Hip and trendy restaurants encourage buzz. Loud conversation and music are considered mood enhancers, and young customers, especially, equate din with good times. Sometimes that is exactly what you want. But when the buzz becomes a roar and you have to yell at your table mates, then there's a problem. Think about your last restaurant experience. Did you have to raise your voice to carry on a conversation? Did background noise make you repeat and repeat what you said? Will you ever go back?a brief history essential to the subject.