I find this lens quite noisy. I gather it is mainly caused by the OIS which is active whether in use or not. When switched off the lens still has to hold the moving lens element in place by a magetic force. I am on to my second lens as my original one was far louder which had a high pitch whistle (very annoying!) and the OIS tended to create unexpected "jumps" when it should not have. This fault developed after a month after getting the lens. My current lens still makes a noise- more a quiet churning sound and so far no hiccups on the OIS. Optica wise a nice lens. Noise and OIS a bit of a mixed bag!!