RTT/TTY

How to Set Up and Use RTT and TTY on iPhone

If you have hearing or speech difficulties, you can use Teletype (TTY) or real-time text (RTT) to communicate on the phone. These protocols allow you to transmit text as you type and allow the recipient to read the message right away. RTT is a more advanced protocol that transmits audio as you type text.

iPhone provides built-in Software RTT and TTY from the Phone app, and it also supports Hardware TTY. The following steps will guide you on how to set up and use RTT and TTY on iPhone.

Set Up RTT and TTY

1. Go to Settings > Accessibility.
2. Click on RTT/TTY or TTY, and then choose a line if your iPhone has Dual SIM.
3. Turn on Software RTT/TTY or Software TTY.
4. Click Relay Number, then enter the phone number to use for relay calls using Software RTT/TTY.
5. Turn on Send Immediately to send each character as you type. Turn off to complete messages before sending.
6. Turn on Answer All Calls as RTT/TTY.
7. Turn on Hardware TTY.

Connect iPhone to an External TTY Device

If you turned on Hardware TTY in Settings, connect iPhone to your TTY device using the iPhone TTY Adapter. If Software TTY is also turned on, incoming calls default to Hardware TTY.

Start an RTT or TTY Call

1. In the Phone app, choose a contact, and then tap the phone number.
2. Choose RTT/TTY Call or RTT/TTY Relay Call.
3. Wait for the call to connect, and then tap RTT/TTY.
4. Enter your message in the text field.
5. If you turned on Send Immediately in Settings, your recipient sees each character as you type. Otherwise, click on the arrow pointing up icon to send the message.
6. To also transmit audio, click on the microphone icon.

Review the Transcript of a Software RTT or TTY Call

In the Phone app, click on Recents. RTT and TTY calls have the horizontal phone icon next to them. Next to the call you want to review, click on the icon with the “i” in a circle.

Use Cases

• RTT and TTY are useful for people who have hearing or speech difficulties, allowing them to communicate on the phone with others who are also using these protocols.
• Hardware TTY is helpful for those who prefer to use an external device to communicate on the phone.
• Send Immediately is useful for quick and efficient communication, while turning it off is helpful for editing and proofreading messages before sending.
• Answer All Calls as RTT/TTY is useful for receiving RTT/TTY calls without having to turn it on for each call.
• The transcript feature is helpful for reviewing previous conversations.