It seems that our ancestors favored short range, higher frequency speech than we do today, or our cousins the chimpanzees do now. Unbeknownst to me humans have a high range of frequencies than our good fellows of the jungle do, and this is probably because or and led to our ability to develop language, a huge leap in early man.
It seems that there was a bit of see sawing going on. As earlier human prototypes, like my favorite astralopithecus africanus, could hear in higher frequencies than either chimps or homo sapiens. In short they could hear better.
But could the speak better? Probably not, life on the savannah drove the development of their various forms of communication as the open space's do not carry sound as far. So probably a lot of chittering and chattering between the primates.
Like "CHIT CHI CHI CHU CHA" would mean "Hey Charlie, there's a leopard behind you!!"
Charlie was clearly either not listening or had his ears tuned to the homo sapien speech pattern.