Currently Being ModeratedMay 2, 2013 10:04 AM (in response to Colleen2396)
How old is your MacBook Pro, and do you have Applecare? You might still be under warranty.
Otherwise, have you tested your headphones out on another device and tried a different headset on your Mac? Is the channel completely dead, or can you apply slight pressure to the plug to get the channels to work?
Maybe answers to these questions will give clues to others here to help.