Giving a bell as a wedding gift is another Irish tradition. The chime of bells is said to keep evil spirits away and also remind the married couple of their wedding vows. A nice modern twist is to hand out tiny bells to your guests to ring as you ‘tie the knot’ or when you exit the church instead of throwing confetti.
From Ireland, With Love: Celtic Wedding Traditions Slideshow
Bells were thought to ward off evil spirits and were also used if the married couple had an argument. One of the newlyweds would ring the bell as a way to end the fight and make a truce, reminding them of their wedding vows.