Mobile interpreter

Scientists from the University of Aberdeen in Scotland have announced the forthcoming release of the Portable Sign Language Translator (PSLT), a new software application that could be used to translate from various sign languages into written English through gesture recognition technology. The founders of Technabling, the Scottish startup behind the PSLT, say that they have been working on it for more than a year now, and hope to make it available by 2013.

To learn more, DW spoke with Ernesto Compatangelo, a lecturer in computing science at the University of Aberdeen and founder of Technabling.

DW: What exactly is the Portable Sign Language Translator?

Ernesto Compatangelo: Well, basically the PSLT is a software-based device that runs on a number of platforms, from smartphones to desktops and does exactly what it says in the title: it translates sign language into text. Any sentence that is signed is translated into a plain English sentence that appears on the device, or elsewhere.

So if I'm speaking to you in sign language and you have a PSLT in your hand, how would you use it?

Say you had an Android smartphone. You put the Android smartphone somewhere, you sign in front of it, and on the same side or on the opposite, you would see the text on the screen.

So what it's using is gesture recognition?

Yes. Gestures are recognized and depending on the sequence of gestures and the fact that you pause at the end of a signed sentence, then the English sentence corresponding to what you just said will appear immediately.

There are different sign languages all around the world. Which sign languages does your PSLT support for the time being?

We support a number of them. The PSLT can potentially accept any sign language. But you have to start somewhere and we started with British Sign Language and Makaton. [Ed: Makaton is an artificial language structure designed to help people with cognitive impairments communicate more effectively through pictographs, speech and gestures.]

But this is purely coincidental. The system is fully customizable. We load different libraries corresponding to different sign languages or different regional variations of sign languages.

Do you have any sense at this point as to how this would become available or how much it would cost?

It's very likely we will make it available for download. In terms of costs, we haven't decided yet, but in terms of customer base, we definitely want to make it something affordable. So we're not talking about hundreds and hundreds of pounds.

At the moment the cheapest smartphone is about 100 pound or 100 euros ($130), and we think our device shouldn't be more than that. We're also exploring alleys where our device could be provided by the National Health Service or other health care services and so it would be provided for free.

With machine translation, like we would use with Google Translate, it takes many many blocks of text that have been translated by a human from a source language into a target language, and then scans those texts to determine rules as a way to generate new translations.

The way sign language is translated into text is a slightly different thing. If you take a spoken language, say German, into a another language, say English, you have roughly the same expressive power. It's just a way of expressing the symbols, and the grammar is different but the expressive power is similar. Sign languages are much less expressive than written or verbal language, and so on top of the translation we have a process of enrichment, so beefing up the whole thing.

So a typical example, if in sign language you want to say, "Tomorrow I will have to go to the supermarket to buy some food," the way you would sign it is something like, "tomorrow, me, go, supermarket, buy, food." But you understand that the expressiveness is just not there. Tenses are not there, articles are not there. Once you get the set of signs, you have to do a more sophisticated work of interpolation, so you have to add the right tenses and the right articles to make sure that what comes out is perfect English so that it's not something that sounds funny or incomplete.

Interview: Cyrus Farivar
Editor: Holly Fox