Hello ChahitJ07,
Thanks for reaching out to the Apple Support Communities! We understand you are experiencing an issue with your iPhone making an alert sound but you aren't getting any phone calls or alarms going off when this happens. We are happy to help take a look in to this with you.
Just to confirm, when this ringing happens, are there any sort of alerts or indicators on the screen that might display when this starts to happen? You can check the notification center after the ringing happens to see if there might be a notification displaying in relation to what this is:
Use notifications on your iPhone, iPad, and iPod touch
If there aren't any notifications showing, we'd like to ask a few additional questions to get a better understanding.
- When did you first notice this behavior start? Was it after any sort of change, update, or new app download to your iPhone?
- What is the iOS version on your iPhone if you check in Settings > General > About?
- Does your iPhone have any physical or liquid damage done to it that you are aware of?
Keep us updated on how it goes or if you have any questions. We hope this information helps.
Best Regards.