Thank you so much to everyone who got in touch with offers of sound files for us to use in our visitor centre. We had responses from lots of places and have a nice collection of files now, so thank you to such a helpful community!

I thought I would share some of the public websites that were mentioned for reference.

William Watkins marine mammal sound database
https://cis.whoi.edu/science/B/whalesounds/index.cfm

Sea of Sound,  Cornell
http://www.birds.cornell.edu/page.aspx?pid=2230#

NOAA SWFSC
https://swfsc.noaa.gov/textblock.aspx?Division=PRD&ParentMenuId=148&id=5776

NOAA NEFSC
https://www.nefsc.noaa.gov/psb/acoustics/sounds.html

Thanks again, 
Bryony and Jen, 
Manx Whale and Dolphin Watch