Asus UL20A User Manual page 11

4
Headphone Output Jack
The stereo headphone jack (1/8 inch) is used to connect
the Notebook PC's audio out signal to amplified speakers
or headphones. Using this jack automatically disables the
built-in speakers.
5
Microphone Input Jack
The mono microphone jack (1/8 inch) can be used to
connect an external microphone or output signals from
audio devices. Using this jack automatically disables the
built-in microphone. Use this feature for video conferencing,
voice narrations, or simple audio recordings.
Notebook PC User Manual 11