I'm late to the discussion.....you mentioned earlier "vocal therapists". Were they speech therapists by chance? (SLP = Speech Language Pathologist)
My DW is one....so that's the first thing I thought of reading this. Her focus is primarily in a different area though.... and sleeping now so I can't ask her about it at the moment....
Regardless, looks like you have made contact with the right people....and I wish you luck with it.
ugh, unintended consequences....