Are you kidding me? Not in my experience. Those who say that statement "we're _D_eaf - we don't need to learn English" are CAPITAL-D deaf. How many little-d deaf students say that? Isn't there a high correlation between those who are capital-D and having family or early exposure to deaf culture?
They shouldn't be experiencing this so-called "language barrier."
It's just an excuse to lower expectations and not perform well in school.