I just noticed this recently when I received messages while on a call on SE. There seems to be a faint buzzing at the end of the vibration for the notification. Just wondering if it was normal or my vibration motor was failing. Really makes me miss the taptic engine on the 7. Follow the following steps if you are feeling helpful : Go into settings then into sounds - Goto Ringtone - Vibration - default - Put the phone upto your ear while its vibrating. Go back to sounds - goto text tone - goto vibration - touch the default vibration 'Staccato' - put the phone up to ear while its vibration with staccato - do you hear slight rattlish sound (very faint) towards the end of vibration?