By focusing on the opening of his sound column backward and downward, the player forgets about his real trunk and his mouth, thus ensuring that his throat remains free of contractions.
The objective for both the pharynx and the larynx is to keep the throat open and supple, avoiding closure by the constrictor muscles. The regulation of the pharynx under the organizing control of the ear consists of achieving what is famous in singing as the open throat with the help of the dilator muscles and the tongue.
Alfred Tomatis, The Ear And The Voice
(translated by Roberta Prada and Pierre Sollier)