"This is must be a somewhat American problem. I once was at a Cheescake factory there, where it was so loud we could hardly talk with each other. We hypothesized that they do this for a higher turnover."
I've heard that the loudness in restaurants isn't meant to increase turnover - it's actually used to attract people to the restaurant. The average restaurant-goer in NYC seems to have an aversion to places that are quiet enough to carry on a normal conversation. They apparently find the noisy environment to be stimulating and exciting. There are even special sound systems designed for restaurants that amplify certain components of the ambient noise if the natural acoustics of the room aren't noisy enough.