Hey everyone, last night I was using my macbook air and the sound changed and was muted and greyed out. I've been looking through past forums and have noticed that others have experienced similar problems. I've reset the PRAM as well as SMC, but still have not had any luck. When I click option on the audio symbol it gives me the option to enter the sound preferences and once I enter it states that there are "no input devices found" as well as "no output devices found." The odd thing is that when I reset/shut down my notebook the startup chime will sometimes sound off, which is strange since I thought the audio might have been completely messed up. If anyone can help it'd be greatly appreciated thanks!