[Elsie]

"Nothing exists without a conscious observer.

The old tree falling in forest: repackaged.

[ETL]

The old tree falling in forest

This old thing comes up all the time as if it is so profound. A "sound" is basically a disturbance in the air that is picked up by a receiver of some sort. And if there aren't any receivers around to pick it up, no sound is made. In either case, the air disturbance still occurs.