Regional TitleBG packs
Regional TitleBG packs (named with the format TitleBG_XXxx.pack, where XX is the region code and xx the language code)) are SARC archives which are found in Content/Pack. They are similar to the normal TitleBG.pack, but contain files that are used in specific languages.
TitleBG_XXxx.pack
Voice
The Voice directory contains voice acting audio files.