The flaw is here:
exported as an *.mp3 file.
Why? If you edited in AU, anyway, a normal WAV will work much better.
I have the same issue with a project for which the mp3 audio was provided. I'm using After Effects CC 13.2 on a windows pc. These issues started when I updated from the CS6 version of AE.
The audio gets messed up both in the RAM preview and in the export files.
Any help would really be appreciated
Here's your help -- don't use mp3 or ANY kind of compressed audio in AE. Convert them to wav or aiff first. Compressed audio in AE has always been a crap shoot. It's just not worth the aggravation dealing with it when it's so easy to do something about it.
Consider yourself lucky that you haven't had any problems until now. Simply put, your luck has run out and it's time to face reality.
well that sucks! I used to be able to use mp3 in older versions of ae.
Sometimes mp3 is all you get from your client to work with... Also I tried converting the mp3 to .wav in Adobe Media Converter, but that came out in the same funky distorted way.
so what to do then?
Export wav or aiff from.....
Quicktime Pro (version 7.x)
any other transcoding application you can think of -- Sorenson, Telestream, what have you. There are bunches of them.