Really? Are these non-European languages that you're referring to, because many of the European languages have their own versions of the name Alexander for both men and women, so I'd imagine Alexa wouldn't cause too many issues.
The 'x' in 'Alexander' is (typically) voiced, where that in 'Alexa' is not. I can see that making a substantial difference for speakers of languages where those phonemes are differently composed.
What do you mean by voiced? I put the stress differently, but otherwise I would pronounce Alexa as Alexander cut short. I can imagine the vowels being pronounced differently in various accents, but I can't imagine an accent where the 'x' in those two names are different.
"Voiced" in the phonetic sense [1], i.e., spoken with the vocal cords vibrating. Voiced 'x' sounds like the /gz/ in "eggs", /ɛgz/; voiceless 'x' sounds like the /ks/ in the American English pronunciation of 'x' itself, /ɛks/.
Many, if not all, American English dialects pronounce the words in the fashion I describe. In them, the name 'Alexander' would be
/ˌæ.lɛˈ(gz)æn.dər/
while 'Alexa' would be
/əˈlɛ.(ks)ə/
- in both of which, the phoneme corresponding to the letter 'x' is parenthesized.
Generally in English 'x' is voiced when it precedes a stressed vowel, which it does in 'Alexander'; in 'Alexa', 'x' precedes a reduced vowel, and therefore would always take the unvoiced pronunciation. (It'd sound very odd to an anglophone ear otherwise - say /əˈlɛ.gzə/ one time out loud and see if you don't feel the same.)
That said, it wouldn't be incorrect to pronounce 'Alexander' in American English with an unvoiced 'x', as
/ˌæ.lɛˈksæn.dər/
but, while I believe some dialects of English may default to this pronunciation, certainly not all do. (Neither of the dialects I speak does so, at the very least.) This pronunciation also produces a "hitch" or break in the word between the unvoiced 'x' and its preceding vowel, which would tend to make it a little odd both to hear and to say.
> I put the stress differently, but otherwise I would pronounce Alexa as Alexander cut short.
In “Alexander”, the normal pronunciation of the letter “x” is the voiced consonant cluster /gz/, in “Alexa”, it's usually the unvoiced cluster /ks/. (Also, the second “a” is usually different between the two, being /æ/, like the “a” in “pad”, in “Alexander” and /ɑ:/, like the “a” in “father”, in “Alexa”.)
The difference in the “x” is the normal way that the pronunciation of “x” differs when following a stressed vs. unstressed vowel in English.
