Hearing with your skin

We don’t just use our ears when we hear, but also our skin. The two senses work together to help us hear.

Through research, scientists at the University of British Columbia and at Haskins Laboratories, a speech research think tank in New Haven, Conn. have found that they can influence what people hear by delivering puffs of air to the back of the hand or neck.

The experiment

In the experiment, subjects heard the sounds “pa” or “ba” and “ta” or “da”. Sometimes, when the words had an aspirated sound – “pa” or “ta” – that requires the speaker to expel a puff of air, they received a puff of air on the back of their hand or neck. At other times, they got the reverse: a puff of air when they heard “ba” or “da” – non-aspirated sounds.

The researchers found that when the puff of air was paired with an aspirated sound, people were better at identifying the sound they heard. When the puff of air was paired with “ba” or “da”, accuracy declined.

In a previous study, Finnish researchers have used brain imaging to study 13 test subjects. They found that touch activated the auditory cortex, the part of the brain that is involved in hearing.

New ways of hearing

By demonstrating that the perception of speech is affected by touch, the experiment raises the possibility that one sense could be used as a substitute for another, creating new ways for the hearing impaired to hear. Study leader Dr Bryan Gick said his team would now work to develop a hearing aid which incorporates these findings.

“All we need is a pneumatic device that can produce air puffs aimed at the neck at the right times, based on acoustic input into the hearing aid, and then a set of experiments to test its efficacy.”