No idea about Arabic in particular, but there is no better way to learn than practice and then practice some more. I use a lot of tapes (students get used to my own voice quickly)-- some that go with books, and some of my own. To avoid passivity (or downright snoring), there must be a task or tasks attached: repeat or take dictation as a minimum, gapping or answer questions, fill in graphs, choose the correct picture, top-down understanding, bottom-up undertanding, etc. etc. There are a number of good texts out there, but be sure to listen to the tape before you buy or borrow, to be sure it is of native or fluent speakers at normal speed, and with reasonably authentic dialogue.
The main problem is expecting too much from beginners, moving too fast, and underusing the material. Work through it word by word if you have to, until they understand what they have been listening to. They need to be challenged, of course, but challenged at their level.
That's my quickie overview.