Stress - a sound or syllable which is stressed is one upon which there is expended in the articulation relatively great breath effort and muscular energy: in voiced sounds, greater amplitude of vibration of the vocal folds, together with the reinforcing resonation of the supraglottal cavities, results in the physical terms in relatively great intensity of the sound or syllable, such intensity being perceived by the listener as greater loudness associated with the sound or syllable. (Gimson, 1980:222)