Our Perception of Taste: What’s Sound Got to Do with It?

music

My first love as a speech-language pathologist is pediatric feeding.  I spend lots of time talking to little kids about “carrot crunchies” and “pea-pops” and various silly names for the sounds that different foods make in our mouths as we explore all of the sensory components of food in weekly treatment sessions.

Is it possible that sound is a larger component of our eating experience than many of us realize? What’s sound got to do with eating, or more specifically, with taste? Discovering how the sound of a crunching potato chip affects flavor is more than just curiosity.  Prof. Charles Spence, who leads Oxford’s Crossmodal Research Laboratory, studied how the sound that food makes in our mouths influences our perception of freshness.  It’s an important point for potato chip manufacturers, who strive to create the “crunchiest crisp possible.”

Background sounds in the environment also influence our interpretation of taste.  Spence conducted an experiment where individuals were presented with 4 pieces of identical toffee.  Two pieces were eaten while the subjects listened to the lower pitch of brass instruments.  Two other pieces were eaten while listening to the higher pitch of a piano.  The pieces eaten during the higher pitched piano music were rated “sweet” by the subjects and the pieces eaten during the lower pitched music were rated “bitter.”

Chef Blumenthal, owner of The Fat Duck near London, has taken Spence’s research findings to the next level.  Order the “Sound of the Sea” and you’ll enjoy more than seafood delicacies  presented on “a sand of tapioca and fried panko, then topped with seafood foam.” The dish is accompanied by an iPod nestled in a seashell, “so that diners can listen to the sound of crashing waves as they eat.” Spence reports that diners experience stronger, saltier flavors with the sound of the ocean in the background.  Another London restaurant, the House of Wolf, serves a cake pop along with instructions to dial a phone number and then, before tasting,  press 1 for sweet and 2 for bitter.  Diners who listened to the first prompt heard a high pitched melody and those who pressed “two” heard a low brassy tones.   In an article for the Telegraph, Spence said,  “We have also looked at the crispiness of crisps and biscuits and found that by boosting certain high frequency sounds when volunteers bit into them we could make them taste crunchier, and they became softer if we dampened those frequencies.”  It’s not just diners across the pond who are experiencing the marriage of sound and taste. Major food companies in the United States also have consulted with Spence, who developed a soundtrack to “complement”  the coffee at Starbucks®.  Speaking of coffee, in a recent study, Spence found that humans can detect whether a liquid is hot or cold, just from listening to the sound of it being poured into a glass, porcelain, paper and/or plastic cup.  I’ll consider this the next time I’m waiting for my drink at the local coffee shop.  Perhaps, from now on,  I can just listen to the sound of the pour, grab my drink and avoid the barista announcing “Lite Iced Triple Venti Half-Pump Americano Skinny for High Maintenance Melanie” with that smirk on his face.  But, I digress…

When I consider my little clients in feeding therapy, I wonder how this research might be expanded to detect possible differences in taste perception in children with sensory processing challenges, including kids with autism. Certainly, respecting the differences in a child’s sensory system is an integral part of feeding therapy for most clinicians.  Could it be that this hiccup in auditory, visual, gustatory or other sensory systems communicating efficiently with one another makes eating a variety of foods especially difficult for some children, more than we know at this time?  A recent article in The Journal of Neuroscience reported that kids with “autism spectrum disorders (ASD) have trouble integrating simultaneous information from their eyes and their ears” and discussed how this might affect their language skills. Wendy Chung, MD, PhD at Columbia University Medical Center explained in a recent video for parents how a poorly functioning pathway for simultaneous auditory and visual information (and the secondary problems of processing and responding to sensory signals) causes a child with ASD to be overwhelmed in environments that we find quite comfortable.  Perhaps future research may include Spence’s work and how it might apply to children in feeding therapy. Would certain tones be more soothing while eating?  Would certain music in the school cafeteria help children eat faster or even choose more nutritious foods? The common phrase “a feast for the eyes” may one day turn out to be “a feast for the eyes and ears” as we consider all the possibilities.

Melanie Potock, MA, CCC-SLP, treats children birth to teens who have difficulty eating.  She is the author of Happy Mealtimes with Happy Kids and the producer of the award-winning kids’ CD Dancing in the Kitchen: Songs that Celebrate the Joy of Food!  Melanie’s two-day course on pediatric feeding is  offered for ASHA CEUs and includes both her book and CD for each attendee.  She can be reached at Melanie@mymunchbug.com.