[Livia]

Originally Posted by Toy Soldier

Bewilderingly - there are actually some very current studies going on in theoretical physics that appear to show that there are aspects of existence that behave differently depending on whether or not they're being actively observed. Crazy stuff.

As for the "make a sound" question at its most basic level it's just semantics. The tree falling makes sound waves, so it depends on whether you call that effect itself "sound", or if you call the human brain's interpretation of those waves "sound". Most insects etc. actually perceive sound in a totally different way to mammals etc, feeling the vibrations (which we can also do, but to a much lesser extent) rather than actually "hearing" as we understand it.

Erm... thanks.