Barbs007,
We appreciate that additional information. Let’s continue to look into this with you. Next, follow these steps to further test the sound of the receiver of your iPhone:Â
1. Set the Ring/Silent switch to ring.
2. Go to Settings > Accessibility.
3. Tap Audio/Visual.
4. Slide the audio volume balance slider all the way to the right.
5. Go to Settings > Sound & Haptics > Ringtone.
6. Tap on a ringtone to play it.
7. Listen to the sound from the receiver.
When you're done testing, be sure to return the audio volume balance slider to its previous setting under Settings > Accessibility > Audio/Visual.
If the sound from the receiver is muffled when you play a ringtone with those steps, then we would recommend having your device inspected:
iPhone Repair and Service
If the sound from the receiver is fine after doing this, then next make a FaceTime audio call and see if the sound is muffled during this call as well.
Use FaceTime with your iPhone
We hope that helps!