I am using a MacBook Pro now, and I have got an issue with its audio. I am not able to hear any audio at all, fro my MacBook Pro, and therefore I am not able to listen any song or other audios from it. when I pressed the F5 button so as to increase the volume of my MacBook Pro, then just below the volume icon I saw a circle with a line on it. I think that the audio is got disabled in my MacBook Pro. I donít know how it got disabled, but now I really donít have any idea about how to enable it again, therefore I will really need someoneís help for doing this. So, please, help me to enable it again so that I can hear the audio from it.