How do I stop a continuous alert tone which alerts even when there is nothing to alert

[AC Question]

SSJ7. My phone consistently, after approximately every 60 seconds makes an alert tone even if theres nothing to alert. This is iritating and not funny at all

 

[B. Diddy]

Welcome to Android Central! Is it the same notification tone as your default one, or does it sound different? Does it persist if you turn off NFC?