Tty\tdd- A text-telephone device (TTY) used by individuals who may have deafness, other hearing difficulties, or speech disabilities. The Telecommunication Relay Service (TRS) is a free service that enables persons who are deaf, hard-of-hearing or speech-impaired to use their TDD or TTY to place calls to and receive calls from hearing people. It also enables hearing people to call TDD/TTY users. To use TRS dial 711 (just like you would dial 911 for an emergency). Typed messages from a TDD/TTY are transmitted to a communication assistant who voices them to hearing persons. Hearing persons' messages are voiced to the communication assistant who relays them to the TDD/TTY printout or display. Calls can be placed 24 hours a day, seven days a week. There are no limits to the length or number of calls. All calls are confidential. Long distance calls are placed at direct dial rates. If you are a registered TDD/TTY user, discount rates may apply for long distance calls. TTY/TTD users can communicate directly with other TTY/TTD users without using TRS. this feature is available on the iphone in the settings

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