I'm sure Bill Parry is a wonderful man. I've never met him. But the hypothesis is crap. I just leads people who don't know about stuttering to the wrong conclusion. In my opinion it reinforces the idea that "stuttering something that happens to me" instead of "stuttering is something I do." (e.g., bystander v. active agent). And you're absolutely right about HCRI being more rigid. (But that's a therapy protocol and not a hypothesis of stuttering). Maybe I've never been clear. The therapy in the Valsalva Hypothesis is fine, but the scientific hypothesis behind how the Valsalva Maneuver causes stuttering is crap.