What is a TTY / TDD?


The telephone is a vital element in our daily living. We routinely use the phone to chat with friends, make dinner reservations, inquire about job openings, and even to do our banking. For most of us, the telephone provides a convenience that we take for granted.

However, for the several million people in this country who are deaf, the conveniences as well as life-saving capacities of the telephone have, until recent years, been inaccessible. Today, a person who is deaf or speech impaired can make telephone calls using a TeleTYpewriter (TTY) or Text Telephone.
It is also sometimes called a TDD, or Telecommunication Device for the Deaf. TTY is the more widely accepted term, however, as TTYs are used by many people, not just people who are deaf.

A TTY is a special device that lets people who are deaf, hard of hearing, or speech-impaired use the telephone to communicate, by allowing them to type messages back and forth to one another instead of talking and listening. A TTY is required at both ends of the conversation in order to communicate.

Some TTYs are now equipped with both Baudot and ASCII. Baudot is the communication code used by TTYs, and ASCII is the code used by computers. A TTY equipped with ASCII allows the user to call any computer that has a telecommunication set-up. If the TTY does not have ASCII, the computer must have a special modem to translate the Baudot code.

To use a TTY, you can set a telephone handset onto special acoustic cups built into the TTY (some TTY models can be plugged directly into a telephone line or cell telephone). Then, type the message you want to send on the TTY's keyboard. As you type, the message is sent over the phone line, just like your voice would be sent over the phone line if you talked. You can read the other person's response on the TTY's text display.

If you don't have a TTY, you can still call a person who is deaf, hard of hearing, or speech-impaired by using a Telecommunications Relay Service (TRS). With TRS, a special operator types whatever you say so that the person you are calling can read your words on his or her TTY display. He or she will type back a response, which the TRS operator will read aloud for you to hear over the phone. Toll free TRS services are available 24 hours a day, 365 days a year.

To contact the Texas Center for Disability Studies by TTY, call us at (512) 232-0762. For persons using TTYs, you may also contact us through Relay Texas at (800) RELAY-TX. For persons with speech disabilities, please contact us through Speak-Up Texas at 1-8-SPEAK-UP-TX

We thank and acknowledge www.abouttty.com/ as well as www.adcohearing.com for information found on this page