Whatever you do, DO NOT buy one of those bedside sleep sound recorders. There's just too much iffy shit you hear on those, if you listen closely and you hear stuff you can't ever forget. I tried it once. The one I had would skip to the places where there was noise.

I heard my snore stop suddenly, like my breath stopped or a hand over my mouth silenced me, and then I hear a clear whisper "Don't wake up!"

I don't know if it was me talking or what, but I'd rather not know the noises in my room at night! Never again for me.