I've been speaking publicly since I was little kid. And at university my CS program required exactly one theater class, not any theater class but... you guessed

I've been speaking publicly since I was little kid. And at university my CS program required exactly one theater class, not any theater class but... you guessed it, public speaking. There are a lot of great ways to learn how to be a good public speaker and everyone should try to improve, however I have never heard of this throat vs mouth thing. I am not saying it's not true, I've never tried it. All I am saying is, there is a plethora of resources on public speaking and this is just one of them. If it doesn't work for you, don't get discouraged. Another possible explanation for British vs American speaking might be cultural. I am not sure about British school but in a lot of European schools, oral exams are just as much part of the daily curriculum as pop quizzes are in American. Add to that a difference is how positively or negative a culture views "aahs" and "uhhms", and that can explain a lot.