Shape and Shift of the Laryngeal Ventricle During Phonation

Abstract

The shape and shift of the laryngeal ventricle during phonation was studied in profile roentgenographs of 41 young males with normal voice function. None of them was a trained singer.

From a mean of 14 mm at rest position of the vocal folds and during quiet respiration, the laryngeal ventricle was elongated by about 7 mm when the tone frequency was increased to 325 cps. The height of the laryngeal ventricle was increased from about 3 mm at rest position to about 5 mm at 225 cps. On further increase of the tone frequency the height diminished.

During respiration the laryngeal ventricle was generally located at the level of the lower border of the 5th cervical vertebra. During phonation at high pitch the laryngeal ventricle was generally elevated while at low pitch it moved downwards.

The elongation of the laryngeal ventricle was due mainly to a forward movement of the anterior border of the ventricle whereas the distance between the posterior border and the cervical column remained unchanged. It is confirmed that during phonation at increasing pitch the cricoid arch is rotated upwards about the transverse axis through the cricothyroid joints. The thyroid cartilage is moved forwards at the same time as the level of the laryngeal ventricle is raised.