uses three telephone lines. One line is for voice communications
with the hearing user. The second line is directly connected to the first line
so that the voice of the hearing user is transmitted to the relay. The third line
is a connection to transmit the text stream from the relay to the station of the
assisted user.
In the implementation of a relay providing captioned telephone service, the relay
receives the voice of the hearing user and transmits both a digital text message
stream and the voice of the hearing user over a telephone connection to the station
of the assisted user. It is to be understood, however, that a conventional telephone
single line connection is only one example of a telephonic connection that can
be used in this arrangement. Digital wireless connection, or PCS connection, or
even internet protocol (IP), wired or wireless connection can be used to connect
the relay to the assisted user, so long as the connection in capable of trasmitting
voice to that user.
Thus the term telephone line as used in this specification is intended not only
to apply to a traditional land-line two-wire telephone line, but also to all equivalents
that offer similar functionality. Each of the telephone lines could be, for example,
a portion of the bandwidth of an ISDN or DSL service. The telephone line could
be an analog or digital cellular telephone link or a PCS connection. The PICT device
could also be connected to the internet communication in IP, and in that event
the two telephone lines would simply be simultaneous digital data exchange with
two remote locations.
It is to be understood that the present invention is not limited to the particular
illustrations and embodiments disclosed above, but embraces all such modified forms
thereof as come within the scope of the following claims.
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