It is possible that the sample rate of the Input audio is set too high to be successfully processed.
On the Mac, open the Applications folder, open the Utilities folder, and look for the Audio MIDI Setup. Double click on this, select the Audio Devices tab, and look under Audio Input at the Format. The Format should be set to 44100.0 Hz.
The Built-in Microphone should now work.
Last updated: Jun 16, 2011
