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.
As your child with CP is becoming a teenager, there are a couple of things you may want to think about.
The typical cognitive assessments that are used for children require them to be able to use their hands to point to pictures or hold puzzle pieces.
For a child with CP learning to move, the really important things to remember are that the child should always be active.