Silent orders of monks - notably Cistercians and Carthusians, got in there long before the Quakers. (The difference being that the main time the Silent Orders break their silence is in church, while the only time some Friends hold their tongues is in Meeting.)

Maybe there could be a CD put out some time as an enumenical gesture. One side would be a Carthusian or Cistercian silence, and the other would be a Quaker silence.