Walter Murch is a film editing guru; he's cut films from Apocalypse Now to Cold Mountain, but he's almost as well known for his genius in explaining the techical and neurological mysteries of editing and sound. He's doing just that at transom.org, an audio/radio art site, where he makes his case for sound as the most elemental of all the senses:
Hearing is the first of our senses to be switched on, four-and-a-half months after we are conceived. And for the rest of our time in the wombˇanother four-and-a-half monthsˇwe are pickled in a rich brine of sound that permeates and nourishes our developing consciousness: the intimate and varied pulses of our mother's heart and breath; her song and voice; the low rumbling and sudden flights of her intestinal trumpeting; the sudden, mysterious, alluring or frightening fragments of the outside world ˇ all of these swirl ceaselessly around the womb-bound child, with no competition from dormant Sight, Smell, Taste or Touch...The discussion quickly moves into how an audience perceives layers of sounds and effects in a film, but it starts with an mp3 of "Womb Tone," recorded by Murch's wife--a former midwife--Aggie.
...One of the infant's first discoveries about the outside world is silence, which was never experienced in the womb. In later life, the absence of sound may come to seem a blessed relief, but for the newly-born, silence must be intensely threatening, with its implications of cessation and death.
Womb Tone, Walter Murch's guest talk [transom.org]