Researchers have developed a new technology that helps Parkinson's patients overcome the tendency to speak too quietly by playing a recording of ambient sound, which resembles the noisy chatter of a restaurant full of patrons.

"People with Parkinson's disease commonly have voice and speech problems," said Jessica Huber, an associate professor in Purdue's Department of Speech, Language and Hearing Sciences.

Parkinson's affects 1.5 million people in the United States and is one of the most common degenerative neurological diseases. About 89 percent of those with Parkinson's have voice-related change, which is related to how loudly they speak, and about 45 percent have speech-related change, or how clearly they speak.

"A major therapy is to get people to speak louder, which also may cause them to articulate more clearly," Huber said.

The most common therapy, the Lee Silverman voice treatment program, trains patients to speak louder in one-hour sessions four days a week for a month.

"Some Parkinson's patients do great with this approach, but others do not," Huber said. "They forget to keep speaking louder the minute they have left the therapy room. Lee Silverman tends to work less for people with later stages of disease or those who have some cognitive decline. So I wanted to know whether there was an easier way to cue people during therapy, rather than telling them, 'Try to be twice as loud,' or 'Try to focus on this sound meter and achieve this loudness.'"

Huber used a new approach: The patients were asked to speak louder while a recording of background "multitalker babble noise" was played. The noise is essentially the sound of a restaurant full of patrons, but without the clattering silverware and clinking glasses.

"They had an easier time getting louder when I had the noise in the room," she said. "Ordinarily, when I asked them to be twice as loud they would say they couldn't. They couldn't speak 10 decibels louder, but when I turned on the babble noise, they spoke over 10 decibels louder."

The background sound elicits a well-known phenomenon called the Lombard effect, a reflex in which people automatically speak louder in the presence of background sound.

"You go into a loud room at a party and you talk louder without even realizing it," Huber said. "We've all had the experience where the room suddenly gets quiet and you're still shouting but you didn't know you were."

Huber created a new electronic technology using this principle. The voice-activated device automatically plays the background babble when the person begins to speak. A sensor placed on the neck detects that the person has begun to speak and tells the device to play the babble through an earpiece worn by the patient.

"Jessica Huber, at left, an associate professor in Purdue's Department of Speech, Language and Hearing Sciences, and graduate student Meghan Moran demonstrate a new technology developed in Huber's lab that helps Parkinson's patients overcome the tendency to speak too quietly. The system works by playing a recording of ambient sound, which resembles the noisy chatter of a restaurant full of patrons. A sensor placed on the neck detects that the person has begun to speak and tells the device to play the babble through an earpiece worn by the patient. Patients also wear a mask and sensors in elastic bands placed around the rib cage to precisely record respiratory, laryngeal and articulatory data. (Credit: Purdue University photo/Andrew Hancock)"

Source: Purdue University