New Experiments Hint Human Language Likely Didn't Start With Grunts

Two groups of 30 volunteers across different cultures (Australian and Vanuatuan) had to try and convey specified meanings using either gestures or non-verbal vocalizations – a bit like a game of charades.

The same exercise was repeated with 10 sighted and 10 blind volunteers, who were tasked with producing the gestured or non-verbal communications, while a group of undergraduates tried to understand what they meant.

https://www.sciencealert.com/experiments-suggest-human-language-burst-onto-the-scene-with-gestures-not-grunts

Interesting take on things that are hard wired. Doesn't cover verbal communication, but interesting. I'd always thought the earliest homonin verbal communication was clicks and whistles. It would have blended with bird calls and not called attention to a species that was still a few million years away from being apex predators.

Chimps have been found to use a combination of lip smacks and blowing in face to face communication.