A remote interpreter wearing a headset smiles as they interpret for a deaf individual using a TTY device.

Unlocking Communication: 7 FAQs about Teletypewriter (TTY) Devices and How They Work

We are embarking on a journey into a topic that often leaves people with questions: the TTY (teletypewriter) device.

While many people have heard of TTY, not everyone fully understands its significance or how, exactly, it works.

As we tackle some of the most frequently asked questions we get on this topic, we’ll dive into TTY, its function, how to use it, and how it bridges the communication gap with individuals who rely on different forms of assistive technology.

Even if you’re familiar with TTY, you just might learn a thing or two . . .

TTY and the Relay Service Connection

So what is TTY?

A TTY (teletypewriter) device is a text communication tool designed for individuals who are deaf, hard of hearing, or have speech impairments. It features a keyboard and screen, allowing users to type messages that are transmitted over telephone lines. TTY users can communicate with voice callers this way.

Many modern cell phones also have a built-in TTY mode or TTY compatibility option.

Can anyone call a number connected to a TTY device?

You bet! TTY devices are designed to work with standard telephone lines, so anyone with a regular telephone can call a TTY number. (A “TTY number” is another way to say a phone number connected to a TTY device.) 

See also: 9 Terms You Need to Know about Effective Communication for Your Deaf Customers

Do I need a TTY device to call a TTY number?

Nope. When someone without a TTY device calls a TTY number, the call is typically routed through a relay service. The relay service acts as an intermediary, typing out your spoken words to the TTY user and reading out the TTY user’s typed responses back to you.

If I call a TTY number from a standard phone, will I be connected to a relay service first?

Yes. When you call a TTY number, a relay service operator will answer the call first and identify themselves. You can then provide the operator with the TTY number you wish to call. The relay service operator will guide you through the process, ensuring a seamless conversation with the TTY user.

How can I tell if the number I’m calling is a TTY phone number?

Determining if a number you’re calling is a TTY number might not always be straightforward. You can look for indicators like “TTY,” “TDD,” or “Text Telephone” labels in directories or listings. If unsure, you can call the number anyway; if it’s a TTY number, you’ll likely connect to a relay service operator for assistance. 

Asking the person directly and being open to various communication methods like video relay services, text messaging, and communication apps can also help you communicate effectively with individuals who rely on different types of tools.

Do I have to pay extra fees to call a TTY phone number?

Nope. In the U.S., relay services (including TTY) are provided for free to all users.

Do I have to call my language services provider before dialing a TTY phone number?

Not at all! Go ahead and dial the number. (And see above for what will happen when you do!)

Related: Know the Laws for Using ASL Video Interpreters

Embracing Diverse Communication Methods

By understanding how TTY works, embracing new communication methods, and being open to new experiences, we can create a more inclusive and accessible world for everyone. So the next time you come across a TTY number, remember that you have the power to connect, communicate, and foster understanding. 

And harnessing tools like TTY can be the key to that connection.


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