Ashley47,
First, try resetting your PMU: Shut down your Macbook Pro, disconnect the magsafe adapter, and remove the battery. Press and hold the power button for
at least 5 seconds.
Now, put the battery back in and connect the magsafe adapter (if you like). Start your Macbook Pro normally. If this doesn't fix the problem, there may be a problem with the audio port. This can sometimes be corrected by plugging in a pair of headphones, then unplugging them. Otherwise, you might want Apple to have a look.
Scott