(2/2)
As for upside down sound, let's fix this question a bit. The picture of an eye implies an analogy to light, hence why I let it take the lead so far. Why can't sound be upside down like how one can rotate or mirror an image? Sound absolutely can do this, but to let's clarify the difference in scenarios. An image is a large collection of light from different positions in space to a number of sensory positions in your eyes. Your eyes and brain have evolved to make differentiation very easy to identify. Your ears have also done so, but in a different way. Your ears sense sound through the movement of small "hairs" in your ears. If you were blindfolded and someone spoke into a megaphone, you would be unable to differentiate if the megaphone was being spoken into upright, sideways, or upside down; you would, however, be able to tell what direction the megaphone was in relation to you (barring echoes and such things from walls and junk). This is your "sound" image, the directions sounds come from in relation to your two ears respectively.
If someone rotated an LED that was always shining toward you, you wouldn't be able to tell the difference. Same with a sources of sounds. Point sources individually have no upside down or upright position because those adjectives require at least one dimension of differentiation. If listened to a rock concert or an orchestra standing up, it would sound different to you if you listened to it hanging upside down from a ceiling or while doing a handstand because what was in your left ear is now in your right, and vise-versa.
