Captioned Telephone is similar to captioned television, where spoken words appear as written text for viewers to read.

The Captioned Telephone looks and works like any traditional phone, with callers talking and listening to each other, but with one very significant difference: captions are done live for every phone call.

The captions are displayed on the phone's built-in screen so the user can read the words while listening to the voice of the other party.

If the CapTel user has difficulty hearing what the caller says or understanding the words, he can read the captions for clarification.