Researchers at the University of Amsterdam in the Netherlands created air sacs from plastic tubes to figure out how early man might have sounded:

All primates have an air sac except humans, in whom it has shrunk to a vestigial organ. Palaeontologists can date when our ancestors lost the organ, as the tissue attaches to a skeletal feature called the hyoid bulla, which is absent in humans. “Lucy’s baby”, an Australopithecus afarensis girl who lived 3.3 million years ago, had a hyoid bulla; but by the time Homo heidelbergensis arrived on the scene 600,000 years ago, air sacs were a thing of the past.

So, the part I was the most interested in, what would the first “words” have been?

With air sacs, vowels tend to sound like the “u” in “ugg”. But studies suggest it is easier to produce a consonant plus a vowel, and “d” is easier to form with “u”. “Drawing it all together, I think it is likely cavemen and cavewomen said ‘duh’ before they said ‘ugg’,” says de Boer.

That’s right.  The first word was, “duh”.  Makes sense.

[Via New Scientist]