Dajia Hao!

i've begun studying chinese at Venice University in September 2008, and thanks to you and my will i've been able to manage chinese language (for my level of course!) greatly:everything was fine, all was heard and understood, the sky was bright and the flowers blue...
Anyway;today's lesson has shocked me, because our professor Xu(not so SLOW after all!

) has spoken with a language speed never heard before, and moreover told us that in January's exam he will speak like that...
My blood was frozen; For my experience he spoked so fast that when i was just understanding the tone of a word he had already said eight-nine other words

Results... about two hours of lesson and i've understood the 20%...
How to improve my listeninig ability?
Any ideas or source?