Language is an interesting topic for me. What I have never seen is people trying to put together a history of sound. This normally falls into the abstract "historical linguistics"
History of Human Language
Sounds can be grouped in families. These families of sounds may indicate that the various sounds evolved together at the same time.
Perhaps the sounds used at this time are not the original sounds used by the early sapiens or erectus.
The best approach to understanding the history of the sounds used in language is to look at the earliest writing. Where there any sounds that happened after writing? (I think a,w [th in these])
Another approach to putting together a history of sounds used in language is to put together the families of sounds. New sounds must have caused conflict and shock (as they do even now) and perhaps the shock was less when the sounds sounded similar to sounds made earlier.
Important questions are:
Were the first vowels used by australiopiths, homo eretus, neander, and or only with sapiens?
Where did oral language start?
Do other species have language?
How many base sounds do other species use?
Was the language brought with sapiens to the Americas (10,000 years before now) already completely formed in Asia?
What is the complete list of sounds used by the first humans in the Americas?
1) Most of the sounds used in human language were already invented 10,000 years before now, or whenever the first humans entered the Americas, because the chances of reproducing the same sounds already in use in Asia and Europe (convergence), are low considering the number of sounds possible.
~500,000 years before now?
Second vowels (I can only guess)
Early/First Consonents (all in the same TDKG family)
Secondary consonents (in same PB family)
P (pot, ptolomy, paper)
Third consonents (in same SF family)
Fourth consonents (in same LRMN family)
here I can only do more guessing
Fifth consonents (in same WY family)
Sixth consonents (in same SF family)
H (hot,house) (sf family?)
h (phlem h)
Later or fourth vowels
Last of the consonents
w (this, these)
History of Letters
History of Words
Tree of language
(from "Introduction to Historical Linguistics", Anthony Arlotto)