Ive got a load of files you can have. They are just ones I've collected off various swift sites.
Notes:
When you say "bluetooth" , I assume you are playing them from your phone to a bluetooth speaker? The danger of this is that your phone speaker will play other sounds too unless you put your phone on Do Not Disturb while you play them!
You can loop a set of files with Spotify, join them together or repeat them with Audacity, or play them in an automatic loop off a usb stick with a cheap amp. I use cheap amps with a wifi timer, so it's hands off, and I can easily turn it off for the day if the weather is bad.
You can use a silent mp3 to create a gap, by copying it as many times, and in whatever order you fancy.
Ron