There is no protection on the CD. The discs are in fact ordinary now obsolete Philips CD-I format. The disc uses the standard XA Mode2 Form2 format and the Philips RTOS file system. Problem is that CD-I discs are like boot discs and actually holds software that run's on a CD-I machine, so data could be in any format.

But, lucky for u guys, AEI music CD's have the audio part in raw ADPCM 37800Hz (37.8kHz) format. Same as raw audio samples on a CDDA, but at a little lower sampling rate, and it's interleaved because of XA format.

If you can rip out the MUSIC file as raw 2352 bytes using ISOBuster, then you're in luck, as you can use a program called PSmplay to listen or to convert to wav file.