Telecommunications relay service

Once the most common type of TRS call, TTY calls involve a call from a deaf or hard-of-hearing person who utilizes a TTY to a hearing person. In this type of call, typed messages are relayed as voice messages by a TRS operator,[1] (also known as Communication Assistant (CA),[2] Relay Operator (RO),[3] Relay Assistant (RA),[4] or relay agent (agent)), and vice versa. This allows callers who are unable to use a regular telephone to be able to place calls to people who use a regular telephone and vice versa. When the person who is hearing is ready for a response, it is customary to say "go ahead" or "GA" to indicate that it is the TTY (teletypewriter) user's turn to talk and "stop keying", "SK", or "ready to hang up" when ending the call and vice versa. This mode of communication has largely been superseded by other modes of communications, including the utilization of IP relay, VPs, VRS, and VRI.

A common type of call is voice carry over, VCO. This allows a person who is hard of hearing or deaf but can speak to use their voice while receiving responses from a person who is hearing via the operator's typed text. There are many variations of VCO, including two-line VCO and VCO with privacy.

The operator will not hear the VCO user's voiced messages and the VCO user does not need to voice GA. The operator will hear the person who is hearing, and the person who is hearing must give the GA each time to alert the operator it is the VCO user's turn. The VCO user does not need to voice GA, because the VCO user types it or presses the "VCO GA" button on the VCO phone when it's the voice user's turn to talk.

Two-line VCO allows a VCO user using a TTY or computer to call a TRS operator, who in turn calls the VCO user on a second telephone line, which serves as the voice line. The user puts the operator on a brief hold to initiate a three-way call with the hearing person. This method is frequently used by people who are hard of hearing and like to use some of their residual hearing as well not having to say "go ahead". With two-line VCO, the VCO user and the voice user can interrupt each other. VCO with Privacy cannot be used with two-line VCO, because the operator, VCO user, and hearing person are on a three-way call.

A less common call type is hearing carry over (HCO). HCO allows a person who is speech-disabled but can hear to use their hearing while sending responses to a person who is hearing via the HCO user's typed text. The operator voices the HCO user's typed messages, and then the HCO users picks up the handset and listens to the other voice user's response. There are many variations of HCO, including two-line HCO and HCO with privacy.

The operator will not hear the voice user's voiced messages and the voice user does not need to voice GA. The operator will voice for the person who is Speech-Disabled, and the person who is Speech–Disabled must give the GA each time to alert the operator it is the voice user's turn. The voice user does not need to voice GA, because the HCO user can hear when the voice user finishes talking.

Similar to 2-line VCO, 2-line HCO allows an HCO user using a TTY or computer to call a TRS operator, who in turn calls the HCO user on a second telephone line, which serves as the voice line. The user puts the operator on a brief hold to initiate a three-way call with the hearing person. This method is frequently used by people who are Speech-Disabled and like to use some of their residual speech as well not having to type "GA". With 2–Line HCO, the HCO user and the voice user can interrupt each other. HCO with Privacy cannot be used with 2–Line HCO, because the operator, HCO user, and hearing person are on a three–way call.

Speech to speech (STS) exists for people who have speech disabilities. A specially–trained STS TRS operator revoices what the person with a speech disability says. STS is often used in combination with VCO for people who are deaf and have somewhat understandable speech, as well as two–Line HCO users. STS enables people with speech disabilities to call others (able-bodied speakers and other people with speech disabilities). It also enables people without speech disabilities to call people with speech disabilities. Anyone can call 711 in the U.S. and ask for Speech to Speech. STS is also available in Australia, New Zealand and Sweden.

Many STS users have Parkinson's disease, cerebral palsy, ALS, multiple sclerosis, muscular dystrophy or stroke. Other users stutter or have had a laryngectomy. STS also helps speech synthesizer users, users of Augmentative and Alternative Communication (AAC.) AAC users can set their device next to a speakerphone. They ask the STS CA set up the call, negotiate the menu, introduce the call explaining AAC and then go into the background. This enables AAC users to communicate independently once the other party is on the line.

