A few passages for the essence of the thing:
A mysterious hum has been keeping people in Hampshire awake all night ...
...
Male Midshipman fish let out a deep, resonating drone which attracts females and acts as a challenge to other males. ... once they get going can keep up the distracting hum all night.
... the noise created by the Midshipman is of such a low frequency and long wavelength that it can carry through the ground, walls ...
...
... "I thought I was going mad at first. ..."
The question then: what else might be disturbing our sleep we don't yet know about..?
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