The current information we can enter for audio tracks doesn't always tell the whole story. For instance, The Osbournes has two English audio tracks, with bleeps and without. M*A*S*H is available with or without the laugh track. Most releases of Ghost in the Shell 2: Innocence contain two English dubs. Mad Max has both Australian and American English audio tracks. Several anime titles whose rights bounced around over the years got multiple dubs and sometimes include both. In DVD Profiler, these all show just as several identical English tracks for no apparent reason. It would make things way more informative if we could add a short note. (We could put in the rules to only use this if necessary.)

This also has other uses. You could tell what language commentaries and descriptive audio tracks are in, distinguish between the piano, theater organ and orchestral scores often offered on silent films (currently all would be music only) and explain what is up with tracks currently listed as other, which could be anything. Multiple dubs happen in other languages, too and we could use this to explain why Harry Potter and the Goblet of Fire has two each French and Spanish dubs, for instance.

If we ever get a proper special features field (where we can list all of the special features — names of featurettes, commentary participants, etc.), that could be a possible spot for it, adding something like "Includes both the Australian and American English audio tracks."

To do it in audio, we'd have to either: A.) replace the drop down menu with a text entering field, sort of like the Studios field, which would be good to allow those multiple language tracks (such as the ones that say "In Serbian, Croatian and Russian") and for commentary tracks ("Commentary by director Martin Scorsese").  You could add "English (Australian)" and "English (American)" or "Spanish (Latin)" and Spanish "Castilian"); B.) Or, as you alluded to, add a comments field to the side of the track.