We’re all familiar with the sensation of sound so loud we can actually feel it: the roar of a jet engine, the palpable vibrations of a loud concert, a thunderclap so close it shakes the windows. It may surprise you to learn, however, that that’s not the only way in which we “feel” sounds. In fact, recent research suggests that tactile information might be just as important as sound in some cases!
I’ve already talked about how we can see sounds, and the role that sound plays in speech perception before. But just how much overlap is there between our sense of touch and hearing? There is actually pretty strong evidence that what we feel can actually override what we’re hearing. Yau et. al. (2009), for example, found that tactile expressions of frequency could override auditory cues. In other words, you might hear two identical tones as different if you’re holding something that is vibrating faster or slower. If our vision system had a similar interplay, we might think that a person was heavier if we looked at them while holding a bowling ball, and lighter if we looked at them while holding a volleyball.
And your sense of touch can override your ears (not that they were that reliable to begin with…) when it comes to speech as well. Gick and Derrick (2013) have found that tactile information can override auditory input for speech sounds. You can be tricked into thinking that you heard a “peach” rather than “beach”, for example, if you’re played the word “beach” and a puff of air is blown over your skin just as you hear the “b” sound. This is because when an English speaker says “peach”, they aspirate the “p”, or say it with a little puff of air. That isn’t there when they say the “b” in “beach”, so you hear the wrong word.
Which is all very cool, but why might this be useful to us as language-users? Well, it suggests that we use a variety of cues when we’re listening to speech. Cues act as little road-signs that point us towards the right interpretation. By having access to a lots of different cues, we ensure that our perception is more robust. Even when we lose some cues–say, a bear is roaring in the distance and masking some of the auditory information–you can use the others to figure out that your friend is telling you that there’s a bear. In other words, even if some of the road-signs are removed, you can still get where you’re going. Language is about communication, after all, and it really shouldn’t be surprising that we use every means at our disposal to make sure that communication happens.