Seems to me, at least based on the description of "introvert" I got out of the Myers-Briggs test, that in some ways the title is relying on a misunderstanding of what introverts are.
I can absolutely talk your head off. And with close friends, there are days I will!
But I was stunned when my Myers-Briggs test results strongly put me in the introvert category.
It stressed where you get your energy. And I fit the introvert in so many ways (prefer to read over parties, go home to recharge rather than going to a party to wind up, etc).
I can only say, THIS introvert can be pretty doggone noisy in the right situation.