Sony PCG-GR300K VAIO User Manual page 87

To connect an external microphone
 Locate the Microphone jack identified by the
the Microphone jack further distinguishes this jack from other jacks and ports. Plug the microphone cable into the
Microphone jack.
Connecting microphone to microphone jack
Note:
See the manual that came with your microphone for more information on its installation and use.
symbol on the back panel of the notebook. A protruding dot above
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