Alright I think I've found what you're looking for. By EB's commencement in 272 BCE, Phoenician-Punic had merged the fricative sh into s by the 5th century BCE, and had merged the grapheme Š into S by the 4th. Here's the section we are concerned with:
Krahmalkov, C.R. A Phoenician-Punic Grammar.Š: /ś/ = [s], the reflex of PWS /θ š ś/: these phonemes had early merged in Phoenician into a single bilateral fricative, hence the existence in Phoenician alphabet of a single grapheme. In Classical Phoenician, the fricative merged with simple /s/ (expressed by the grapheme S) but normally continued to be represented in the orthography by the grapheme Š; the merging is exhibited in the 5th century Phoenician spelling 'SR for etymological 'ŠR in the Esmunazor inscription from Sidon (KAI 14.1). That Phoenician did not possess [š] is confirmed by Augustine (Epis. ad Rom. inch. Exp. 13) in a word-play between the Punic numeral salus salūs (ŠLŠ "three, Trinity") and Latin salus ("salvation") that indicates that the numeral was pronounced salūs, not šalūš (Hebrew šalōš).
He follows with an example of a 4th century Punic poem that illustrates the consolidation into simple s.
So basically, whether or not it was written s or sh, the Punic was pronounced with the/s/. I hope that answers your question. I was not surprised to find the texts on Phoenician alongside those on Modern Hebrew, but I'm surprised to learn that the fricative merged into the simple sibilant quite early on.
By the way, the linguist calls it a lateral groove fricative. So this isn't the central fricative sh as we know it (e.g., the first sound in English 'shoe'). The only lateral in English is the /l/ as in the first sound in 'ladder'. They are so-called laterals because the airstream is released on either or both sides of the tongue, not centrally. I looked at Wikipedia's article "Phoenician language" under the phonology section and it only mentions that linguists/scholars debate whether the š was a sh (as in 'shoe') or a s (as in 'salt'). Of course, neither of these are lateral fricatives and I don't know of any language today that uses a lateral groove fricative.
EDIT: Just came across this consonant chart. I find it much easier to follow if you can read such charts. It illustrates how the two graphemes, whether or not they were used distinctly in the writing system, were pronounced identically in spoken Phoenician. It should clear that up for ye!
http://ancientlanguages.wikia.com/wi...cian:Phonology
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