The Weird Connections Between Hearing and Taste

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Sound guides us every moment of every day. In many interactions, we gather troves of sonic input about people or things long before we form opinions about appearances. We get information from sounds, even the smallest ones, and that information is combined with the emotions those sounds make us feel, or the past experiences they make us recall.

But what’s surprising is that sound, in addition to its power to elicit all sorts of memories and emotions, can actually affect our perceptions of flavor. Unilever is the Anglo-Dutch multinational corporation that owns four hundred brands, including such beloved names as Dove, Lipton, PG Tips, and Ben and Jerry’s. In 2012, it partnered with the University of Manchester in England to study the effect of noise on taste. The study found that people enjoyed their food more when they also enjoyed the background music playing. Loud white noise played at eighty decibels (about as loud as a blender or a washing machine), however, dulled the perception of flavor. When it’s there, people perceive salt or sugar less intensely. What’s even more interesting is that when that same background noise is going, people perceive more crunchiness. The study offers all kinds of insights about matching sounds and culinary objectives. Use white noise when you want to play up crunchiness, for example, and make sure you bring the beats and melodies if you want diners to appreciate subtle or complex flavors. Sound, in other words, is a vital yet often overlooked ingredient in meals.

There’s a real-life situation where you’ve probably experienced this. How do you feel about airline food? It’s pretty bland, right? While the low humidity in an airplane cabin and the cabin pressure affects the way you perceive taste, the Unilever study suggests that the lack of flavor in onboard meals can be partially blamed on the dull drone of the airplane engines. That type of noise makes you less sensitive to salt, sugar, and spices. But you do notice more crunchiness, according to the study, which would help explain why you’re likely to pass on the in-flight Salisbury steak but ask for a second bag of peanuts.

When it comes to the study of crunchiness, no one is more renowned than Charles Spence, who heads up the Crossmodal Research Laboratory at the University of Oxford. In 2004, Spence and fellow experimental psychologist Massimiliano Zampini published a now-famous study called “The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Chips” in the Journal of Sensory Studies. The researchers used Pringles chips because they are close to perfectly uniform — both within the chip and from chip to chip. They’re molded from an alarmingly pliable kind of potato paste. Participants in the study sat in a soundproof booth wearing headphones and were positioned in front of a microphone as they bit into the Pringles chips. The sound of the crunch that came from the chip was routed through the microphone and then fed back through the headphones. Some of the crunch sounds were manipulated — made louder or tweaked on certain frequencies so the participants heard a kind of megacrunch in their headphones.

Participants operated foot pedals that controlled a computer-based visual analog scale, which they used to rate the crispness and freshness of the chips they crunched into and heard. Spence and Zampini found that “the potato chips were perceived as being both crisper and fresher when either the overall sound level was increased or when the high-frequency sounds (in the range of two to twenty kilohertz) were selectively amplified.” In other words, the louder or sharper the crunch, the fresher the chip seemed. Crispness and freshness is actually in the ear of the beholder.

Since his crunchiness study, Spence has kept at it. In a demonstration that was probably more fun than scientific, he paired up with Heston Blumenthal, the chef at the Fat Duck in England, one of the world’s highest-rated restaurants. Together they concocted an experiment meant to measure the way sound influences the perception of taste. It involved Blumenthal’s bacon-and-egg ice cream. (He serves it with fried bread — the crunchiness is meant to trigger the experience of crunchy bacon.) At a conference on art and the senses, Spence and Blumenthal had participants taste the ice cream dish and rate its “egginess” and “bacony-ness” while they listened to one of two different sounds. One sound was bacon sizzling, and when it played, people rated the bacon flavor higher than the egg flavor; the other sound was chickens clucking, and when that one was played, participants rated the egg flavor higher. Even though the participants must have known they were being manipulated by sound, they couldn’t help themselves.

Supermarkets are a prime example of sound’s potential to whet our taste buds, particularly in chains like like Publix in Florida. If you’ve found yourself there — or at a select Safeway, Piggly Wiggly, or Kroger — you might have encountered a fantastic potential use of sound, albeit one that’s unrealized. You’ll hear it in the produce aisle: a curious rumble coming from the direction of the spinach and cilantro. At Publix, “Where Shopping Is a Pleasure” (you can probably sing the slogan if you grew up in Publix country), the rumble is followed by a sudden crack and a boom. Then comes the sound of rain. You turn your head and see what looks like a storm raining down on the carrots and Bibb lettuce. There’s a rain forest right there in aisle one!

You might have zero idea whether this does anything positive for the food as it sits on a shelf. But it sounds fresh. And this isn’t some random stockperson blasting your salad with a garden hose. This is nature. I mean, it’s not really nature. But it sounds like nature. And you can’t help but think about those carrots and that lettuce, now miles from any farm, still thriving, soaking up a cool drink from the clouds above.

Excerpted from “Sonic Landscapes” from The Sonic Boom: How Sound Transforms the Way We Think, Feel, and Buy by Joel Beckerman with Tyler Gray. Copyright © 2014 by Man Made Music, Inc. Reprinted by permission of Houghton Mifflin Harcourt. All rights reserved.

The Weird Connections Between Hearing and Taste