For quite a while now I've always been puzzled by a strange seemingly random tone coming from my phone when turning off the alarm in the morning. I place the phone on top of my wallet and in the morning when the alarm goes off I turn the alarm off only to sometimes be greeted by the strange beeping tones.

I always thought it was due to some sort of bug, as it was never really consistent. Well, today I've just found out courtesy of WinBeta that this is due to NFC as shown in the following video and thus the mystery is finally solved. So if you too ever wondered what the strange tones were, well now you know.