In dramatic performances, the voice is sometimes varied during speech to create variety. While on stage, a performer is able to soften his voice and make it lower. He is also able to make it higher, louder or faster. This speaking technique is used to display a character's changing emotions while keeping the audience's interest. A monotone voice would be counterproductive in capturing the audience. The voice is also varied in theater performances to ensure that it is adequately heard from the stage.
Actors will typically breathe from their abdomen area when performing. This helps to ensure that their voices are loud enough to be heard throughout the audience. Speaking from the abdomen also aids in the relief of tension and performance anxiety. Since actors want to make sure that their speech is enunciated clearly, speaking from the abdomen rather than the throat contributes to the voice's power and presence.
Theater performers will typically speak in what is sometimes referred to as an "outside voice." In other words, the volume they use will almost resemble that of shouting. Even though they must speak with a louder than normal voice, it does not come across as yelling from the audience's standpoint. Typically during rehearsals, stage actors will be coached by directors to ensure that their voices are carrying throughout the theater.
Actors often employ the technique of speaking fully and clearly, rather than mumbling. During the delivery of their lines, they make sure to pronounce each syllable so the entire word is heard. If they want to display a certain emotion that their character is feeling, they may change the pitch of their voice. Adding emotional expression to the voice is a way to convey the character to those audience members who may not be able to clearly see facial expressions from the stage. Usually a performer will make sure that his vocal rate is at the correct speed. He may slow it down in order for his voice to carry and be understood.