Hi,
Page #17 of the second manual on the following link
http://h10025.www1.hp.com/ewfrf/wc/manualCategory?cc=us&lc=en&product=5273906
says
Produces sound when connected to optional powered stereo speakers, headphones, earbuds, a headset, or television audio. Also connects an optional headset microphone.
It does not support optional microphone only devices. Therefore you can have two options:
(a) Use a headset with build in microphone such as:
(b) Use USB microphone
http://www.ebay.com.au/itm/Behringer-C1U-USB-Condenser-Microphone-Free-Shipping-/271373945255
Regards.
