The race to teach sign language to computers

USING A computer used to mean bashing away at a keyboard. Then it meant tapping on a touchscreen. Increasingly, it means simply speaking. Over 100m devices powered by Alexa, Amazon’s voice assistant, rest on the world’s shelves. Apple’s offering, Siri, processes 25bn requests a month. By 2025 the market for such technology could be worth more than $27bn.

One group, though, has been left behind. The World Health Organisation counts 430m people as deaf or hard of hearing. Many use sign languages to communicate. If they cannot also use those languages to talk to computers, they risk being excluded from the digitisation that is taking over everyday life.

Many have tried to teach computers to understand sign language. There have been plenty of claims of breakthroughs in recent years, accompanied by so-called solutions ranging from haptic gloves that capture the wearer’s finger movements to software that detects distinct hand shapes. Many of these have won acclaim while alienating the very people for whom they are ostensibly designed. “The value for us basically is zero,” says Mark Wheatley, the executive director of the European Union of the Deaf (EUD).

It is easy to see why. Gloves are intrusive, as are similar technological solutions such as body-worn cameras. Both require users to adapt to the needs of hearing...