2The walls, moreover, at half their height, are to have cornices run round them of wood or plaster. For if such be not provided, the voices of the disputants meeting with no check in their ascent, will not be intelligible to the audience. But when the walls are encircled round with cornices, the voice, being thereby impeded, will reach the ear before its ascent and dissipation in the air.
2Further, the inside walls should be girdled, at a point halfway up their height, with coronae made of woodwork or of stucco. Without these, the voice of men engaged in discussion there will be carried up to the height above, and so be unintelligible to their listeners. But when the walls are girdled with coronae, the voice from below, being detained before rising and becoming lost in the air, will be intelligible to the ear.