This is basically a legacy placeholder now in regard to wave files, there can even be references to aviation warnings such as terrain and sink rate. Older auto devices made practical use of wave sound files (*.wav) for spoken warnings and i think perhaps Language Guides (translation lexicon) and maybe Audio Books too - i'm hazy on it as haven't had to think about that stuff for many years.

That test page is there to identify problem files and test and adjust, don't worry about it unduly. It's not saying there's any incompatible audio file loaded, that's identifying the test phrase it would play ("Play Phrase", top LH corner) if the corresponding wave file was loaded. Press Up or Down to see other test phrases but if they aren't loaded they can't be played.

If you press "Aud Ver" in top RH corner it'll show you .vpm voice guidance files for navigation on the next page.