Phone makes sound when waving a credit card near it I have a Samsung Galaxy S3 and the phone was in my pocket. I forgot that my credit card was also in the same pocket and just out of nowhere my phone played the notification sound, so I pulled it out of my pocket and there were no notifications; no new email or SMS, nothing.

So then I pulled the card out and swiped it near the back of my phone, and then the sound played again. I did it like 20 times and it always happens. Why does my phone play the notification sound when I wave the credit card at the back of it?
Does your credit card have an NFC chip? The phone can read and write NFC data. It is probably activating Android Beam or S Beam.