Telephone Equipment for the Deaf

Hearing loss has many causes; while some people are born deaf or hard of hearing, others lose their hearing as a result of illness, infection or inner-ear damage. Communicating face-to-face is done through speech therapy, lip reading techniques or by using sign language. Advanced technology allows the deaf and the hard of hearing to communicate by telephone.

TTY/TDD Devices

• TDD stands for "telecommunications device for the deaf" and is also known as a TTY machine, or teletypewriter. The earliest TTY/TDD was invented by Dr. James Marsters, a deaf orthodontist, along with deaf physicist Robert H. Weitbrecht and engineeer Andrew Saks. TTY/TDD devices allows deaf or hard of hearing people to communicate by written text transmitted over a telephone line.

Web Cameras

• The Internet has given deaf and hard of hearing individuals more freedom to communicate. Web cameras allow two people to communicate face-to-face, making it convenient for individuals who prefer to use sign language. With a good quality webcam, reading lips is also an option. If a hearing person is communicating with a deaf person, he can opt for an IP Video Relay Service, which uses an interpreter to translate speech into sign for the deaf user, and sign into speech for the hearing user.

Telephone/Telecoil Hearing Aid Switch

• Deaf or hard of hearing individuals who use hearing aids have the option of using a telephone or telecoil switch. The switch improves telephone sound quality by turning off the hearing aid's microphone, which eliminates the whistling sound created by feedback.

Voice Carry Over

• Deaf or hard of hearing individuals who do speak can also choose the Voice Carry Over system to communicate by telephone. An operator relays information to the deaf user by teletype, and the deaf user responds with her own voice.