In perusing varying sources I have not reached a definitive answer on the ability to use a product such as the Headset Buddy on my MacBook Air.
Apple states...
Support for Apple iPhone headset with remote and microphone
...on their web site which led me to believe, along with varying comments that the audio jack is indeed both input/output. Having said that, I did purchase the above Headset Buddy and am unable to get it working in any way. It appears that the OS does not recognize the device in any way and it is not an available selection within Sound, only the internal components.
I want to avoid using a USB solution at all costs but more importantly identify if the port is indeed audio in/out and how I can get my Headset Buddy functioning properly?