Q: The Apple earbuds mic is recognized by the Mac, but doesn't work.

Hello there, iTV.

The following Knowledge Base article offers up some great pointers on how to use your Apple Earphones with your mac:

How to use Apple Earphones with Remote and Mic with your Mac

http://support.apple.com/kb/HT3554

Is there a way to tell that my system can use the external microphone?

 

Yes.  From the Apple () menu, choose System Preferences.  From the View menu, choose Sound.   If there is an "External microphone" listed in the Input tab, your computer can use the microphone included with Apple Earphones with Remote and Mic.

Thanks for reaching out to Apple Support Communities.

Cheers,

Pedro.