Chongman, i'm pretty sure that there is a built-in mic, but that port is used for a headset microphone accessory, which would be more convienient, but you would have to buy it. That way, there is a microphone so all systems could take advantage of microphone use in games, but if you really want to take advantage of the feature you'll have to buy the headset rather than put your face right up to the system and talk.