Strange.
This is what my Parish Priest told us when I was very young, and explained about the bells:
Sometime during the Middle Ages, the Altar and the Assembly was seperated by a divider. It was believed in those times that the Mass was so Sacred that it could not be heard by the Assembly. So, the Priest said everything so softly that even the Altar Server couldn’t hear it. So, in order to inform the Assembly that the Consecration was taking place, the bells were run so people would look up from their prayers, and the Priest would raise the Host above the divider for people to see.
Now that the Consecration is viewed by everyone, the bells are no longer necessary. In my Parish, we haven’t had the bells rung during Consecration for almost 20 years.
We still do have our hand bells, and is used only during the singing of the “Gloria”.