One of the main sources of noise in restaurants and cafes is background music. It helps create a lively atmosphere, but sometimes sounds too loud.
Restaurant critic for The Washington Post, Tom Sietsema, notes that he has been paying close attention to this problem: “I've been talking about this for ten years. This is a source of constant irritation." In its reviews, Sietsma includes a noise level rating with decibel counts along with ratings of food quality.
But you also need background noise in the restaurant so that people don’t hear them slurping.