What is a captioned telephone?

A captioned telephone is a phone service that shows the words of the person you are talking to as text on a screen while you listen. It covers phone calls. The guide to speech to text for deaf and hard of hearing people compares those built-in options. In federal rules the service is called IP captioned telephone service, or IP CTS. Its cost is paid from a federal fund, and only people with hearing loss may use it with captions turned on.

A captioned telephone adds a live text feed to a normal call

You keep talking and listening as you would on any phone call, and the other person's words appear as text. The most widely used form of IP CTS works through a person and a computer. The call is connected both to the other party and, over the internet, to a communications assistant. In the description the American Speech-Language-Hearing Association gives, the assistant repeats what the other party says, and voice recognition software turns the assistant's voice into text ¹. The text then goes to your phone or to the device you use for the call.

The service links the call and its captions over the internet. The same description says it can also be used as an app with a smartphone ².

Federal rules limit the service to people with hearing loss

The federal consumer notice that providers must give says that only registered users with hearing loss may use IP captioned telephones with the captions turned on ³. The captions are for people who cannot easily follow a conventional phone call, and the rules are written around that need.

Eligibility is described in general terms. ASHA says that anyone with hearing loss of sufficient degree that compromises successful use of a conventional telephone may be eligible ⁴. The same page says an FCC rulemaking to set IP CTS eligibility standards was underway when it was written ⁵, so check the current FCC rules before you apply. Because only registered users may use the service ³, you will need to register with a provider before you can use it.

Hearing loss is common in older adults. In the 2014 National Health Interview Survey, 43.2 percent of adults aged 70 and older reported trouble hearing ⁶, so older callers are one group who may need captions on calls.

The cost is paid from a federal fund, not by the minute

The required consumer notice says there is a cost for each minute of captions, paid from a federally administered fund ⁷. The rules also say the costs of IP CTS are recovered from all subscribers for every interstate and intrastate service ⁸, so the costs fall on subscribers in general rather than on each caller.

The FCC approved IP CTS as a form of relay service in 2007 ⁹. The same ASHA description says IP CTS calls may be compensated from the Interstate TRS Fund ¹⁰.

What to do if you want a captioned telephone

1. Confirm your hearing loss. The service is for people whose hearing loss makes a standard phone call hard, so think about the calls you cannot follow.
2. Compare providers. Check which devices each one supports, since the service can run on a computer or as a smartphone app ².
3. Register and check the current rules. You will need to register with the provider, and check the FCC's current rules, because the eligibility standards were under review when ASHA's page was written ⁵.
4. Test a call before you rely on it. Ask a family member to call you, and check whether the captions keep up with the speaker and whether you can follow the conversation.
5. Plan for calls that matter most. For a medical appointment or a legal call, ask whether a human captioner can join, since accuracy depends on the setting.

For captions in person rather than on the phone, see the question on speech to text glasses for deaf people. For how accurate automatic captions are in general, see whether AI captioning is accurate enough for deaf people. The overview of guides on accessibility is in the accessibility and health overview.