I guess restaurants were noisy in Will's day too! We ate at a restaurant in Temecula on Friday where the noise was incredible - music from the bar, people talking, dishes clattering, cell phones ringing, kids crying. We couldn't talk, couldn't think and certainly couldn't enjoy our food.
Once a restaurant starts to get noisy, the noise itself begets more noise. Everybody starts to speak louder. The waiters were yelling at each other and at us. With my hearing disability which combines deafness and acuity, I was toast. We hesitated when we walked through the door and usually we turn around and leave if the noise level is high. But we were hungry and the restaurant was convenient and so we suffered.
When I worked on restaurant concepts noise was frequently a design factor. Johnny Rockets with their juke box and singing servers cultivated the noise to create the ambience they were shooting for. It can be an important component of a vibrant and exciting atmosphere. Noise means action and energy but in my opinion it has a negative effect on flavor. All sensory experience is enhanced by concentration and noise is distracting to say the least.
Some level of masking music is perfectly acceptable to me as long as I'm not under a speaker. "Background music" should be just exactly that - in the background and an enhancement to comfort and conversation - not the main event.
Drink a glass of wine standing at a crowded noisy bar; then drink the same glass of wine in a quiet environment with all of your focus and they are two entirely different experiences.