I would opt for no words as well, too much of a distraction.
It's not everyone's thing, but there is an album called "Officium", which has a rather unusual mix of renaissance choral music and jazz saxophone - it sounds totally weird, and in a way it is, but it is soft, and very soothing and relaxing. Might be worth a go. I would also advocate Enya, or if you like that sort of thing, any celtic compilation CDs
Hope it goes well