Low volume on call

Hello there Dschulen,

Welcome to Apple Support Communities. This article can help you with trouble hearing on phone calls: If you hear no sound or distorted sound from your iPhone, iPad, or iPod touch speaker - Apple Support

1. "Remove all screen protectors, films, or cases from your device. 
2. Check the speaker opening to see if it's blocked or dirty. On iPhone only, make sure that the receiver isn't blocked or dirty. 
3. If necessary, clean the speaker or receiver opening with a small, soft-bristled brush. Make sure that the brush is clean and dry.
4. Go to Settings > Sounds (or Settings > Sounds & Haptics), and drag the Ringer and Alerts slider back and forth a few times. If you don't hear any sound, or if your speaker button on the Ringer and Alerts slider is dimmed, your speaker might need service.
5. If you hear sound, try making a call with your iPhone and turn on speakerphone. On iPad or iPod touch, make a FaceTime call. If you still can't hear, or hear static or crackling, then your network or reception could be the issue. Try to call again later, or from a different location."

Should this issue persist, get in touch with Apple Support for additional assistance:

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We hope this helps you.

I am having the same issue...very low call volume on iPhone 11 Pro Max. It seems to be related to the iOS 16.0.2 update. I was not having the issue before this update. I have tried every suggestion for a fix. Is Apple planning to release a patch to rectify?