: Swipe down from the top-right corner to open the Control Center and use the vertical volume slider.
If the volume remains too loud even at the lowest setting, check these accessibility and safety features: Adjust the volume on iPhone - Apple Support Iphone 13 Call Sound High Voiceee
: Press the Volume Down button on the left side of the device while the call is active to lower the earpiece or speaker volume. : Swipe down from the top-right corner to
: You can ask Siri to "Turn down the volume" during a call. Additional Settings to Check Iphone 13 Call Sound High Voiceee
To lower or adjust the call volume on your Go to product viewer dialog for this item.