I just got an iPhone 4S, an upgrade from my iPhone 4. I'm using it and one thing I'm noticing is the vibration is weird. Not sure if it's defective or just different. Anyway, the quick vibration when plugging into a power source sounds much quieter, to the point of almost being unnoticeable. However, when there's a long vibration for a call or an alarm, the phone makes an audible buzzing sound in addition to the vibration. For the long vibration, the vibration sounds louder but softer than my 4. So did Apple just change the vibrator, or is something wrong with my phone? I guess my main worry is that this change in vibration could be a signal that the motor is going and I don't want to have that happen.