I don't mean to be cynical, but given how simple the premise of this 8 week speech program is, As well as the fact that there have been studies on this from as early as 2011-2015, if it really resulted in meaningful long-term changes in a statistically significant number of people, surely this would have been adopted in mainstream speech therapy by now right? I'm just surprised that it's my first time hearing of a practice method like this.