When a point-of-order is called, all - ALL - conversation stops.
It need be said only in a normal voice. All the other board members should hear it, recognize it, and honor it.
If the Chair doesn't hear it, repeat it. If necessary, repeat it more loudly.
If that doesn't work, stand up and say loudly, "Mr. Chair. POINT-OF-ORDER!!!"
The Chair should know what to do next.
If the Chair doesn't, then any board member should hold up a copy of Robert's Rules of Order and offer it to the Chair.
The board needs a Parliamentarian. In more ways than one. The District does not have one or anyone familiar enough with Robert's Rules to serve as one.