Best Answer

TTY is an abbreviation for TeleTypewriter. It's a device used by the deaf to "text" messages across an analog telephone line. These days, text messaging has just about obsoleted the device however it remains well-suited to the task.

Because the TTY was originally designed for an analog phone system it worked very much like an analog modem; converting "text" into "sounds" that were then re-interpreted back into text at the receiver's end. Both parties of the conversation would have to have a TTY machine.

This adapter allows a person to connect a TTY machine to the "analog" audio input and output of the phone.

• Answered by EP from Dunedin
• 25-Nov-2009
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