I noticed that my macbook air produces a sudden beep quite often when i watch youtube movies or just now when I am typing this message. I have no idea where it comes from. It has no specific interval it is just randomly It does remind me to an memory issue. To check it I did an extended memory test with the apple hard where test which came with the install usb stick. Without result, everything if fine according to the test Anyone has another idea where to check or what it can be before i go back to the apple store...?!