UPDATED: March 29, 2016 Title has been renamed to reflect the original submission.
I received a submission of a guest post from Jason from Montana, edited by your humble curator kinda out of the blue. I did a pretty brief post on TTY a couple weekends ago and was surprised that I’d get a response, and got more insight to the TDD use of TTY. I’ve been meaning to post this subject for a while. Anyways the rest of the post is from him.
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Yup, it’s true, the deaf can use the phone. And ironically, they’ve been able to for many years. The Telecommunications Act of 1982 “allows states to require carriers to continue providing subsidies for specialized equipment needed by persons with impaired hearing, speech, vision, or mobility”.
The TTY device introduced in the 1970’s used the Baudot protocol to transmit text over standard telephone lines. They’re actually primitive modems in the sense that TTY’s use Frequency Shift Keying to have a tone match the character typed on the keyboard. Baudot runs very slow by comparison at only 50 baud. Most TTY’s have a character buffer so one can type faster than 50 baud, and the TTY will transmit as fast as it can. For someone who types 120 wpm, reading or typing a TTY conversation is painfully slow. By comparison, excluding compression, at the end of the dial up internet era most modems could do 56k, or 56000 baud. On the other hand, the phone lines don’t need to be very clean or clear to keep up with Baudot. Also, the conversation was simplex, meaning only one party could communicate at a time. TTY didn’t have any advanced algorithms to enforce this, so it was up to the users to clearly delineate when they were done typing by using the phrase SK (stop keying). This Wikipedia article (use with caution) has 3 fairly believable sample conversations.
Enter the relay service. Thanks to Title IV of the Americans with Disabilities Act (1990) all states must provide relay service.
The relay uses an operator to “translate” between the TTY user and a hearing individual on the other end of the line. See this video for a good demonstration. TTY Relay is free to the user, the service is paid for by a tariff paid on all telephone lines, regardless of the line owner is a TTY user or not. On my bill, this is denoted by “State Telecommunications Relay Service Charge”. Similar to 911, this service is accessed nationwide by special code 711. Relay services also offer VCO (Voice Carry Over) and HCO (Hearing Carry Over) where the user can either hear the caller (if they can’t speak) or speak to the caller (if they can’t hear) with the other half of the conversation being carried on the TTY.
While I can’t find a law mandating that businesses directly support TTY without using a relay, many businesses choose to support it and often publish a dedicated number for TTY calls. My personal experience at my business is that we would only handle about 1 legitimate TTY per year. The others that would ring the TTY line would either be misdials or fraudulent callers. Given this low volume, it was difficult to keep call center representatives knowledgeable about the proper operation and etiquette of the TTY device. To this end, we decided to record a TTY announcement on our TTY line advising the caller to use the relay service to call our regular voice number. I think most deaf callers would agree that the customer service is better this way because the relay operator is used to the TTY, and the call center agent can focus on serving the customer best without the additional distraction of the TTY.
A more modern version of the relay service is VRS or Video Relay Service and this is paid for by the deaf user on subscription. A video camera mounts above the TV and the relay operator uses sign language to interpret the conversation in a similar fashion to the TTY. Most of these video units can also make point-to-point calls to allow the deaf to communicate with each other without having the relay involved. I would imagine with technologies like FaceTime, deaf-to-deaf calls with a video unit are becoming more scarce.
Finally, in my experience, the mobile explosion that has taken place in the last few years has rendered the TTY mostly obsolete. The deaf can communicate with hearing people via SMS, iMessages and similar technologies just as if they were hearing. Most of the deaf I know carry a smartphone, they just never make calls with it!
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