On Thu, 7 Feb 2013 11:31:08 -0800, Adnan Majid <[log in to unmask]> wrote:

>Hi everyone,
>If the goal of Jeff and others is just to simplify Arabic without being
>particularly tied down to Arabic's complex phonetics, I wonder whether one
>can use *vowels* to represent different consonants that were originally
>different. Many of the emphatic consonants in Arabic (as well as some
>others) cause the following vowel to become more rounded (is that the right
>term?) - namely T, Z, S, D, kh, gh, r, and q.

Rounding is a meaningful phonetic term, but I don't know of an Arabic dialect in which rounding is the relevant thing there.  Instead, it's backing: /a/ is [&] most places, but [A] in the vicinity of this set of emphatics and allies.  

>For instance, the verb "dalal" would mean "he showed" while the verb
>".Dalal" would mean "he erred." Since the "o" vowel isn't usually used in
>Arabic, one could render the the latter as "dolal", differentiating it from
>"dalal" without having to use any digraphs or diacritics. And it actually
>ends up sounding fairly similar to the original.

You've basically just reinvented Maltese!  It collapses emphatic coronals with plain ones, but the original Arabic *a is Maltese /a/ in the vicinity of the emphatics and /e/ elsewhere.  

That's as far as the phonemic splits go in Maltese, but cross-linguistically vowel lowering near uvulars and pharyngeals is also extremely common.  So the sensible way to extend this approach to all the original Arabic vowels, I would think, would be *a i u being [A e o] near emphatics and [& i u] elsewhere.  (Not these strange front rounded things.)