I think it's part of the charm. That dun dun dun DUH noise the trains make as they're pulling out of the station is a sound as quintessential to New York as any I can think of. Oh and if you think it's loud, you should have taken it 15 years ago when they still ran the older R33 "Redbirds" and more of the R32 style subway cars. Now THOSE were loud!