unfortunately... but absolutely YES, they are calming, and I really like them.
Actually I don't have a 'sleep' app... but I do have a lot of those sounds of nature albums... I listen to them often.
The sound of 'water'... that seems to be universal, doesn't it? In that it's soothing to all? I've never heard of anyone who doesn't love the sound of water.. be it ocean waves, a babbling brook, whatever. I think it's primordial for humans. - JamesJM