Neanderthals had different bodies than we do. In general, they were stockier and shorter, for instance. And there were other physical differences, as well. It's hard to say what these differences meant in practice but it's fun to speculate. You could build up a pretty good about how those short, study bodies might have helped Neanderthals be better adapted to cold. Or, you could look at the shape of a male Neanderthal's voice box, and think about how that shape might affect the sounds that came out.
So that's what this video is about. I have no idea how widely accepted "high pitched voice theory" is. I couldn't find a lot of references to it outside of the BBC special this clip comes from. Here's what the BBC says:
Professor Bob Franciscus, from Iowa University, is part of a multi-national group attempting to do just that. By making scans of modern humans, he saw how the soft tissue of the vocal tracts depends on the position of the hyoid bone and the anchoring sites on the skull. Computer predictions were then be made to determine the shape of the modern human vocal tract from bone data alone. The same equations were then used with data from a Neanderthal skull to predict the shape of a Neanderthal vocal tract.
The Neanderthal vocal tract seems to have been shorter and wider than a modern male human's, closer to that found today in modern human females. It's possible, then, that Neanderthal males had higher pitched voices than we might have expected. Together with a big chest, mouth, and huge nasal cavity, a big, harsh, high, sound might have resulted. But, crucially, the anatomy of the vocal tract is close enough to that of modern humans to indicate that anatomically there was no reason why Neanderthal could not have produced the complex range of sounds needed for speech.
As long as you understand that context, that this isn't necessarily a given that Neanderthals spoke in high-pitched voices, I think you should see this video. Because the results of this theory are damned hilarious.
Via misspepper on Submitterator!