Half-swallow boom is used for clients with low loudness and air wastage from unilateral vocal fold paralysis, severe bowing of the vocal folds, or falsetto voice. Boone and his colleague McFarlane (Boone, 1977; Boone & McFarlane, 1994) developed the half-swallow boom as one of several voice facilitating techniques. It is believed that the swallow procedure maximizes closure of the larynx. Boom is a single-syllable word composed of voiced sounds that can be produced as air is released from the constricted larynx and the oral opening is minimized; this produces some posterior pressure on the larynx. Head turning may also assist with laryngeal closure.