Biologists at the University of Washington's Marine Biology program believe the source of the noise may be the male midshipman fish, which can be found in a local waterway.
The midshipman fish lets out a distinctive mating call that sounds like a drone and can go on for hours as males compete against each other for female attention. Researchers believe the mating calls may be bouncing off ships and buildings, amplifying the sound.
But scientists attempting to record the strange hum on Friday were unable to pinpoint the source of the noise.
Typical Midshipman Type II male calls are divided into: short grunts that last for milliseconds or are produced in a series of grunts called a “grunt train,” mid-duration growls, and long duration advertisement hums that can last up to an hour.
These calls can be recorded naturally. They can also be produced in a laboratory, a procedure known as “fictive calling” In nature, two muscles contracting on the swim bladder produce these sounds. In the lab, sounds are produced by a stimulating electrode placed on the periaqueductal gray (PAG) and a recording electrode placed on the occipital nerve that leads to the sonic muscles of the fish.Wikipedia....
Steroid-Mediation The vocalizations of male midshipman fish are androgen and estradiol steroid mediated. There are high blood levels of these hormones during the transition from non-calling to calling before midshipman breeding season, suggesting that higher hormone levels are needed for making advertisement calls. Feeding 11-ketotestosterone coated scallops to toadfish increases their calling behavior, which identifies 11-ketotestosterone, an androgen hormone, as a mediator of midshipman fish vocalization.
Originally posted by Unity_99
Its NOT fish.
I listened to a recording of it, and it is quite techno sounding, not plates, not fish, and I suspect HAARP.
It also is identical, or nearly, to what we heard over a year ago spring of 2011. For over a week. That was both inside and outside, off and on. We're over an hour from the coast.