I have a Late 2009 MacBook. It only has a single audio port. As far as I can tell, it can only be set to be audio out or audio in, not both. So, it is possible to use a non-USB headset with this MacBook? I know there are some newer headsets that only have a single connection for both the mic and headphones. Would this type of headset work on this MacBook? Any help would be greatly appreciated.