This is actually a question related to the question about Hannibal by /u/commiepanko11 . How far back does our knowledge of phonology go?
There are a few historical linguistics experts here, but this question may be worth x-posting to a linguistics sub (e.g. in the sticked Q&A post in /r/Linguistics). Meanwhile, to get you started there have been several posts on pronunciation of some ancient languages here
.. plus this more recent comment on Ancient Egyptian