umm...I'm just starting this page because I don't want to have to remember to link to it from GoldWave in the future when someone does make this page. :)
Oh... What the hell... I'll even start you off:
the .uax extension is for UT's internal sound package file format... It contains sounds much like .utx files contain textures and shaders, and .usx files contain static meshes. Is anymore explaination required? this is all I know about it.