What did Proto-Indo-European sound like? It's a fascinating question. The reconstructed language is one of the most important languages in human pre-history - yet we are able to hear what it sounded like with some accuracy roughly 7000 years later! Historical linguistics enables us to hear with our ears the world of yesteryear.
Happily, linguist Andrew Byrd has made several audio readings of fables in Proto-Indo-European (PIE). PIE is probably the most fully reconstructed PL2 today (or PL3 if you get really pedantic, since Latin < Proto-Italic < Proto-Italo-Faliscan < PIE). Anyway, enough of my yakking.