PowerBook 2400c: Omni-directional Microphone

The Technical Information booklet for the PowerBook 2400c reports that the Apple Omni-directional Microphone can be used. How does this work, as we have been unsuccessful in our repeated attempts.

Additionally, attaching something with a higher line voltage, like an audio CD-Rom player, results in the sound coming out of the speaker if the input is too loud.
The Technical Specification sheet that is included with the PowerBook 2400c incorrectly states the PowerBook can use an Apple Omni-directional microphone.

The Technical Specification sheet should state; "the sound-in port requires a line level input". The PowerBook 2400c is not compatible with either the Apple Omni-directional Microphone or the Apple Plaintalk Microphone. Apple does not produce a microphone that can be used with the PowerBook 2400c.
Published Date: Feb 18, 2012