Hi, I just got a new iphone 5s. I turned OFF noise cancellation but still seems like my ears feel a bit strange at times. Is it all in my head? (haha) Has anyone compared with it on and off? Does a headset negate that feature? Maybe I'm just not used to any kind of noise cancellation, as I am coming from an older model Blackberry... tempted to go back! I have noticed it while on speaker and up to my ear. It's been pretty mild-- nothing crazy, but bothersome. Is it something you adjust to?? I was happy there was an option to turn it off. Thanks!