Telebraille also exists for people who are deafblind with the use of a TTY with a braille or regular keyboard and a refreshable braille display or LVD (Large Visual Display). A relay call of a user who is deafblind is directly related to a relay call of a TTY user, however, the text transmission speed is often reduced to increase the ability of the user who is deafblind to comprehend the moving braille on the braille TTY or large print on the LVD. Telebraille relay operators must be familiar with Braille contractions that users who are deafblind may use. Due to its implementation of a smaller keyboard, some TTY users with mobile disabilities may prefer to use a Telebraille, regardless of a sight disability or lack thereof.

Captioned telephone is a hybrid communication method that enables people who are hard of hearing, oral deaf or late–deafened to speak directly to another party on a telephone call.[5] Typically, a telephone that displays real-time captions of what the hearing party speaks during a conversation. The captions are displayed on a screen embedded in the telephone base. A captioned telephone can also function exactly like a VCO when the user switches the device to VCO mode to do things like communicate with an HCO user directly, without relay. Captioned telephone services can be provided in traditional telephone environments as well as in VOIP environments.

Captions are created by a communications assistant using a computer with voice recognition software. The communications assistant listens to and revoices the hearing party's side of the conversation into the microphone of a headset. A voice recognition program creates the captions and they are sent out to the captioned telephone where they are read by the user.

Prior to 2005, captioned telephone service was only available to people in states that had captioned telephone service as part of their state relay program. In 2005, the FCC made IP CTS a part of the federally mandated services.

IP CTS Requires an internet connection to deliver the captions to the user. Most also rely on their regular land-line telephone for the audio portion of the call, but some configurations of IP CTS allow the use of VOIP to carry the call audio. IP CTS has allowed captioned telephone service to be provided on smartphones and tablets.

Captioned telephone can also be used with two lines. This is especially useful for users who prefer to give out their home phone number alone, instead of both the captioning service number and the toll-free captioning service number or for users who prefer to turn captions on and off anytime during the call. 2–Line captioned telephone can also be used with other relay services. For example, STS can be used with a 2–Line captioned telephone, for captioned telephone users with speech disabilities. 2–Line captioned telephone is only available to people in states that have 2–Line captioned telephone as part of their relay service or federal employees/contractors and American Indians.[6][7]

Web-based captioned telephone enables telephone calls to be placed with captions, by utilizing the World Wide Web browser window of a computer or smart phone. It is similar to a traditional captioned phone call except the user's own telephone equipment is used, whilst the captions are viewed online instead of in the captioned telephone display screen.[8]

Many other call type variations are possible, including VCO to VCO, HCO to HCO, HCO to TTY, and VCO to TTY. Fundamentally, relay services have the ability to connect any two callers with different abilities over the telephone network. Voice callers in the United States can now access the service with a universal number: 711.[9] After the number is dialled, the caller will receive instructions to complete the call to reach deaf callers.

IP relay services, called Web-based text relay services in Europe, provide functionality similar to TDD/TTY relay services. Instead of using telephone lines and TDD/TTY devices, they use an Internet connection and software running on computers or smartphones.

When using an IP relay service for an emergency call like 911 or 112, the relay operator will ask for the street address, city, and state from which the call is originating. If this information is not provided, the relay operator will be unable to complete the emergency call.

Most IP relay services support Web browsers, mobile phone apps, text messaging, WAP, instant messaging, and Text over IP (ToIP). Support for these technologies has enabled many Internet-connected devices to be used with relay services, including desktop and laptop personal computers, mobile phones, and PDAs.

Video relay service (VRS) allows people who use sign language to place phone calls by signing instead of typing. The VI (video interpreter) uses a webcam or videophone to voice the deaf, hard-of-hearing or, speech-disabled person's signs to a hearing person and sign the hearing person's words to the deaf, hard-of-hearing or speech-impaired person.

Video Remote Interpreting (VRI) allows deaf or hard-of-hearing people who use sign language to communicate with hearing people in the same room. VRI addresses one limitation to VRS, which is that VRS cannot be used if the hearing person is in the same room with the deaf or hard-of-hearing person. VRI has proven to be useful for deaf or hard-of-hearing people in business meetings, doctor appointments, minor surgical procedures, and court proceedings.