(Sahairic) KHME, XHMT - Egypt = (Egyptian) km.tThis part is true but prove it was pronounced [ k(h)u: mat] hieroglyphics clearly doesn't mention the letter u
Ok, let's see if I can try to explain this, because it's complicated and because I realized I forgot to mention something since the beginning:
Canaaite Vowel Shift occurred sometime in Middle to Late Kingdom.
Short stressed 'u' (and e/i) merged into 'eh'
(Egyptian) d'n.t - Tanis [Tu?nat] = [Hebrew] șun > șō'an
But Akkadian - șe-e'-nu/șa-a'-nu
**Egyptian 'ď' is d with _ under it **
Long stressed 'u' turned to long 'eh' sound (according to foreign renditions of Egyptian words) :
(Egyptian) šnj - tree = (Akkadian) si - ni = [šu:n_j]
(Egyptian) hrw - servant = (Hurrian) xel = [xu:raw]
Late Egyptian 'e' then turned into Coptic 'E, Coptic 'A' and Coptic 'H', depending on dialect.
An exception to this rule of Late Egyptian 'eh' turning into 'E', 'A' and 'H' is Fayyumic :
(Fayyumic Coptic) (sh)IIM(sh)I - to worship = šemše - (Egyptian) šmsj
So according to Loprieno Antonio original Egyptian 'u' was turned into 'eh' by Middle to Late Kingdom and Coptic has rendered Egyptian 'eh' into either Coptic 'E', 'A' or 'H' depending on dialect and/or phonetic environment.
I was wrong in part of what I said because original Egyptian 'u' is sometimes rendered as 'A' in Coptic but not if it was rendered as Coptic 'H' which would be pronounced 'ee' like in English 'meat'.