Noisy restaurants are a source of perennial complaints, but it’s not just diners’ ears that are affected — it’s their waistlines, too. A new study published in the Journal of the Academy of Marketing Science has found that if ambient music played in a restaurant is louder, the customers are more susceptible to choose unhealthful foods. Dipayan Biswas, a marketing professor at the University of South Florida, conducted the study at a cafe in Stockholm, where various genres of music were played on a loop at 55 decibels and 70 decibels at different times, for several days. When the music was louder, researchers found 20 percent more customers ordered something that was not good for them, compared to those who dined during the lower-volume times. Softer music is calming, and louder music gets us amped up. “Volume is proven to directly impact heart rate and arousal,” according to the study. And it affects our decision-making, as well: In the soothing quiet of some gentle jazz, we have better self-control, and we make better decisions about which foods would be better for us. But in the excitement of loud rock music, we want meat and cheese on a bun, dammit, and some french fries on the side. Oh, and a beer . . . or three. Though the study is new, it reinforces conventional wisdom that restaurant owners have known for quite some time: Creating the right atmosphere is essential. Music “creates a vibe. Your body starts tingling,” said Alex McCoy, the chef-owner of Lucky Buns, a burger restaurant in Washington. “The more essential you make the experience, the more your brain just starts going crazy. You want to buy things, you want to eat, you want to meet people.” McCoy’s internationally inspired burgers and fried chicken sandwiches have been lauded as some of the best in the District, and his restaurant is, according to Yelp reviewers, “wicked loud,” “but worth it!” He typically plays loud Euro house music or reggae, letting the thumping beat pulse through the restaurant, “a playlist that allows [guests] to get lost in the music.” “Different songs, mixtures, genres of music, it creates this chaotic setting,” he said. “And to me, those create the best bar vibe, when a song comes on and [diners are] like, ‘Oh yes! That’s the song! Get a round of drinks.’” McCoy says he has never compared his sales during periods of different volumes of music. But there are four side salads on the menu, and any burger or fried chicken sandwich can be served on a bed of lettuce with no bun. You will not be surprised to learn that these options have not been top-sellers, especially compared with the burgers served with bacon jam and Gouda, or the fried chicken with pickles and Sriracha. Restaurants weren’t always this loud. New York Magazine food writer Adam Platt pinned the origin of the “great noise boom” to the late ’90s, when now-disgraced Mario Batali’s restaurant Babbo was known for blasting Led Zeppelin, the Who and the Pixies. (The chef is now facing a criminal investigation after he has been accused of sexual assault.) Chefs such as David Chang began to ascend to the status of rock stars, and they pumped up the volume in their restaurants, all in an effort to draw in younger people who liked the raucous vibe. But loud restaurants can be a deterrent for older guests or the hard of hearing, or people who just want to enjoy dinner conversation without shouting till they are hoarse. And, in some cases, restaurant volumes can be an occupational hazard for the people who work there. Consistent exposure to noise levels above 70 decibels can cause hearing loss over time. In Platt’s story, he found some restaurants reached decibel levels in the 90s, louder than a lawn mower. The volume at a downtown Washington Shake Shack around 12:30 p.m. — the height of the lunch rush — was 75 decibels including both music and ambient noise, the equivalent of hearing a “freeway at 50 feet from pavement edge,” according to one chart of comparable sounds. A nearby Sweetgreen — a salad chain that used to throw a music festival — came in at 80 decibels, the equivalent of a garbage disposal. But Biswas’s paper shows that noise can sway diners to order certain types of foods, potentially increasing the value of their check. “Restaurants and supermarkets can use ambient music strategically to influence consumer buying behavior,” said Biswas in Science Daily. According to the study, “These findings allow restaurant managers to strategically manipulate music volume to influence sales.” So when you hear Cardi B blasting in your local lunch spot, she’s not the only one making money move. And she might be the reason you’re inexplicably craving fries. The Washington Post