I know this may sound simple but I just can't master it. I want to slow down the audio at the same rate as the Video.
I'm using the video envelope to slow the video but I also want the audio to slow down proportionally.
Well, assuming you've slowed down the entire video event to a constant speed, and then stretched the end out to show the entire event, you can simply Ctrl-drag the end of the audio portion to the same length and theoretically it will line up. That's a lot of assumptions though. If you've slowed down less than the full clip then you'll probably have to insert splits in the audio event and stretch that section out separately from the rest. If you have varying velocities then you're pretty much stuck. You could put many splits in during the velocity change and fudge each little piece out. If you do that carefully enough it way work ok.
Thanks Chienworks but when I do that, the audio doesn't change pitch - I want the audio to slow down to a lower pitch at the same time or speed up like chipmunks. What am I missing?
After stretching the audio, right-mouse-button click on the event, choose Properties, and under Time stretch / pitch shift change the Method to Change length and pitch.