When a person is looking for a way to communicate in alternative ways, they need to find something that really works for them. They need to try to find a voice that sounds natural. They want to try to find a way to be efficient. They want to be able to communicate as normally as possible, even though they're not using their biological voice.
A speech language pathologist is someone who is trained in working with kids and adults. Everything from working with articulation errors and correcting things to what I do, which is working with people with profound physical impairments and getting them augmentative communication strategies.
Upper limb therapies and interventions have been well studied in cerebral palsy. Different interventions that have good evidence are Constraint Induced Movement Therapy (CIMT) and Bimanual Therapy. CIMT has been shown to be successful in children with hemiplegic cerebral palsy (CP). CIMT uses a splint to physically constrain the uninvolved arm and encourage them to use the more involved or affected arm.