Couldn’t you just use the International Phonetic Alphabet?
Discussion
How well can people describe their own names in that?
Or is there an automatic translator from every language into the phonetic alphabet?
The thing is, when it comes to names, you can't use international phonetics because pronunciation and characters don't go hand in hand in different languages. So it's better to have an audio note where everyone record a short pronunciation of their names in their local dialects.