I was a preteen at the end of the Second Vatican Council, which pretty much changed everything about Mass in the United States. I didn’t miss the Latin or the incense. But I was sorry to see the sanctus bells go.
At my parish, the altar boys (and yes, they were always boys then) would ring the little set of four bells just before the consecration. It was a “Pay attention! Something important is happening here” moment even a child could respect. I still feel that way as an adult; in the past year, I’ve been been to a High Traditional Latin Mass twice, and while the “smells” sent me to the lobby coughing, I was still fascinated and moved by the bells.
Most Sundays, the Mass I attend is early and quiet. We don’t sing anything other than the Alleluia (and of course, during Lent we don’t sing or say that). The only smell is the faint odor of wood, or perhaps product used to clean the wood. But last Sunday, we had bells. They weren’t in the hands of the altar boys or the Handbell Choir that’s part of some other Masses. They also didn’t appear to be errant rings from a phone. They rang at random times during the Mass, not just during the consecration. I know I wasn’t the only one to hear them; other people were turning their heads in the direction of the sound as well.
Perhaps some considered this to be noise, a distraction from the usual orderly, peaceful time of worship. For me, it was a little gift from God, a reminder of the magic he can work in this world and in our lives.
The Mass ended, the mystery unsolved.
I wish the bells would come back, too. As a convert, I never experienced them growing up; have experienced them only occasionally as an adult. But I believe they perform an important function, as you say. They are an audibly tangible sign of mystery, which is so central to our faith.