Re: But neither story answers the important question
Unfortunately, this noise is not restricted to Southampton.
I live in Weston-super-mare and I have been hearing this type of low hum/pulsating for weeks now, so unless these fish are dashing around the Cornish headland and massing just off the sea front to serenade me to sleep, i believe we may be have a wider problem.
It could also be that these type of fish are grouping in large numbers, placed strategically around the British coastline, ready to give a national rendition of 'Jerusalem' when England win the 2014 world cup!
But maybe not......