Giving Speechless People a Unique Voice
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Complications after surgery left film critic Roger Ebert without a voice. To communicate, he used the text-to-speech program designed for Apple computers
Perhaps the two most famous speechless individuals are physicist Stephen Hawking and the late Robert Ebert, a film critic. To communicate with other individuals, both men used computers that generated synthesized voices, which sounded tinny, stilted and unnatural.
Now new technology could give speechless people a natural voice as unique to them as voices are to people who can speak.
“Right now, people who need to use synthesized voices to talk for them use a handful of generic voices, because creating them is time-consuming and costly,” said Rupal Patel, Ph.D, associate professor at Northeastern University. “We feel strongly the voice from the device should reflect something about that individual.”
With that philosophy, Patel, along with her research and development partner Tim Bunnell, Ph.D., a professor at the University of Delaware, developed VocaliD, a product that blends real human voices from healthy talkers with characteristics of the client’s unique speech patterns. The technique, called voice morphing, enables Patel and Bunnell to create a voice that is unique to the individual, and no longer has the now-traditional computerized sound.
The technology has positive implications for individuals who are autistic, or who suffer from disorders such as ALS or stroke, Patel said.
“There’s a relatively broad market of two-and-a-half to three million people who use devices to talk for them,” said Patel. “We’d love to see this technology being available to that population. We feel that if we can personalize the device, they will be more likely to use it and more socially acceptable.”
The technology is based on the fact that even speechless individuals can still make sounds, Bunnell said.
Famed physicist Stephen Hawking was diagnosed with a motor neuron disease when he was 21 years old. He has used a speech-generating machine to communicate since the 1980s.GEOFF ROBINS/AFP/Getty Images
“We can always grab characteristics of their voice and reapply the process as they go along,” he said. “With individuals who have neuro-degenerative diseases such as ALS, we capture speech from them right after they’re diagnosed, while they’re still speaking fluently and create their new voice from that. It captures elements of their voice that default devices don’t typically use.”
VocaliD was developed as an extension of another product called Model Talker, a text-to-speech synthesis system developed by Bunnell. A goal of VocaliD is to personalize the speech so that not only is the voice unique, but all vowels and consonants are clearly understandable.
Right now, although the technology is already developed, it is primarily a windows-based software product. Further development will enable the product to be used on I-devices (I-Phone, I-Pad).
“Making that happen is really more of an engineering kind of feat,” said Patel, who is cross-appointed in speech and language pathology, computer science and engineering. “What we’re doing here is manipulating the voice. There are no other labs doing this kind of work, although there are other efforts in trying to build voices. But they are categorically different because we are using a small amount of speech from our target talker.”
In addition to creating voices for speechless individuals, Bunnell sees other long term applications for VocaliD.
“It has lots of possible applications,” he said. “Those include things like rapidly developing multiple voices for games, or voices for reading books or novels. Right now the quality of the voices is still variable. Sometimes we are able to produce very good sounding voices and sometimes we can’t. We are still trying to work that out. This is an ongoing research project.”
Ultimately, users will likely be able to communicate in their own unique voices, from mobile communication devices as compact as a cell phone.