Considered strictly in its bearing on tone-production, the resonance of the mouth- pharynx cavity does not receive much attention from theoretical observers of the voice.

Every vocal tone, good or bad, is produced by the motion of the vocal cords and reinforced by the resonance of the mouth- pharynx cavity.

In the voice the exciting cause of the air vibrations is located at the back of the resonator,-themouth-pharynxcavity.