Welcome to Reef2Reef!
Interesting question! If the sound in the air is strong enough to cause vibration into the tank water, it could startle the fish (not corals though). However, fish soon become accustomed to vibration. The story I always give was a German public aquarium that had a strong policy against any tapping on the tank glass by the visitors. Makes sense, EXCEPT that it then kept the tank tapping to a minimum, but didn't eliminate it entirely. Once in awhile, somebody would still tap and the fish would be startled and would dart around. At the aquarium I managed, we didn't really police this activity, and the fish soon learned to ignore the frequent tapping and were fine. The same sort of thing seems to apply to flash photography.
There was a study done on seahorses many years ago that discovered that the hum and vibration of pumps and filters DID cause chronic stress in seahorses.
Jay