I can't claim to be an authority on the subject, but believe that the answer varies with the medium.
The way that any language is learned is by establishing a common context that contains an understood meaning and then associating linguistic data with that meaning.
If the new language is only ever heard in isolation without any context, there is no way to learn it. Therefore, if the language is only ever heard on the Radio or in music, there is no way to learn it. If the Radio program is multilingual were a given sentence or speech is translated into a language that the listener already understands, that is different because you now have a context upon which to build meaning.
TV and Videos on the other hand are different. There you have a context to be able to extract a certain amount of meaning from the sounds. A movie could be entirely in a single language but you have the context of the scene etc upon which to build a shared meaning.