Jones, Keith Davies. Letters: Reply to Michael Koller, Austria. Inflated Neck. Brass Bulletin 63 (1988): 81.
A puffed out neck in brass performance is a troublesome condition called, laryngocele. A pouch resulting from a protrusion of the laryngeal mucosa through a weak spot in the thyroid membrane above the laryngeal cartilage (voice box), this condition is usually harmless. It results from high pressure in the larynx and is correctable with a surgical procedure.