Text Telephone Relay Services
While text telephones provide access to the telephone network for the hearing and speech impaired, both parties must have a text device for a conversation to take place. So, what happens when a text user needs to make a doctor's appointment, call the plumber, or even contact a friend or relative who does not have a text telephone? These situations require the use of a TRS (telecommunications relay service).
Many countries provide a nationwide TRS system for text telephone users. In the United States, there is a national TRS operated by states and long-distance carriers that was mandated by the Americans with Disabilities Act. Text telephone users in the United States and Canada can access their TRS service by dialing 711.
Contacting a TRS connects the text user to a CA (communications assistant) who serves as a translator between the text telephone user and the voice user. The CA has a text telephone that connects to one party and then the CA talks and listens in a traditional phone conversation with the other party. Figure 3-6 demonstrates a call between a text user and a voice user using a TRS CA.
Figure 3-6 Text Telephone Call Involving a TRS
Figure 3-6 Text Telephone Call Involving a TRS
Text User
Voice User
Text User
A TRS also provides access for voice users so that they can originate calls to text users. One common example is a teacher's need to contact the deaf parents of a student. A TRS enables this communication to take place without the need for the teacher to own a text device.
In addition to TRS, other relay services are available, too. Most of these are similar to a traditional TRS with minor modifications or enhancements. Table 3-3 provides an overview of other types of relay services for text telephones.
|
TRS Type |
Definition |
|
Text telephone TRS |
This is the traditional TRS associated with text devices. CAs serve as |
|
the bridge between text users and voice users. |
|
|
VCO (voice carry over) |
A variation of text telephone TRS that allows the text user to speak to |
|
the voice user directly while reading the voice user's response. |
|
|
HCO (hearing carry over) |
A variation of text telephone TRS that allows the text user to listen to |
|
the voice user directly while typing responses. |
|
|
STS (speech-to-speech) |
A form of TRS where a CA who is specially trained in understanding |
|
relay |
a variety of speech disorders repeats the caller's words in a more |
|
understandable format. |
CapTel by Ultratec Similar to VCO, CapTel allows a user to speak normally. However, a
CA repeats all incoming responses to this user into an automatic speech recognition system which transcribes them. The other party's voice can then be listened to and his speech is also captioned, appearing as text on the user's specialized phone. Imagine closed captioning (CC) or subtitles for the hearing impaired that are used in the TV world applied to a telephone conversation.
VRS (video relay service) An Internet-based form of TRS for those whose primary language is ASL (American Sign Language). Using videoconferencing equipment, CA translates between ASL and a traditional voice phone call.
IP relay A text-based form of TRS that uses the Internet rather than phone lines to bridge the connection between the disabled user and the CA.
A number of TRS choices are available today for the text telephone user, but a growing number are choosing the newer relay technologies such as IP relay. As broadband Internet access continues to become more accessible, the use of traditional TRS services is declining.
Continue reading here: VCO Voice Carry Over
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