Phone noise

[AC Question]

Why does my Galaxy S5 make a tinkling sound? The phone is on, in my pocket and I hear the sound "tink tink" I check the phone and the screen is dark. I open the home screen, nothing, I check the phone, nothing, I check the messages... nothing.. What up?
Thanks for your help.

 

[belodion]

If you don't already, try keeping your phone in a pocket by itself...something else in the same pocket may be responsible.

Posted via Android Central App

 

[belodion]

...I mean something having an electronic effect on the phone, not tapping against it.

Posted via Android Central App

 

[B. Diddy]

Could potentially be something with an NFC chip. Is it near any credit cards when you hear the tone?