I've always hated that "question". A tree that falls in the forest does make a sound, because there will be something there nearby capable of perceiving it, even if not a human. It's a forest, there will be birds, small mammals, insects - something will hear the tree fall. A better question would be something akin to "if a satellite exploded in the depths of space, would it make a sound?" to which the answer is of course no, as the vibrations would dissipate long before they could be picked up by anything with auditory receptors.
But cute moment nonetheless I guess.