You said you can't hear them OR they can't hear you. Is it one OR the other, or does no one hear at all on both ends?I have bought an iphone 4s.. My music plays, games plays audio, my audio and mic works fine on Skype, my siri works fine.. BUT when I call someone or someone calls me I cant hear them or they cant hear me?
Have you tried resetting network settings? Settings>General>reset>Reset Network Settings You will need to add your wifi passcode back in afterward. Not sure if it will work, but worth a try.No one hears at all on both ends.. But its only in calls. In any other game or app such as skype, the sound and mic works fine