Someone's Breath on Your Neck Makes you Hear Better

DEPENDING on whose it is, breath on your neck may or may not feel good. Either way, now it seems that it can help you understand what someone is saying. The discovery could lead to hearing aids that emit puffs of air.

We know that what we see affects what we hear. For example, if we hear "ba" while watching a person saying "ga" we think we've heard "da". Bryan Gick and colleagues at the University of British Columbia in Vancouver, Canada, wondered whether tactile sensations affect hearing too.

In speech, the "aspirated" syllables "pa" and "ta" are accompanied by a puff of exhaled air, whereas "ba" and "da" are not. Such puffs aren't always detected when someone is speaking, but Gick's team reasoned that the brain might learn to use puffs to modify its perception of certain sounds.

They had 66 volunteers listen to a male voice saying all four syllables against background noise that made it hard to distinguish them. At the same time as some of the syllables, they delivered a puff of air to the hand or neck.

Although many volunteers could not consciously feel the puffs, they were still more successful at correctly identifying "pa" and "ta" when these sounds were accompanied by air puffs. In contrast, air puffs made it less likely that they would correctly identify "ba" and "da" and more likely that they would mistake these for sounds for "pa" and "ta" (Nature, DOI: 10.1038/nature08572).