Physicist Stephen Hawking has long dealt with a degenerative disease that leaves him unable to speak. Instead, he uses a speech synthesizer that bellows out his words in a now-recognizable robotic male voice. It works for Hawking—he's an adult male. But similar robotic voices are used for little girls and all the other 2.5 million Americans unable to talk. These people would speak in dramatically different vocal registers if they had the ability.
At this month's TEDWomen event in San Francisco, speech scientist Rupal Patel unveiled VocaliD, a project that will create prosthetic voices that actually sound like the people who use them. It could be a life-changing development in the robo-voice world.
"We wouldn’t dream of fitting a little girl with a prosthetic limb of a grown man. So why then the same prosthetic voice?" she asked onstage.
To create a prosthetic voice, Patel and her team at Northeastern University gather as many acoustical properties as they can from the person being fitted with the voice (that is, all the sound they're still able to produce) and overlay those properties on a voice from a surrogate voice donor who is the same gender, size, and age. A voice donor typically spends three to four hours reciting phrases that cover all the combinations of sound present in a language.
During her presentation, Patel imagined what the technology might mean for a little voiceless girl that she called "Samantha. "Samantha's voice is like a concentrated sample of red food dye that we infuse into a surrogate to get a pink voice," she said. "It sounds like her." With Patel's process, little girls sound like little girls and grown men still sound like grown men.
When generic robo-voices have been abolished, the voiceless will all sound more human, and less like robots devoid of personality. But Patel's project, funded by grants from the National Science Foundation, is still in its infancy—and it needs volunteer voice surrogates who are willing to give up a bit of time in exchange for being part of someone's speech. Voice donors can sign up here.