Altar bells draw the congregation’s attention to the Eucharist’ salient points. This was particularly critical during Medieval Latin masses, as the communicants were unfamiliar with the language. Ritual Notes states that bells should be rung on four occasions. The first is at the Sanctus (i.e., “Holy (ring), Holy (ring), Holy (ring) Lord God of Hosts”...) which has given the name, “sanctus bells”, to altar bells. The bells are rung again immediately prior to the Words of Institution (“For in the night in which he was betrayed...”). In Catholic tradition, this is when the elements are about to be become Christ’s body and blood, and the communicants’ attention should be maximized. Thirdly, the bells are rung thrice after each segment of the Words of Institution so the communicants could worship Christ’s elevated presence (the priest genuflects [ring], elevates the consecrated host [ring], and genuflects [ring]). The bells are rung a final time at the Great AMEN inviting the congregation to come forward for Communion. In England, tower bells are often rung simultaneously with the altar bells so that home-bound parishioners could worship with the congregation, and bells are continuously rung during the Gloria at Christmas’ midnight mass.
~Dr. Gil Haas