Repeating notification on phone

Since a few weeks I have been getting constant notification alarms on my phone (Sony Xperia XZ Premium). It's extremely annoying. Does not show what the notifications are for. I turned off apps and notifications but alarms keep coming back. Anyone got any ideas what it could be and how to get rid of it.

Welcome to Android Central! I'm not sure if this option is on Sony phones, but go to Settings>Accessibility and look for a Notification Reminder option.

If that isn't present, then try turning off NFC, in case this is the NFC alert tone.