Speaking purely scientifically, YES.
Regardless of the presence of any one (or thing), sound waves are produced (see below for logic); the ripping of plant cells, cracking of the timber, the rush of wind and russeling of leaves as the tree falls, the impact.
Sound is defined as waves within a specific frequency (I refer you to here for the denotative meaning).
So as long as a frequency wave (or waves) within the appropriate human range are produced, a *sound* is made.
Just my 2 cents.
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Sean Shrum
http://www.shrum.net