It is a great article about Valsalva response but it will not help someone who stutters. The breathing you do for speech is very similar to the breathing you do when you sleep. Your lungs need to passively open and close while your Valsalva is relaxed. Stuttering occurs in your throat and not your mouth. Try talking with no breath by just mouthing the words and you will eliminate your stuttering. You need to get the brain to understand the meaning of fluency. This is why a fluent brain does not stutter.