: 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
when voices sound too loud, you must use the physical side buttons . Adjusting the volume from the Home screen often only changes the ringer or media volume, not the in-call speaker. Immediate Solutions During a Call : Swipe down from the top-right corner to
To lower or adjust the call volume on your Go to product viewer dialog for this item. Immediate Solutions During a Call To lower or
: Press the Volume Down button on the left side of the device while the call is active to lower the earpiece or speaker volume.