On weekdays, when the clock strikes noon and the weather cooperates, downtown sidewalks clog with hurried office workers, many of them headed for the food trucks that surround Farragut Square and Franklin Park, along the K Street corridor.

But long before prospective customers catch a whiff of the Puerto Rican plantain-based mofongo, or lobster with tarragon mayonnaise, they are enticed — some might say bombarded — with sounds as diverse as the fare: brass-and-conga-rich salsa, 1980s pop-rock, rap, reggae and the unmistakable rhythms of go-go.

A far cry from the Mister Softee jingle, the one that still sends the inner child in all of us bolting out the door. Or maybe not so far. Many food-truck proprietors believe — along with their brick-and-mortar counterparts — that music is an essential companion to food. (And, less poetically, that it can help establish their brands in a competitive marketplace.)

Research by David Melcher, a professor of cognitive sciences at the University of Trento in food-savvy Italy, bolsters this notion. “The association of sounds and food starts very early, perhaps even prior to birth,” Melcher says. “Hearing the sound of the ice cream truck may be similar to Pavlov’s dog hearing the bell associated with mealtime. It readies our entire body for the fact that we are about to eat a particular food.”

And some Washington food trucks seem to be laying bets that a particular food requires particular music. “Everything we do is authentic Puerto Rican dishes, so we try to stick to a theme from the island,” said Enrique Velazquez, chef, president and co-owner of Borinquen Lunch Box. A favorite side dish to his asopao de pollo (chicken gumbo): salsa music from Puerto Rican dynamo Marc Anthony, ex-husband of Jennifer Lopez and perhaps a bigger star on the island than the “American Idol” judge.

At ChefDrivenDC — “Champagne Taste on a Sasparilla Budget” — owner Jerry Trice of Fredericksburg, Va., uses local products in such dishes as risotto asparagus croquettes and Thai pork sliders. His music of choice: “definitely local.” “We rock a lot of Chuck Brown, Rare Essence, go-go, you name it. A lot of Eighteenth Street Lounge stuff,” Trice said. “We’re a local, sustainable product. I implement that as far as the truck and the concept of the truck.”

Of course, the music and the cuisine don’t always match. One afternoon at Red Hook Lobster Pound, which sells lobster-roll meals ($18, with Cape Cod chips and a drink), Cyndi Lauper’s “Girls Just Wanna Have Fun” segued to Sting’s “Every Breath You Take.” Co-owner Leland Morris insists, though, that his musical education didn’t stop at 1983. “We like to mix it up.” At the House of Falafel, owner Naceur Negra sells chicken and beef shawarma to a house techno beat. And on a recent afternoon, Bob Marley streamed from the Fojol Bros. truck, where the menu includes chicken masala and shiro with beef.

At Kraving Kabob, whose Web site describes its food as “a concoction of authentic home made american, mediterranean and middle eastern cuisine,” Hot 99.5 blasts from the speakers. Lively music to inspire a lively appetite? Some customers must think so.

Others disagree. Farbod Kadkhoda, a 24-year-old recent transplant from Los Angeles, offers a one-word description of the soundtracked food-truck phenomenon: “Annoying.”

Sometimes the food truck operators take sentiments such as Kadkhoda’s into account and self-regulate. Trice, of ChefDrivenDC, said he recalls a couple of days this spring when the only sounds emanating from his truck were the hum of generators and the sizzle from the cooktop. Another truck “was rocking a lot of Beastie Boys when Adam Yauch died,” Trice said, referring to the musician who succumbed to cancer in early May. “And they had a better system than we do, so we turned ours off.”

And for all the effort some proprietors put into selecting the right tunes, most say that music doesn’t really affect the bottom line. But don’t expect Gauri Sarin, co-owner of Something Stuffed (empanadas filled with local, grass-fed beef and pork) to turn off the music. “We definitely do it for ourselves, too,” Sarin said.

“We can hear the music in the truck, and that just keeps our atmosphere up and our employees lively.”

What’s your lunchtime playlist? Listen to reporter Clinton Yates’ picks, and tell us what you’d nosh to on the Style Blog.