[musik_maniak]

Originally Posted by Author85

So, that's how I do it, and I always make an absolutely perfect synch, down to the microsecond, for my audio re-authors. If anybody has an easier way, please let me know, as I haven't found a way to do it any better without the benefit of audio/video timecodes.

Thanks Author85, for an interesting post. I learned a couple of things.
It seems like a very precise method, and probably the way it should be done.

IMO, I've had good success using a method, which is obviously not as much work as what you put into it:
First of all, I make sure the sync of the original audio track is right on. If it's not, I'll fix it with TMPGEnc or something similar.
Then I extract the audio track and open it up in Cool Edit. I pick two obvious downbeats in the music; one at the beginning of the recording, and one at the end. Using the waveform peaks, I measure the exact time between those those two downbeats.
Then I open up the new audio track in Cool Edit and find the same two (beginning and end) downbeats. I adjust the speed of the new audio track (by changing the pitch in Cool Edit) until the time between those two downbeats is exactly the same as it is on the original track. This ensures that the new audio runs at the same speed (pitch).
In order to get the new track to start at the same time as the old one, I measure the time between the start of the original audio track and the first downbeat that I had selected (the "beginning" one). I then trim the beginning of the new audio track so it matches this. (I also trim the end of the new audio track, but obviously, the end portion is not as critical as the beginning.)
So that usually gives me a new audio track that is identical to the original, as far as sync is concerned.
Granted, if the audio speed varies on either the new or the old track, it would present problems, but if not, this method seems to work fine.