Tactile input affects what we hear: study

November 30, 2009

Humans use their whole bodies, not just their ears, to understand speech, according to University of British Columbia linguistics research.

It is well known that humans naturally process facial expression along with what is being heard to fully understand what is being communicated. The UBC study is the first to show we also naturally process tactile information to perceive sounds of speech.

Prof. Bryan Gick of UBC's Dept. of Linguistics, along with PhD student Donald Derrick, found that air puffs directed at skin can bias perception of spoken syllables. "This study suggests we are much better at using tactile information than was previously thought," says Gick, also a member of Haskins Laboratories, an affiliate of Yale University.

The study, published in Nature today, offers findings that may be applied to telecommunications, speech science and hearing aid technology.

English speakers use aspiration - the tiny bursts of breath accompanying speech sounds - to distinguish sounds such as "pa" and "ta" from unaspirated sounds such as "ba" and "da." Study participants heard eight repetitions of these four syllables while inaudible air puffs - simulating aspiration - were directed at the back of the hand or the neck.

When the subjects - 66 men and women - were asked to distinguish the syllables, it was found that syllables heard simultaneously with air puffs were more likely to be perceived as aspirated, causing the subjects to mishear "ba" as the aspirated "pa" and "da" as the aspirated "ta." The brain associated the air puffs felt on skin with aspirated syllables, interfering with perception of what was actually heard.

It is unlikely aspirations are felt on the skin, say the researchers. The phenomenon is more likely analogous to lip-reading where the brain's area activates when the eyes see lips move, signaling speech. From the brain's point of view, you are "hearing" with your eyes.

"Our study shows we can do the same with our skin, "hearing" a puff of air, regardless of whether it got to our brains through our ears or our ," says Gick.

Future research may include studies of how audio, visual and tactile information interact to form the basis of a new multi-sensory speech perception paradigm. Additional studies may examine how many kinds of sounds are affected by air flow, offering important information about how people interact with their physical environment.

Source: University of British Columbia (news : web)

Explore further: Mapping the selective brain

Related Stories

Mapping the selective brain

November 21, 2007

Researchers have added a new piece to the puzzle of how the brain selectively amplifies those distinctions that matter most from the continuous cascade of sights, sounds, and other sensory input. Whether recognizing a glowering ...

Where the brain makes sense of speech

December 19, 2007

Researchers have identified regions of the brain where speech sounds are perceived as having abstract meaning, rather than as just a stream of sensory input. They said their identification of the regions demonstrates that ...

Our faces, not just our ears 'hear' speech: study

January 20, 2009

(PhysOrg.com) -- A McGill-led study has found that the perception of speech sounds is modified by stretching facial skin in different directions. Different patterns of skin stretch affect how subjects perceive different words.

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.