The most important question for anyone born in London is 'Are you a Cockney?' Only those born within the sound of Bow bells can truthfully answer the question with a resounding 'yes.' 'Cockney' is a term of pride in the heart of the East End, an area recently made internationally famous to a new audience due to the global success of the TV series 'Call the Midwife,' set in Poplar. Here we use simple physics to determine the greatest distance that you can be born and still hear the peal of the bells. As such, it should appeal to all those teaching the physics of waves, or sound, in the Greater London area--and beyond.