I am trying to work with AE and sounds.
But the only way that I've found to that is the RAM rendering...
How can I work with video if I don't listen anything to cut where I should cut.
First thing about AE- it's not designed to work with audio or edit. For that use Premiere Pro or FCP.
If you need to play the audio and set markers, you can just hit the "." key from the numeric pad for playback and the "*" key from the num pad for setting markers.