[Huime]

I remember someone was complaining occasion notification on their 920. While some speculate the OS does not have a notification, I were not satisfied with the answer.

I had the same problem the next day I receive the phone and it was still basically empty, which means that it can't be notification from 3rd party app. So, today it happened again and I was lucky enough to have a slow morning. I remember it gave that noise right after I slip into my pocket and the only other thing in it was my wallet. As I had always been speculating it was the nfc, I try to repeat the event. After a couple of times contacting my wallet to the part slightly lower than the camera lens, I finally got that sound again. So I picked out each card and try the same thing, and Walla! It is my Amex with Expresspay (or any contactless payment your credit card brand it) that causes the noise. It is not 100% thing, but as long as you had your screen lite up, it is possible to cause a nfc notification.

Try out guys and let me know if you get the same result.

[WorzelGummage]

Just to let you know this was discovered a while back. And yes, you are correct that if you have NFC turned on and the phone comes into contact with a contactless payment card the phone will play a sound.