I purchased a used Canon 70-200mm L series lens with IS. When the shutter is half way pressed you can easily hear the IS working, but should I be able to hear it easily? I have read wear others have to put their lens near their ear to hear it, not mine, it is heard easily. I have the 18-55 lens with IS that came with the camera and you can't hear it. I'm thinking you shouldn't be able to hear it. Interested in hearing from others with this lens.