Voice projection is the strength ofspeaking orsinging whereby thehuman voice is used powerfully andclearly. It is a technique employed to command respect and attention, such as when ateacher talks to a class, or simply to be heard clearly, as used by anactor in atheatre or duringdrill.

Breath technique is essential for proper voice projection. Whereas in normaltalking one may use air from the top of thelungs, a properly projected voice uses air properly flowing from the expansion of thediaphragm. In goodvocal technique, well-balanced respiration is especially important to maintaining vocal projection. The goal is to isolate and relax the muscles controlling thevocal folds, so that they are unimpaired bytension. The externalintercostal muscles are used only to enlarge the chest cavity, whilst the counterplay between the diaphragm andabdominal muscles is trained to control airflow.

Stance is also important. Actors are taught to stand erect with the feet shoulder width apart and the upstage foot (foot farther from the audience, when not facing the audience) slightly forward. This improves balance and breathing.

Insinging, voice projection is often equated withacoustic resonance, the concentrated pressure through which one produces a focused sound. True resonance will produce the greatest amount of projection available to a voice by utilizing all the key resonators found in the vocal cavity. As the sound being produced and these resonators find the sameovertones, the sound will begin tospin as it reaches the ideal singer'sformant at about 2800 Hz. The size, shape, and hardness of the resonators all factor into the production of these overtones and ultimately determine the projective capacities of the voice.^[1][2]

• Human microphone, where speech is "amplified" by the audience, repeating the speaker