But [music designer Wyatt] Magnum said the Hard Rock Cafe had the practice down to a science, ever since its founders realized that by playing loud, fast music, patrons talked less, consumed more and left quickly, a technique documented in the International Directory of Company Histories. While not denying this tactic, Hard Rock said its current approach was “vastly different,” with on-site video and guests helping to select the music.
There is research supporting Mr. Magnum’s theory. In 1985, a study by Fairfield University in Connecticut reported that people ate faster when background music was sped up, from 3.83 to 4.4 bites per minute. Nicolas Gueguen, a professor of behavioral sciences at the Université de Bretagne-Sud in France, reported in the October 2008 edition of the journal Alcoholism: Clinical and Experimental Research that higher volumes led beer drinkers in a bar to imbibe more. When the bar’s music was 72 decibels, people ordered an average of 2.6 drinks and took 14.5 minutes to finish one. But when the volume was turned up to 88 decibels, customers ordered an average of 3.4 drinks and took 11.5 minutes to finish each one.
--Cara Buckley, NYT, on acoustic profit maximization