However, some iPod models, like the iPod Touch, included a built-in headphone jack that could be used with a headset that has a microphone. This allows for hands-free calling and voice recording.
You may be thinking of a headset like this, which is often used with iPods and other devices:
[Image of a headset with a microphone]
The microphone in these headsets typically looks like a small, round, silver or black capsule, usually located on the wire near the earpiece.