Hi Diamondsrb,
Welcome to the Apple (user-to-user) Community.
You may need to back-up your data, use strong wi-fi, & update your iPhone to the latest iOS :
Update your iPhone or iPad - Apple Support
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If you have already updated to iOS 16 ... and phone doesn't ring, the info. below may help.
You may have accidentally turned on "Do Not Disturb"
or forgot to turn it off.
NB:
When you have Do Not Disturb turned on, a crescent moon icon
appears in the status bar and on your Lock Screen.
If it is the "Do Not Disturb" setting
Go to Settings > Focus.
Tap Do Not Disturb.
Under Turn on Automatically, set Do Not Disturb to turn on automatically at a certain time, location, or while using a certain app.
Tap the time-setting to turn it off.
Apple support's article: Use Do Not Disturb with Focus on your iPhone or iPad - Apple Support
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Make sure you are using ringtones that you can hear ok.
how to change the sound that plays when you get a call.
Go to Settings > Sounds & Haptics.
Tap Ringtone
Tap a ringtone or alert tone to hear it and set it as the new sound.
(make sure it is not set to "None".)
Apple support's article: Use tones and ringtones with your iPhone or iPad - Apple Support
NB: You can also set different ring tones for the people listed in your "Contacts" if you wish
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If it was not the "Do Not Disturb" setting, and Ringtones were set ok:
Perhaps you may have accidentally "muted" Phone Calls:
Apple support's article: While on a call on iPhone – Apple Support can help with that:
Eg: says:
"Adjust the audio during a call
To change the volume, press the volume buttons on the side of iPhone.
Or swipe down on the call banner, then
Mute: Tap the mute button if it is on mute.
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Hope something here above helps you hear phone calls ok again.
Else:
You might want to reach out to the iPhone Support Team:
There's a "Get Support" link at the bottom of their website (link below),
iPhone - Official Apple Support
All the best :-)