Doesn't it depend on the language? I've picked up quite a bit of Spanish late in life and I think it came fairly easily. Granted, it helps to be in CA where Spanish is quite pervasive.

I'm now trying to pick up conversational Vietnamese and, wow, that is a whole different ball game. Tonal languages are full of subtleties that don't come easy to someone who has never paid attention to them. It feels like I'm trying to learn perfect pitch.