[PatrickHenry]

Good research. It seems that we may never know. Interesting speculation, however.

[longshadow]

Another factor to consider: even if the Neanderthal had teh capacity for speaking, and even if they did "speak" to each other, that does not necessarily qualify as a language.

As Richard Mitchell (The Underground Grammarian, "Less than Words can Say") once noted, a vocabulary that consists of 75 synonyms for copulation does not a language make. While his remark was originally intended as a rebuttal to the laughable claim that Ebonics was a legitimate language, it seems equally applicable to putative proto-languages of Neanderthal.

A language is something more than one "grunt" for "one," two "grunts" for "two", etc., and shouting "ugga-ugga-UGGA!" while pointing at an object to denote "MINE!"