My sister has a 2007 iMac and when she uses FaceTime with me I can hardly hear her. We went thru the settings like sound and hit the input tab, and turned the volume on input all the way up, and the output volume for her side is set about just under 50%. She can not see the blue little squares light up when she talks. Yet if she taps near the camera it is extremely loud. What the heck is going on with her iMac? She is out of warranty and can not use Apple Care to solve this. If she uses Skype there is no problem with sound, I can see and hear her loud and clear. It makes me think there is some setting in the preferences that is blocking her from broadcasting her voice. Again her mic is not muted, but very low in sound , so low in fact it is hard to make out anything that she is saying. Her iMac is about 2 feet or less from her face. But I can chat on my iMac (2009 March) 6 feet away and she hears me fine. So what can this be? Any ideas out there?