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What is TTY mode? Everything you need to know

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  • 3 min read

If you’ve been playing around in your phone’s settings, you must have come across quite a few settings you might not fully understand. One such mystery setting or feature is the TTY mode present on some phones.

In this article, we’re talking about what is TTY, and how to use TTY mode on your Android or iOS device and everything else you need to know. 

Also read: How to invert colours in Windows 10?


What is TTY?

TTY refers to a Teletypewriter. It’s a special device that helps hearing-impaired, speech-impaired or those hard of hearing, in general, to communicate using a phone. TTY devices are initially designed with landlines in mind; however, they work just fine with mobile phones these days. 

An early example of a Teletypewriter machine.

The teletypewriter converts words to audio signals and vice versa, much like the CC feature on TikTok, except much faster and more accurate. 

So if you’re typing a message on a TTY machine connected to your phone, it’ll automatically convert the words you’re typing into audio signals and send it over to your phone, which in turn will send the audio it receives over on the call. Inversely, if any audio is coming to the TTY from the phone, the machine will convert audio signals to words and show it on the machine.


What’s a TTY mode then?

TTY mode refers to a specific setting on your phone which makes it compatible with TTY machines. Now depending on your manufacturer, it might be hidden away somewhere in your phone’s accessibility settings or might be named something else, but some version of this feature will be on your phone. 

Similar settings such as TalkBack might also be at your disposal. These features work much like the Narrator on Windows — they say out words on your screen, which is especially helpful for the visually impaired.

Most phones will have three different TTY modes as follows:

  • TTY Full: This mode is for text-only communications both ways with no audio support.
  • TTY HCO: Stands for TTY Hearing Carry Over. In this mode your messages are sent via text but recieved via audio, much like a text to speech program. This feature is often used for the speech-impaired.
  • TTY VCO: Stands for TTY Voice Carry Over. In this mode whatever you talk is coverted to text on the teletypewriter and sent over on the phone call.

How to enable TTY Mode on your phone?

Follow these steps to enable the TTY Mode on your Android or iOS device.

Enable TTY on Android

  • Head over to your phone’s settings and find Call.
  • Scroll down to find the TTY Mode setting and tap to enable the feature. You can select the desired TTY mode from here as well.

Enable TTY on iOS

  • Head over to the phone settings and tap General.
  • Tap Accessibility to proceed.
  • Select TTY. You can select whether you’d want to use Software TTY built into the phone or Hardware TTY if you’ll be attaching a TTY device.

From here on, you can tap the TTY button anytime you call someone and enable the feature. Do keep in mind that there might be a drop in call quality when the feature is active.

Also read: Top 7 text-to-speech apps for Android

Yadullah Abidi

Yadullah Abidi

Yadullah is a Computer Science graduate who writes/edits/shoots/codes all things cybersecurity, gaming, and tech hardware. When he's not, he streams himself racing virtual cars. He's been writing and reporting on tech and cybersecurity with websites like Candid.Technology and MakeUseOf since 2018. You can contact him here: yadullahabidi@pm.me.

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