Create a new downloadable voice as part of the mainstream Voice Assist Utililty

I would like to contact a developer on the SSML team regarding the possibility to create a new downloadable voice, in a language yet unsupported. I don't mind making a free contribution. Creating Custom voices does not seem to be a solution, since only English is supported when creating a custom voice.

Create a new downloadable voice as part of the mainstream Voice Assist Utililty
 
 
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