I got myself a brand new Zuiko 75/1.8.
I'm happy with it as it performs as expected (excellent image quality, sturdy build). But...
Before buying it I did my home-work and learned the AF is silent. Now this copy I got today isn't really silent. It is, for the most of the time but there is a also a medium to medium high pitch whirring sound involved in the process. I hear it, clearly, whenever turning the camera on or off and when the lens hunts for focus or when it goes from long distance to short distance.
This is with an E-M5. Is your copy the same? I'm not that bothered as I don't shoot video but would like to be an owner of a normal copy.