Real-Time Text (RTT) transmits text as someone types it. It takes only a fraction of a second to send the characters. They display immediately to the receiving person(s) as well. In other words, the receiving person(s) is able to read the text as the sender types it. In this way RTT has the same conversational directness and interactivity as voice. RTT is of particular importance for people with hearing loss and people who are Deaf. However, there’s anticipation that mainstream users will adopt RTT as well. It’s a convenient tool, because you don’t need any specialized devices.
RTT is a natural replacement or extension for other real-time, conversational services like voice calls. For example, you can use it in noisy environments. In addition, you can use it to communicate during a meeting when voice is not appropriate. It is also a very useful way to convey information where numbers, street addresses or exact spelling are important. It is also helpful for words that are hard to perceive because of different dialects.
Tips for using RTT during a call
- The text that you enter appears to the other person in real-time, unlike with standard text messaging. Therefore, if you make a mistake and then delete it, the other person can see the mistake and the deletion.
- You can use RTT to call emergency services.
- RTT calls include an audio stream. To mute or un-mute your microphone, tap Mute .
- You can have multiple RTT calls going at the same time.
- If the other person on the call does not have RTT, it is a voice only call.
- Calls do not include audio if both devices have RTT enabled when a call starts. You can press the microphone icon to enable simultaneous voice and text.
- If you aren’t hearing audio on a call and need it, try turning RTT off.
Consistency with other real-time multimedia
RTT is useful as a stand-alone feature. It also works in conjunction with other real-time features such as voice calls and video conferencing. RTT enhances the effectiveness of these other modes of communication. RTT also allows you to combine voice and text calls. For both incoming and outgoing calls that start as voice, you can upgrade to RTT. This will keep the microphone active. For calls started as RTT, if voice audio is off, you can tap the microphone icon to activate it.
Click for details on how to use RTT on an Android device.
Click for details on how to use RTT on an iPhone.
How to turn on RTT
- Navigate: Settings > Accessibility > Hearing enhancements.
- Tap Real-Time Text.
- Tap Always visible to turn the RTT keyboard on or off .
RTT vs TTY comparison
Here are some advantages of RTT over TTY:
- RTT is a newer technology with more advanced features than TTY.
- Unlike TTY, which requires users to take turns, with RTT both parties can send and receive text at the same time.
- RTT is more reliable than TTY, because nationwide phone networks carry the messages.
- RTT provides additional characters to choose from – international characters, emojis and the “@” symbol, for example.
- You can make RTT calls using just your mobile phone (as long as it is RTT-capable).
- Unlike TTY, you don’t need a separate device to make RTT calls.
For more details, see this FCC information on RTT.