Delayed auditory feedback devices play a stutterer's speech back to him

Monday, December 20, 2010; 6:59 PM

In the field of stuttering treatment, it has long been known that singing, imitating other speakers, speaking in unison with others - such as by reciting the Pledge of Allegiance - or even just paying attention to background chatter at, say, a cocktail party, can all promote fluency.

These concepts are the basis of a technology called delayed auditory feedback, or DAF. DAF devices are hearing-aid-like gadgets that play the stutterer's speech back to him, sometimes in a slightly altered form, after a split-second delay. The devices, which cost about $4,000 to $5,000, have gained in popularity over the past 15 years.

John Haskell, a speech therapist in New York who works with a variety of DAF devices, says that while it's not a magic pill, DAF can be effective if used as an adjunct to more-traditional speech therapy such as breathing exercises.

"Stuttering is largely a problem of timing," he said. "The signals from the brain to the vocal cords and the breathing mechanisms are off. They have to be coordinated; the person has to slow down. DAF does this for you."

When I tried the device, it was difficult, at first, to speak. I found that if I didn't slow my speech rate drastically - waiting for the device to play my last sentence back before starting the next - I would get tripped up. Haskell told me this is normal for people with no stutter or little stutter; for them, DAF tends to cause a stutter.

I understood how DAF might work for many stutterers, particularly people with severe cases, though it was strange to hear not only my own sentences played back but also the sentences of those around me. It reminded me of the way hysteria is depicted in movies: voices inside the head. For these reasons and others, not everyone is bullish on DAF, including Jane Fraser, the president of the Stuttering Foundation, who claims that DAF is impractical for everyday use.

- Dan Slater

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