Can I listen to the whole Listening examination to check it before I play it to my candidates in the examination for for IGCSE German Foreign Language (0525/7159)??

No. You should spot-check the listening examination for recording and sound quality when you receive it by listening to short excerpts. Then, in order to check the acoustics, the recording should be spot-checked in the examination room one working day before the examination. On neither of the above occasions may the recording be listened to in full.