I recently had my 2011 MBP repaired at an Apple Store. Tonight, as I was watching a movie in iTunes on headphones I started hearing odd, loud beeps and what sounded like someone blowing into a mic. It came and went several times, regardless of whether or not the movie was playing, with one occasion sounding reminiscent of the "robot" ringtone on the iPhone. Is it possible I was picking up RF transmissions from nearby? I do live in a relatively densely-populated district. If so, is this expected behaviour with certain types of transmission or is it likely that the recent repair was botched somehow, perhaps disabling some RF-rejecting component(s)? Or is it the headphones? Very interested to get advice on this.