What are studio ears? It's the ability to hear deep inside a track - to hear all the details, good and bad. At the beginning of a project, it's easy to hear major mistakes and flams, but it's difficult to hear the really small ones. Things that sound perfectly acceptable during week one drive me crazy by week three.
How do you develop studio ears? For me, the best way is by editing the tracks after basics. Regardless of the musicians, there are always fixes in timing that are necessary to tighten things up.
As a producer, I'm a big one for working it out during preproduction, getting it close during recording, and fixing it during editing. This keeps musicians from feeling beat up from too many takes, as long as they're playing with feeling but just not laying perfectly together. But it means that I'll have at least several days per song fixing things up later, which is where my studio ears get bigger and bigger. Now a 10 millisecond flam, which is about as little as you can perceive, will drive me crazy until I fix it.
A bad habit that many engineers and producers fall into is studio eyes, which means that you move things so they perfectly line up just because they look like they're not aligned, even though they sound perfectly fine. This is when your experience kicks in. You close you eyes and let your heart and brain take over. If it feels good, it is good!
