Research in China and Denmark has revealed that, across cultures, certain types of music can cause people to spend more time fixating on healthy foods than on unhealthy alternatives, suggesting that healthy eating habits could be promoted through the use of sound.

The new study, published April 16 in Appetite, is one of the first to consider how music alters food choices in both Eastern and Western cultures. It involved a total of 215 participants from China and Denmark. In general, food preferences were consistent in both sets of participants. The "healthy" and "unhealthy" soundtracks were constructed based on the results of a pre-study that asked participants from both nations to identify associations between various foods and tonal qualities. Those outcomes were largely consistent across both cultures, despite some differences in the associations between healthiness and music genres. Chinese volunteers tended to associate rock and classical music with unhealthy eating, while Danish participants found that hip-hop music conjured the essence of unhealthy eating. 

Those who listened to a "healthy" soundtrack spent more time fixating on images of healthier foods, such as vegetable sticks, tuna salad and pineapple. They spent less time focusing on images of less healthy foods such as mini-doughnuts, pizza and potato chips, establishing what the paper described as a "causal relationship between healthy sounds and healthy food choice." Chinese and Danish participants were presented with identical food choices throughout the study.

"Usually, when we think about food, we think about the taste and the aroma and, of course, the sight of it," Danni Peng-Li, a doctoral student in the department of food science at Aarhus University and the study's lead author, told The Academic Times. "But sound has been, I would say, underrated" as a topic of research, he added.

It can be difficult to track humans' food preferences, because they are not always based on rational decision-making. Instead, those choices are governed by both physiological, hunger-based needs and subconscious or emotional desires, Peng-Li said. Additionally, the definition of "healthy" food is somewhat subjective — influenced by a person's cultural food traditions.

A previous study conducted by the team showed that humans implicitly and explicitly associate certain sounds with basic tastes, such as bitterness and sweetness. But the present study proves that those "sonic seasoning effects" — explored in earlier investigations that have also considered the intersections of food and sound — also carry over to more abstract concepts, such as healthiness, which can vary across cultures.

In accordance with the findings from their pre-study, the researchers created a "healthy" version and an "unhealthy" version of a song. Both versions consisted of roughly the same melody but differed in characteristics such as instrumentation and tempo. The "unhealthy" song was rock-oriented: It featured harsh, distorted guitars, a fast tempo, cymbal-heavy drums and minor notes. The "healthy" song, on the other hand, sounded jazz-like, with piano, a slower tempo and a major mode.

The scientists also augmented the background noise in each song to widen participants' preferences for healthy or unhealthy food options. The "unhealthy" soundtrack was underlaid with the sounds of a bustling cityscape, complete with car horns and traffic. Researchers hypothesized that those grating, stress-inducing sounds would compromise volunteers' higher-level brain functions, giving them less of an opportunity to think through their choices. Meanwhile, the "healthy" soundtrack included a peaceful backdrop consisting of ocean waves and seagulls, which has been associated with healthiness in previous research.

Overall, both Danish and Chinese participants chose healthier foods when the "healthy" soundtrack was being played, determined by the extent of fixation each participant had toward a healthy food choice as well as the number of times they revisited that particular choice. These preferences were tracked by monitoring participants' eye movements. The researchers theorized that the "healthier" soundtrack might have been easier to listen to, or at least less distracting, giving participants an opportunity to think through their decisions more deliberately. 

For Peng-Li, there's a clear way to implement these findings in real-world contexts: Marketers, governments and chefs can choose music that has basic tonal qualities found to encourage healthy eating while avoiding harsh tones and fast tempos that are thought to drive people to make more unhealthy food choices.

"It's not that you have to spend many months to conduct a study and find the accurate musical parameters that are associated with something specific," Peng-Li said. "It's just a suggestion for people who want to apply this to be more reflective of the choice of sound and music" they use in their eating establishments or retail settings.

This research builds on significant prior research that has investigated how soundtracks influence consumption. In groundbreaking work from the late 1990s, researchers found that, over a two-week period, supermarket shoppers were more likely to purchase German wine when German music was playing in the background. When French music was playing, on the other hand, French wine became customers' preference. In the vast majority of cases, purchasers said that music was not a factor in their decision, suggesting that the influence of sound on behavior is somewhat subconscious. Those researchers posited that German music prompted memories and thoughts associated with Germany, which made consumers more inclined to purchase German wine. The same was true in the case of French music.

Today, private companies are experimenting with using sound to augment the taste of food, hosting multisensory dining events that ask participants to listen to different sounds while enjoying a meal. Studies have indicated that loud or distracting music can impair or enhance our ability to detect certain flavors, like sweet and sour, depending on the context. "Some restaurants — especially Michelin restaurants — are already playing around with these ideas. They are perhaps more progressive in this [regard]," Peng-Li said. "But I think you can apply it not only in the domain of food and retail, but in all formats."

The study "Sounds healthy: Modelling sound-evoked consumer food choice through visual attention," published April 16 in Appetite, was authored by Danni Peng-Li, Derek V. Byrne and Qian Janice Wang, Aarhus University and University of Chinese Academy of Sciences; Signe L. Mathiesen, Aarhus University; and Raymond C.K. Chan, Institute of Psychology, Chinese Academy of Sciences, and University of Chinese Academy of Sciences.

This article has been updated to clarify the definitions of "healthy" and "unhealthy" sounds.