In the South Tower is the biggest Bell of Notre-Dame known as the "Bourdon". It sounds for the great festivals like Christmas, Easter, Pentecost, or all Saints ' day and at major events like the death of Pope John Paul II and the election of his successor Benedict XVI.
The Bourdon was melted, more than 300 years ago and baptized Emmanuel by his godfather Louis XIV. It weighs 13 tons and its wing, the part inside the Bell that taps against the walls to produce the sound, is 500 kilos.
In the North Tower, four bells ensure the daily ringing of the Cathedral's hours and offices. They weigh between 2 000 and 3 000 kilos each.
The bells by their ringtones punctuated the lives of the faithful, calling for prayer, marking the offices of their solemnity. In the past, they also allowed all inhabitants to know the time; although today everyone has a watch, it continues to spell the time signifying that the Cathedral is a place of life.