Hearing Through the Skin

Evidence that we use both eyes and ears to hearcues to figure out what is being said to them.
has been around since the mid 1970s, now a newGetting a sense of a full picture of how sound is
Canadian study out of the University of Britishbuilt might prove helpful in the development of
Columbia finds that inaudible puffs of air deliveredcommunication aids for the hearing impaired. In
along with certain sounds has an influence on whatfact, Dr. Gick, the leader of the study, plans to
subjects thought they were hearing.work on developing a hearing aid that incorporates
According to associate professor of linguisticsthese findings. "All we need is a pneumatic device
Bryan Gick and graduate student Donald Derrick,that can produce air puffs aimed at the neck at
audio and visual clues are just part of the storythe right times based on acoustic input into the
as tactile sensation also affect how sound ishearing aid, and then a set of experiments to test
heard. The work appears in the November 26,the efficacy."
2009 issue of the journal Nature.The idea that a small puff of air on the skin could
Strange to think we may actually hear with ourhelp the hearing impaired distinguish consonants
skin.like "b" and "p" or "t" and "d" that have the same
Science already knows that visual clues that comelip pattern fascinated researchers. If more work
from a speakers face can enhance (or interfere)shows the same effect is seen when listening to
with how you hear what's being said to you.everyday speech, then it really could help create
Normally when we say words with the letters "p",better hearing aids.
"t" and "k" we produce a puff of air (so small itsIt's also quite intriguing that our brains can be
rarely felt or noticed), and this is another clue thataffected by a puff of air that most don't hear
lets the listener tell the difference between wordsand few of us realize we produce when speaking.
with these letters from those with similarFunny how our complex brains can be fooled by
sounding letters like "b", "d" and "g".something as simple, as weightless and unseen as
For the current work, the team compared soundsa whiff of air.
accompanied by a small inaudible breath of air -We know that the eyes can fool the ears due to
sounds such as "pa" and "ta" while also usinga particular phenomenon called the McGuirk Effect,
sounds that aren't (such as "ba" and "da").where subjects can be fooled into thinking they're
At the same moment they heard the recordedhearing "da" when they're truly hearing "ba" as
sounds, the subjects were either given, or not, athey see a face mouthing the syllable "ga".
small puff of air to the neck or the back of theOne theory that might explain this illusion is that
hand.the brain goes through a lifetime of learning to put
Researchers noticed that "ba" and "da" (known astogether sound and visual information to
unaspirated sounds) were heard as the aspiratedunderstand the spoken word - getting fooled
equals "pa" and "ta" when accompanied by thewhen the information doesn't match, as we see
puff of air.with the McGuirk Effect.
It's the air that distinguished the sounds, andThe research suggests that this integration of
though we're used to the hearing side, we're notdifferent senses in speech may not be something
used to feeling that puff of air on our skin.people learn though experience, but that an
This is what suggests to researchers that peopleentirely different processes may be going on.
use tactile sensory information along with other