The secret static on your Skype call
A less obvious bit of artificial sound that you probably hear every day is called comfort noise. Lots of modern telephone systems as well as software like Skype employ noise reduction techniques. Unfortunately, that can result in total silence at quiet points in a conversation and leave you wondering if the call has stopped entirely.
That’s where comfort noise comes in. To fill those lulls, the software adds artificial noise at a barely audible volume. While you won’t consciously notice it, it prevents you from feeling like you’re talking into a void.
Comfort noise isn’t a new concept either. During the siege of Leningrad, the Soviets broadcast the beat of a metronome to reassure citizens that the radio network was still up and running. Radio stations today add comfort noise to broadcasts during quiet periods such as the minute’s silence on Remembrance Day.