There should be a way to determine as to whether a (community) course contains audio. The only way that I know of to find out is to actually start a course.
That said, there should also be a means to filter courses. Depending on the lanugage, there is tons of courses, particularly ones for beginners. It would make things so much easier if courses were grouped into levels, such as A1 …C2.
Now I do know that this isn’t easy as it would mean that existing courses would be missing a level, but if there was (also!) something like a search-feature, it would sure make things a whole lot better!