Hello Eric, Well, the Ti was the first Apple computer to not accept their previously standard extended plug. That's the reason I went the USB route and purchased a Telex M - 560 desktop microphone. By the way, it's absolutely unbelievable. Also, this microphone shows up separately as a USB mic in the "input" sound control preference panel. I hope this helps a little. Norm Eric Forat wrote: > > I've been trying to connect a headset and mike to my Ti and the mike > doesn't work. And I tested it with three mikes and nothing. I did > select sys prefs/ sound/ input/ line in, but nothing happens. The > built-in is fine, but I need a unidirectional mike close to my mouth > so I don't have to shout. Is that micro-jack in the back, between the > phone jack and the video out, really a line in ? Or must I go to a > USB model? Any ideas? > Best, eric