Communication

Bob is really struggling with speech again. I try to keep questions short and to the point. One question or phrase at a time. Bob either wont answer or he answers in his head without actually speaking the words.
 Today I asked him a question and was waiting for a response. Nothing. I repeated it a few more times. Still no response. I asked him yet again and said.. Are you understanding me?
 He said "Yes- MY answer is still the same"