Engineering prosthetic voices

by Angela Herring

"Never heard me before." That's what William, a 9-year-old boy with a speech-language disorder, said the first time he used the prosthetic voice that Northeastern associate professor Rupal Patel made just for him.

In San Francisco on Thursday, Patel, who has joint appointments in the Bouvé College of Health Science and the College of Computer and Information Science, shared William's story with thousands of viewers at TEDWomen, a two and a half day conference organized by the nonprofit organization TED, devoted to "Ideas Worth Spreading." This year's TEDWomen focused on invention in all its forms. Patel's talk was livestreamed for a group of Northeastern students, faculty, and staff gathered at the Behrakis Center.

There are 2.5 million Americans like William who are unable to speak, Patel told the audience, and many of them use the same computerized voice to communicate. "That's millions of people worldwide who are using generic ," she said.

So much of our personality is contained in our voice, Patel explained. Even though people with speech-language disorders retain the ability to control that element of speech that is critical for determining individuality, a grown man may still have the same prosthetic voice as a young girl.

Through a project launched simultaneously with her TEDWomen talk, Patel is trying to change that. She and her team at Northastern's Communication Analysis and Design Laboratory have developed a technology called VocaliD (voh-CAL'-ih-dee) that allows them to create prosthetic voices that sound like the people with the speech impairments they were designed for. As William's mother put it, "This is what William would have sounded like had he been able to speak," Patel told the audience.

To create these voices, VocaliD extracts acoustic properties from a target talker's speech—whatever sounds they can still produce—and applies these features to a synthetic voice that was created from a surrogate voice donor who is similar in traits such as age, size, and gender. What is produced is a containing as much of the vocal identity of the target talker as possible yet the speech clarity of the surrogate talker.

By mixing the person's voice with that of a surrogate talker who has donated hours' worth of recorded sentences, the team can parse these sentences into "small snippets of speech" that can be reassembled into any other combination of words.

What happens next has been described by Patel's own daughter as "mixing colors to paint voices." William's vowel sound, for example, acts like a concentrated drop of red food dye. This is then mixed with the recorded speech snippets and infuses each of them with his unique vocal identity.

"So far we have a few surrogate talkers from around the U.S. who have donated their voices," she said. "We have been using and reusing them to build our first few personalized voices. But there's so much more work to be done."

With VocaliD.org, Patel has created a crowd-sourced portal for people around the world to donate their voices to the voiceless.

"We wouldn't dream of fitting a little girl with a prosthetic limb of a grown man," Patel said. "So why then the same prosthetic voice?" With VocaliD, that's longer necessary, she said.

More information: vocalid.org/

add to favorites email to friend print save as pdf

Related Stories

Researcher gives subjects their voice

Feb 21, 2013

Stephen Hawking and a 9-​​year-​​old girl with a speech dis­order most likely use the same syn­thetic voice. It's called Per­fect Paul and it's easy to under­stand, espe­cially in acousti­cally ...

For child readers, 'once more with feeling'

Jun 24, 2010

(PhysOrg.com) -- Rupal Patel, an associate professor of speech-language pathology and audiology at Northeastern, is developing innovative reading software that helps youngsters learn to read aloud with more ...

Voice prostheses can help patients regain their lost voice

Oct 24, 2012

Help is on the way for people who suffer from vocal cord dysfunction. Researchers are developing methods that will contribute to manufacturing voice prostheses with improved affective features. For example, for little girls ...

Speech Synthesizer Helps Movie Critic

Jun 15, 2010

The voices you hear on message services are often created artificially by fitting together short audio snippets from a large library of vocalized words and sounds. Scientists are now moving beyond the older ...

Recommended for you

Exploring 3-D printing to make organs for transplants

19 hours ago

Printing whole new organs for transplants sounds like something out of a sci-fi movie, but the real-life budding technology could one day make actual kidneys, livers, hearts and other organs for patients ...

High frequency of potential entrapment gaps in hospital beds

21 hours ago

A survey of beds within a large teaching hospital in Ireland has shown than many of them did not comply with dimensional standards put in place to minimise the risk of entrapment. The report, published online in the journal ...

Key element of CPR missing from guidelines

Jul 29, 2014

Removing the head tilt/chin lift component of rescue breaths from the latest cardiopulmonary resuscitation (CPR) guidelines could be a mistake, according to Queen's University professor Anthony Ho.

Burnout impacts transplant surgeons (w/ Video)

Jul 28, 2014

Despite saving thousands of lives yearly, nearly half of organ transplant surgeons report a low sense of personal accomplishment and 40% feel emotionally exhausted, according to a new national study on transplant surgeon ...

User comments