'Audio files that you download from the internet' could be absolutely anything - a song, an opera, a news broadcast, a test signal, a play... tells you nothing.

'Audio files that you download from the internet' could be absolutely anything - a song, an opera, a news broadcast, a test signal, a play... tells you nothing. 'Podcast' gives you a general idea of the medium and intent. That's useful. Otherwise we might as well call everything in the universe 'stuff' if you really don't like nouns that may have a slight overlap.