A rostrum (Greek βῆμα/bêma; Latin plural rostra,) is an elevated podium, a pulpit (early Christian ámbōn, Lat. ambo), or a type of stand, shaped in a variety of forms, which raises the speaker above his audience. This is useful not only from an acoustic point of view, but also lends importance to the protagonist acting on the podium, as it 'lifts' him in a significant way over his surroundings.
Rostrum-like devices must already have been present in the archaic Greek citizen communities, as in all larger communities of colonists which had to decide by consensus (polis). Yet…