One Steven Gray of Pacific Grove blames the noise on military research. Nope Steven just fish looking for love.

The sound is being heard by residents living about a quarter-mile away from the Monterey Bay Aquarium. Jim Covel, the aquarium’s director of guest experience — who has experience with this species — said the sound likely comes from “lonesome males” trying to attract mates.
The endless motor-like sounds are produced by their strong muscles pressing against their balloon-like bladders. They hit the bladder about 6,000 times a minute — twice the speed of a hummingbird’s wings — and do it during a mating season that usually starts in May and ends in September. The loud hum can last for more than an hour at a time.