One of the characters in a story I'm writing is mute due to receiving intense physical trauma to the front of his neck. He had his larynx removed because of the incident and now uses sign language as his primary method of communication. The character can still hear, but is unable to speak. I'm choosing to describe him as having aphonia, as I've done some research on the topic. However, I'm still not entirely certain that I'm writing this correctly, since his situation is so specific that it's impossible to find the answer to my question on a search engine. I'd be very grateful to be told whether or not this character is believable and, if not, what I could do to alter his story.