Sometimes, my Samsung Galaxy S4 phone starts emitting a notification sound at intervals of 10 minutes 24 hours a day, without showing any notifications or without displaying anything connected with the notification sound. I have tried several ways to remedy this irritable inconvenience, such as rebooting the phone, ticking off all notification check-boxes associated with apps, and so on... to no avail. This has happened some six times since I bought my phone some 4 months ago, at times when I change the phone battery. This problem usually lasts a number of days before the problem ends by itself. Has anyone any suggestions how one could remedy this irritable problem?