Seattle residents have been plagued with a mysterious hum, audible in parts of the town for the past few days.
At first, irritated locals blamed heavy industry – but businesses denied being responsible for the throbbing noise.
Now scientists have come up with an unusual explanation for the persistent buzz – they say it could be the sound of fish looking for a mate.
The so-called ‘West Seattle hum’ has apparently been heard periodically over the years, but since the Labor Day weekend it has been more persistent.
Local resident Julie Schickling told KING 5 she noticed the bizarre sound one night last week, and went out to record it.
‘It gets high and lower, and goes away, then comes back,’ she told the station.
Popular theories for the origins of the noise included a nearby cement factory and tanker ships operating off the coast.
But marine biologists at the University of Washington have suggested that the culprit could in face be the Midshipman fish, believed to live in the nearby Duwamish waterway.
The male fish let out a distinctive drone to let females know they are searching for a mate.
The noise can go on for hours and increase in volume as males compete against each other for female attention.
And scientists say that the sound could have been amplified by bouncing off buildings and ships.
However, when two researchers took recording equipment out on Thursday night, they were unable to reach a definitive answer on the source of the noise.
Mechanized mystery hums have sounded out in random parts of the US over the last year and a half.
Information obtained by theintelhub.com shows that possibly, the sounds are derived from advanced tunneling technology.
However this news piece shills out, blaming the sounds on fish.