Maybe some sounds are stored in the OBB? If I remember correctly most OBBs are just zip files, in which case it should be easy to extract. The OBBs can be found @ \sdcard\android\obb\[package name of app]
The CKB contains neither WAV nor OTO files. It’s some custom (?) archive format where sound data is stored as one continuous stream while the length and samplerate information is part of the offset table at the beginning of the file. My converter does not "extract" WAV files but it creates them from the data available. The same applies to many other games and custom formats.