Q: why is there screeching when I make a phone call

I have exactly the same problem with my iphone 4.  It happens with every incomming call but I can hear them clearly

http://support.apple.com/kb/TS2802

I have the same problem, terrible screaching on phone when make or receive calls. Seems to be ok when have phone on loudspeaker. Is this a hardware issue i.e. is it covered by Apples warranty does anyone know. Have reset settings etc but didnt work.

My stepfather had the same issue for his 4S iPhone - To to General - Touch reset network - reset network settings - Now iPhone will reboot.  And then the network settings will go back to default network settings.  His iPhone no longer makes the screeching noise.

I think its the same to reset the network settings as all the other iPhones; but not sure

Asiangem