The, perhaps originally intended, scientific answer is that no, the tree does not make a "sound". It makes sound waves, that without an instrument such as an ear, do not convert to actual sound. The common sense answer, as the question has mostly come to rely on, is that yes, it obviously makes a sound since we know that a tree falling makes noise regardless of whether anyone is around or not. The metaphysical, and perhaps first roughly proposed, answer is that no, the tree does not make a sound if no one is there to witness it falling. And indeed the act of making a sound isn't even a quandary, all that matters is that the tree in fact ceases to exist if no one is there to witness it.
Now leave me alone, I'm going outside to look for clouds that look like dunes...