Felt Tips posts another great tutorial diving into After Effects expressions with this look at creating a great workflow tool for working with and synchronizing audio. The final expression will allow you to tap out the timing of the audio using the keyboard, adding markers that will be used for the synchronization.
In this tutorial, you’ll see how to create an expression that synchronizes sound across compositionsFelt Tips - AEtuts.com
The video will run through conceiving, breaking dow, and structuring the expressions, using a debugging text layer that was previously covered in another After Effects Expressions tutorial. As a note, the tutorial is aimed at intermediate to advanced users who have an understanding for using expressions in AE already, and are looking to expand onto the next steps. Check out the tutorial for Synchronizing Audio Across Compositions with Expressions here.