Within the Oracle Room, the machine had two chief defensive mechanisms. It could direct electricity sufficient to stun up to at least three Human-sized individuals simultaneously. It could also operate heating elements concealed within certain of the carving panels that could raise the temperature of the room to lethal levels in very short order. Outside of the Oracle Room, the machine enforced its will through the use of the Instrument of Obedience. The voice of the Oracle was provided by James Doohan. (Star Trek Encyclopedia (4th ed., vol. 2, p. 109) )