Sometimes a 'regional' accent or an odd twang in someone's voice can be a positive thing ... as long as the words are enunciated.
In the military, in an environment where spoofing is available to an enemy, a distinctive accent may be impossible to immitate.
Isn't there a post somewhere on here where a Phantom mate queries his pilot about whether he is going to authenticate a controller's instruction? His response is to the effect of "No need, I've sh@gged her!"
Ah yes, here it is:
Thanks Beagle!
IMHO, in general, regional accents aren't a problem, but stammers, on the other hand ...
Regards
STH