If you know about Dragon Ball and lost media, you will know that a company called Harmony Gold dubbed the first and third movies from the series and about 5 episodes. The 2 movies are the only ones that are found.
However, according to people on the DB forum Kanzenshuu, Harmony Gold still has an audio tape in their vault and it would likely cost about $500 or more to buy the tape, have it baked and make the audio accessible. We nor Harmony Gold have any idea what's on the tape besides music, probably.