Voice banking recording your voice saying various phrases that they are then able to use to make a voice that sounds more like you than any of the stock voices. the Gleason foundation will help you get started. Also your clinic may have a place to refer you. Mass General sends us to Childrens Hospital. They can do more now with small amounts of words. Google John Costello childrens Hospital Boston and watch some of his videos if you want to see some of the non standard voice banking.
i encourage you to do what you can asap. The regular process is much easier to do before you are affected so the sooner the better
Voice banking is easy, you'll be glad you did it. As Nikki said contact the Gleason foundation, they will send you the recorder and walk you through it step-by-step.