Is there a way to quieten the annoying HUM of ventilation equipment?

Question

I live on the top floor of a building surrounded by large residential roof top ventilation units. Now that summer is here they're on all the time and driving me crazy! The Department of Environmental Protection is of very little help.

Answer 1

Hello Scott:

There isn't much you can do about the machines. Have you tried the Bose noise-canceling head phones? They record outside noise, and invert the signal so the sound waves cancel each other.