Everyone knows that eating begins with the eyes—but what do ears, those overlooked orifices, have to do with the process?
That's something that authors Ryan S. Elder of Brigham Young University and Gina S. Mohr of Colorado State University investigated in their recent study, "The crunch effect: food sound salience as a consumption monitoring cue," published in the journal Food Quality and Preference. The duo examined our perception of the sound that food makes as we eat, which is known as "food sound salience." Note that this is explicitly the sound coming from the food, and not the normal, intrinsic noises that are produced from chewing, slurping, swallowing, etc.: hence, "the crunch effect."
So, what's so special about foods that crunch, as opposed to just mushing around in your mouth?
"Crunchiness makes the most food sound," Mohr says, speaking to MUNCHIES. "You can take quiet foods, but then you confound the sound that your jaw naturally makes when you eat."
In the study, Mohr and Elder had groups of participants eat crunchy foods ranging from cookies to pita chips. In the first test, participants were asked to either chew loudly, chew softly, or were not given instructions. In cases where the participants paid attention to their food—either being asked to chew softly or loudly—there was a marked decrease in how much they actually ate. However, Mohr states, the results were still somewhat inconclusive because both situations made eaters more aware of the act of eating itself.
"With the first study, you could argue that people are just being more mindful," she says. "What we learned from that study [was that] both conditions in which people focused on the sound led to a decrease in eating, so we thought that maybe that wasn't the cleanest manipulation."
The next trial, which involved eaters using white-noise-producing headphones to diminish the sound of the food, proved more fruitful by modifying participants' hearing without directly forcing them to focus "without drawing additional attention to the eating process."
She says that the use of the headphones is analogous with many everyday behaviors of distracted eating, such as having the TV on during dinner or listening to music while you eat.
Basically, participants who were less aware of the sound of the food, due to higher levels of white noise, ate more than those that could hear the food they were eating.
"Similar to other ways that consumers can monitor how much they are eating, the sound that a food makes also creates these natural pause points," Mohr tells MUNCHIES, "so as long as you can hear the food you are eating, you are aware of the food's presence. When you are unaware, you sort of forget that you are consuming, which can lead to an increase in food consumption."
Mohr believes that in addition to learning more about how sound affects individual eating habits, there are also practical aspects of the study for food companies and consumers. "If we add more sound to food, is that advantageous for customers?" Mohr asks.
One food people should be aware of, though: Pop Rocks. Those carbonated candy crystals have a sound that is essential to the eating experience, and Mohr admits that food sound salience in that instance wouldn't lead to one eating less. So if you're snacking your way through half a tray of Rice Krispies treats on the couch watching It's Always Sunny In Philadelphia, be aware that the snaps, crackles, or pops could have a subliminal effect on your appetite.