I once took a bite of fruit that made the crispest sound like a fresh apple. It was a loud crunch. The memory would’ve been good had I actually been eating an apple. But no, it was a banana. Want to hear the rest of the story? Read on!
July 19, 2017
While I don’t exactly remember the flavor of this banana (honestly, it was pretty flavorless), the icky sound from 13 years ago stayed firmly in my mind. It was then and there that I realized how sound could affect the way we taste just as much as flavor or look.
This concept is certainly familiar to Charles Spence, a gastro physicist, and Professor of Experimental Psychology who has spent the past 20 years researching on the influence of our four other senses on our assessment of taste at the University of Oxford.
In 2008, Spence and Max Zampini published their Ig Nobel prize-winning study on “sonic chip,” involving 20 volunteers judging the freshness of 180 Pringles (that’s about two tubes) while manipulating the crunching sounds that people heard over headphones. As it turns out, making the crunch louder resulted in people perceiving the chip to be around 15% crunchier and fresher than if quieter sounds are played back instead.
However, as demonstrated by my crispy banana story, louder crunchier sounds don’t necessarily make all food taste better. Spence noted:
Aside from the withdrawn Sun Chips packaging by Frito Lay due to its excessive noise back in 2010, one of the biggest problems at the moment lies in those incredibly noisy restaurants in the States (especially in NYC). With certain background noise or music levels exceeding 100dB, diners are effectively hampered in their ability to taste and enjoy the food.
But first and foremost, how do sounds even affect our taste at all?
To answer this question, Spence shares an excerpt from his latest book Gastrophysics: The New Science of Eating, published by Viking on June 20.
The sound of food
Many of the food properties that we all find highly desirable—think crispy, crackly, crunchy, carbonated, and, of course, squeaky (like halloumi cheese)—depend, at least in part, on what we hear. Most of us are convinced subjectively that we “feel” the crunch of the crisp. However, this is simply not the case. Introspection, after all, often leads us astray and, based on the results of the gastro physics research, I can assure you nowhere is this truer than in the world of flavor. (Take, for instance, the experience of carbonation. Most people, if you ask them, will swear blind that they enjoy the “feel” of the bubbles bursting or exploding in their mouths. It turns out, though, that the sensation is mediated primarily by the sour receptors on the tongue; i.e., by the sense of taste, not by the sense of touch at all.)
Given that we don’t have touch receptors on our teeth, any feeling we get as we bite into or chew (masticate) food is mainly mediated by what is felt by the sensors located in the jaw and the rest of the mouth. The latter, removed as they are from the action, do not provide any unusually precise information about the texture of food. By contrast, the sounds that we hear when a food fractures or is crushed between our teeth provide a much more accurate sense of what is going on in our mouths. So it makes sense that we have come to rely on this rich array of auditory cues whenever we evaluate the textural properties of food.
Some of these sounds are conducted via the jawbones to the inner ear, while others are transmitted through the air. Our brains integrate all of these sounds with what we feel, and in the case of the sonic chip, this happens both immediately and automatically. And so if you change the sound, the perceived alteration in food texture that follows is experienced as originating from the mouth itself, not as a funny sound coming from your ears. This means that most of us are oblivious to just how important the sound of the crunch is to our overall enjoyment of food! And this isn’t just about the crunch: the same goes for crispy, crackly, creamy and carbonated, though the relative importance of sonic cues to our perception of texture and mouth feel probably varies for each particular attribute. My suspicion is that what we hear is likely to be more relevant, and hence influential, in the case of crackly, crunchy and crispy foods than in the event of carbonation and creaminess perception. Nevertheless, research points to the conclusion that what we hear plays at least some role in delivering all of these desirable mouth sensations, and more.
By Eustacia Huen
To read Eustacia Huen’s full story visit Forbes.com