Render settings for audio for film in After Effects

Hi there,

I am trying to export my film with dialogue. My original audio file is in WAV which is CRISP! And when I add it to the video in AE and export it, it reduces in quality atleast 10x!

When I rendered it in quicktime with uncompressed codec, it turned out pretty close to the original.

But the file size was.....3GB!! (The film is 7 minutes long). But when I render it using H.264 using AAC, the audio sounds horrible and rough.

Also, which audio codec do I use? What's the difference between AAC, AAC Version 1 and AAC Version 2? How can I reduce the file size without losing out on SO MUCH quality?

Thanks for the help in advance!

Cheers,

Nikhita

P.S: I have used 48KHz, Stereo and 32 float for the original as well as the export settings. It's the codec that's messing things up. So help!