The mouthing of the words is only a test. It is to demonstrate that stuttering is not in your mouth but rather in your voice. A fluent speaker doesn’t stutter because they have a steady flow of air through the vocal cords during speech. The stutterer has little or no airflow which I strongly believe is the root of stuttering. Once a stutterer learns to maintain smooth and steady airflow they are on the path to fluency. I am a speech pathologist where my expertise is in brain based learning I was actually able to rewire my brain into a fluent brain. It is a lot of understanding of airflow and a lot of practice. This resulted in me becoming virtually stutter free. I would like to think that anyone can replicate my success. Truthfully I really don’t know.