Only for voice .zip does it can (need to?) be .ogg; actually if you look at the codes, the API for audio seem to use .wavQuote:
Originally Posted by G-ulash [Only registered and activated users can see links. Click Here To Register...]
The .wav format is always supported and unlikely to go away. The name of audio folder needs to be correctly only if you're using a skin that required it. If not, it is to be defaulted to be under data.zip\data\ui_nextgen\audio But can be override by any new UX's or directory created under installation location.