[sliverstorm]

it is possible to find a dataset where the audience actually doesn't need to stop the speaker because they can tune in to the way english is spoken.

Of course. But again, what does that really tell us? To be effective, you need to be able to communicate with a large variety of people, not just a carefully-chosen subset of people. As Indira acknowledges, it is your own responsibility to ensure this- not your listeners.

I've met people in America with accents almost this unintelligible: http://www.youtube.com/watch?v=I5XyecKONu8 (although typically their mother tongue was of Asian lineage so the sound was different)