I'm currently investigating on how to rip them with the files themselves, since BBCF just won't run on my PC, same as a few other games (and the issue already went on weeks ago).
For now, I've tried the importation to Audacity through raw files after having extracted the vbtl_es_0.xwb file (for Es here) using Hipster. (IIRC there was a way using the Microsoft XAct utilities in the Jun 2010 DirectX folder package you can find on the Internet, but honestly, I don't find the way to open the Wave bank again (if there was any to start with))
I've picked the following parameters :
Encoding : Signed 32 bit PCM
Bit order : little-endian
Channels : 2 (Stereo)
Offset : 0 octets
Sample frequency : 44100 Hz
After having modified the speed with the multiplier x0.26, I've retrieved the voice clips of Es in battle, but they don't seem to have the best quality. Perhaps I should tweak a few more parameters to get something good, but in the meanwhile, I give you the .wav file with all the voice clips within the .xwb file, so you can see the current quality I got from it, and judge if it's good enough or not. https://www.dropbox.com/s/g71jwwo2va18owx/vbtl_es_0.rar?dl=0