This is some room tone I recorded in a thankfully quiet time in my studio. It's an Oktava 012 microphone ...
High frequency 3D flyby woosh (in both directions). Sounds much better when downloaded.
the crackling of an old scratched record
The hi pitch and noisy snare drum sound.
This one sounded to me like starlings (or you might say cicadas) when they gather in clouds I started off ...
A wonderful looping bell sequence with 5 different octaves. Deep and tense. Peace.
The sound of water going down a drain.
Train crossing in rural Texas. Recorded on iPhone 4s, processed in Reaper.