Cindy,

It must be very frustrating for you. My experience is my son is hard of hearing and when he does not wear his hearing aids it is so maddening to have to repeat and repeat so I get it.

There is SO much advancement in technology every day, if I was you, I would be scouring around to find where the latest medical devices are being developed to improve synthetic speech. There must be numerous efforts out there doing this. See if you can get involved with one of their programs. Good luck.