The use of bells is symbolic of the proclamation of the Gospel. Sometimes Orthodox churches and monasteries will combine the use of bells with the striking of a wooden or metal semantron, with the semantron being sounded first, then the bells being rung later. The quieter and simpler sound of the semantron is understood to symbolize the Old Testament prophets, for it is the symbol only of a coming event, whereas the ringing of the bells is spread far into the air symbolizing the annunciation of the Gospel throughout the world.