http://designingsound.org/2017/02/sunday-sound-thought-58-the-sounds-that-arent-there/
What is the sound of one hand clapping? I remember the day I figured out this riddle as a wee youth, only to see it replicated on an episode of the Simpsons shortly thereafter. Bart and I both thought alike: a clap does not need two hands to make sound, one hand can clap and make a pleasantly fleshy soft impact sound. If a tree falls in the woods and no one is there to hear it, does it make a sound? I am a very rational, logical person (excessively so according to my girlfriend), and I always considered this riddle just plain dumb. Of course it makes a sound! Our brains and ears do not create sound (except perhaps in tinnitus and hallucinations), we merely interpret and filter the waves bouncing around us.
Interesting note:
Our ears DO make a sound! See Maryanne Amacher and Jacob Kirkegaard