Jazz Ear Training from Tom van der Geld seems to be a nice book to use in classes at the conservatory. And in fact; it is usable as such, but only in a preperatory class. For use in the actual ear-training classes the level of the exercises isn't quite high enough. Nevertheless, a few of the exercises are usable, but as a stand-alone method it lacks the desired level.
As for the cd's: they are a nice addition, but it would have been better if they would have been made available through a site, because in that way the teacher can make better use of it in the classroom.
The book is made in a bilingual way; every page is divided into to columns, where the left one is in German, and the right column gives the same textual content in English. It may be clear that this isn't usefull at all, because I never come across a situation where I need to explain something in German, because either me or my students don't understand it in English. Off course, seen that the author is German, it seems logical that there is a German version, but it would have been much better to keep that in seperate books, if it isn't just for the loss of pages.
Conclusively; this book can be nice for an amateur, who wants to improve his aural skills; or to prepare oneself for a study at the conservatory, but for use by professional teachers at a conservatory it lacks the desired level. At the last page of the book there is mentioned that there will be al volume 2. I wasn't able to find such a volume 2; but perhaps this volume 2 will be better suitable.