Q: Incoming calls can only be heard through speaker switched on help

Hello dilivi,

I'm sorry to hear you are having these issues with your iPhone. If you are having issues hearing calls throught the receiver on your iPhone and can only hear them on speakerphone, you may find the information and troubleshooting steps outlined in the following article helpful:

If you can't hear a person on a call or voicemail or if the sound quality is poor on iPhone - Apple Support

Regards,

- Brenden