The definition of sound is kinetic energy causing the molecules
in the air to vibrate, compressing and releasing, creating a wave.
This wave would hit a sound receptor, in this case our eardrum. The
ear drum would cause liquid in the cochlear to vibrate, which
causes hairs in our cochlear to vibrate. These signals would be
sent as electrical pulses to our brain, which translates it as
sounds.
So it creates sound energy (vibrating air molecules) but no one
hears them.
Ok, I put it to you this way. Say you're indoor, in a room with no
view outside. I can see the moon, I say the moon exists. You can't
see the moon, so you say the moon doesn't exist? 
Say a tree falls in the forest, but you're not there to see or hear
it, does it fall?
