Phonetic pronunciation provided by map editors would be really beneficial.
Seems like a user could suggest a phonetic pronunciation (for example, Lampasas should be lampassas, not lampahsas.) Have a way to preview what your suggested phonetic pronunciation would sound like. If you like it, submit it. Have other editors have the option to vote up the suggested pronunciation. If it receives X votes, it replaces the TTS version.
If there are regional differences (like, New Orleans), seems like multiple pronuncations could be suggested, and the vote battle would take care of which one should be used. Whatever one most people want to hear.