WHAT YOUR STOMACH HEARS
Sound changes food’s taste, with high notes making it sweeter.
Intensifications that occur between sound and taste might be influenced by our personal memories
In Why You Eat What You Eat, Rachel Herz examines the science and psychology behind what we consume. Sometimes, what influences us is another sense, in this case, sound.
There is a famous Michelin three-star restaurant in Bray, England, called the Fat Duck. The Fat Duck is in aclass of restaurants that practise the art of molecular gastronomy. At the frontier of epicurean adventures, molecular gastronomy investigates the chemical and physical transformations of ingredients that occur in cooking, and exploits these physical manipulations along with artistic, technical and environmental strategies to startle diners’ expectations and senses while eating.
In addition to visual illusions and verbal ruses such as dishes called “sea scallop, coffee, cauliflower, orange,” sounds have been employed to augment the sensory experience of eating in molecular gastronomy restaurants. Indeed the Fat Duck is famous for introducing a dish called “Sound of the Sea” that is served along with an iPod hidden in a conch shell with trailing earbuds that one is instructed to insert while eating.
The iPod plays the sounds of waves lapping on a shore with a seagull squawking overhead, and the dish looks like a sandy beach where lichen and shells have washed up. Apart from the iPod garnish, everything in this elaborate concoction is edible and among its ingredients you will find: ground ice-cream cone, tapioca, seaweed, oysters, clams, sea urchin, miso oil and vermouth.
Although not all molecular gastronomy experiments are as pleasing or exciting as their chefs intend them to be, in the case of “Sound of the Sea,” which Heston Blumenthal, the celebrity chef and owner, introduced to his restaurant nearly two decades ago, the intellectual effort actually elevates the sensory experience into something profound when the iPod clicks into action.
Charles Spence, the acclaimed sensory psychologist at Oxford University who studies how our senses interact, has discovered that what we hear can directly affect our perception of what we are tasting. In a recent experiment, Spence and his students had people eat toffee, also made by the Fat Duck restaurant, comprised of sugar, butter, syrup, treacle (molasses with a slightly bitter bite) and a little salt while listening to one of two soundscapes.
One soundscape was composed of very low-pitched notes played by brass instruments, while the other soundscape was synthesized from high-pitched notes made mainly by a piano. While seated in a darkened booth — so that they couldn’t see clearly — the participants were given two identical pieces of toffee. The participants then put on their headphones and tasted one piece while the high-pitched melody played, and the other piece while the low-pitched melody played and rated how sweet and bitter they thought each piece of toffee tasted.
And even though the two pieces of toffee were identical, when people heard the high-pitched soundtrack they rated the toffee as sweeter and when they heard the low-pitched soundtrack they rated it as more bitter.
This isn’t just an abstract effect that happens in a psychology laboratory. Spence took his test to the streets and teamed up with the culinary artist Caroline Hobkinson during her month-in-residence at the experimental London restaurant, House of Wolf, and in October 2012, you could order the “sonic cake pop” for dessert — a nugget of chocolate covered bittersweet toffee that came with printed instructions to call a number on your cellphone.
When you called, an operator prompted you to “press 1for sweet or 2 for bitter.” If you hit 1, you heard a twinkling high-pitched melody and if you pressed 2 you heard deep sonorous tones.
Prior research in Spence’s laboratory has shown that people associate a low-pitch soundscape with bitter taste and a high-pitched soundscape with sweet. Spence calls these multi-sensory linkages “sensation transference,” a term borrowed from Louis Cheskin — a marketing innovator of the 20th century — who observed how consumers’ perception of a product was based on both the product and the sensory input associated with it. For example, the green colour of a 7UP can makes the soda taste more lemon-limey.
Our brain uses a cue from one sense, such as hearing or vision, to inform another sense, such as taste. Ben and Jerry’s, the legendary ice-cream emporium is apparently considering creating a set of sonic flavours with QR codes on their containers that you can scan with your cellphone to enable listening to flavour enhancing tones, while you dig into their ice cream. The sounds of “Chunky Monkey”?
But why do high-frequency notes make sweets taste sweeter and low-pitch notes make them seem more bitter? One explanation is that the perceptual change is based on the psychological associations and conceptual correspondences between our senses that we have learned through experience in the same way as it works for colours and shapes.
Desserts are typically round, so round shapes make food seem sweeter, and when we hear the jingling song of the ice-cream truck we know that a sweet treat is around the corner. Indeed, the fact that our eating history overlaps with our sensory perceptions is why “bacon and egg” ice cream — yes, for real — tastes more bacon-y when you hear bacon sizzling in the background while enjoying a cone, and the Fat Duck’s “Sound of the Sea” tastes “fresher” and more pleasing when diners eat it while listening to the lapping waves.
Another explanation for the tastesound connection we experience is that it is an example of the mild synesthesia that we all may possess. Synesthesia is the crossing over of one sensory experience into another sense. People with the full version of this condition vividly experience specific colours or sounds or tactile sensations when another sense is activated. In the case of “MW” — who was described in detail by Richard Cytowic in his book, The Man Who Tasted Shapes — chicken was “pointy.” The French composer Olivier Messiaen said that he saw colours when he heard certain musical chords and that these experiences informed his compositional process. Aside from these famous cases, we may all possess a mild degree of synesthesia such that high-frequency sounds trigger a vague sensation of sweetness and low frequencies a vague sensation of bitterness, which then tune our tastes accordingly.
It is also possible that the synergy between our senses is due to emotional associations. Low sounds tend to convey negative emotions and high frequencies are connoted as happy. As anyone who has listened to the musical symphony Peter and the Wolf will remember, the mean grandfather was the bassoon, while the innocent bird was the flute.
Since bitter is a bad taste and related to disgust, and sweet is a good taste and related to happiness, hearing low sounds may intensify the badness of bitter and high sounds enhance the trill of sweet.
The intensifications that occur between sound and taste might also be influenced by our personal memories. Some customers at the Fat Duck have been brought to tears while eating the “Sound of the Sea” because of the intense recollections that the aural and oral sensations evoked.
But the most intriguing explanation for why specific sounds change our perception of taste is that it is due to the correspondences between these sounds and the way our mouth moves when we experience certain tastes. The grimace we make when we taste something bitter is innate, and automatically instigates either expelling what we have in our mouth, or prevents anything else from getting in. In both the tongue-out or the pursed lips grimace, our tongue is pressed down in our mouth.
Now, if you were to try to make a noise with your tongue pressed down it would be a low-pitch sound (e.g., bleh). By contrast, when you are making the instinctive smiling face produced by having a sweet taste in your mouth your tongue presses against your upper palate, and when we make a noise with our tongue pressed against our upper palate it is high-pitched. In other words, there is an instinctive and biologically meaningful connection between making low-pitch sounds with our mouth and the real experience of bitter taste, and making highpitch sounds and sweet taste.
Most likely a combination of the inner wisdom in each of these theories explains why each of us at different times and in different situations experiences a synergy between the sounds we hear and the tastes we’re tasting. Besides altering the taste of toffee, or how fresh and delicious a seafood concoction seems, what we hear can, among other things, influence the wine we’ll buy, how much we’ll spend at dinner, how much and how fast we eat, how crispy, sweet, salty or umami-ish foods seem, as well as how much we enjoy what we are eating. Excerpted from Why You Eat What You Eat by Rachel Herz. Copyright © 2018 by RSH Enterprises, LLC. Used with permission of the publisher, W.W. Norton & Company, Inc. All rights reserved