It doesn't really matter what we think, in terms of definition. What matters are the regulations in your area. In my country, a speech handicap classifies as a disability, and measures can be granted in that regard. - As for interviews, probably the easiest thing is to approach it as casually and straightforwardly as possible. Definitely no sense in trying to hide it, but not necessarily a reason to expressly mention it ahead of anything else either. I suppose we're looking at the notion of "natural", whatever that amounts to in the context.