Hearing with both your skin and your ears

Gick and Derrick offer a fascinating example of cross modal sensory perception, demonstrating 'aero-tactile' integration in speech perception:

...we show that perceivers integrate naturalistic tactile information during auditory speech perception without previous training. Drawing on the observation that some speech sounds produce tiny bursts of aspiration (such as English 'p'), we applied slight, inaudible air puffs on participants' skin at one of two locations: the right hand or the neck. Syllables heard simultaneously with cutaneous air puffs were more likely to be heard as aspirated (for example, causing participants to mishear 'b' as 'p'). These results demonstrate that perceivers integrate event-relevant tactile information in auditory perception in much the same way as they do visual information.

The syllables included “pa” and “ta,” which produce a brief puff from the mouth when spoken, and “da” and “ba,” which do not produce puffs. When listeners heard “da” or “ba” while a puff of air was blown onto their skin, they perceived the sound as “ta” or “pa.” It seems likely that this integration of different sensory cues is innate, for subjects were completely unaware that they were doing it.