Is there a name for the condition where someone moves their lips (as if they're mimicking what your saying to them), but no sound comes out? (They move their lips whenever someone speaks to them.)
Closest thing I could find was called: Echolalia . I read some on it and it sounds close to what you are describing. From Dictionary.com
meaningless repetition of another person's spoken words as a symptom of psychiatric disorder.
- repetition of speech by a child learning to talk.