When I plug my iPhone headset into my Macbook Air, the operating system recognizes both the headphones and the microphone. As a "side-effect" it disables the internal speaker and microphone.
Is there a way that it only disables the internal mic, but keeps the internal speakers functioning? What I would like to achieve is that the sound coming in from the external mic is played over the internal speakers. LineIn doesn't help me (yet), because the internal speaker gets disabled.