Larynx: action of lateral cricoarytenoid muscle (English)

The lateral cricoarytenoid is a bilateral muscle attaching between the cricoid and arytenoid cartilages. When these muscles contract, they rotate the arytenoid cartilages medially which brings the tips of the vocal processes together. This results in adduction of the vocal folds and closure of the anterior part of the rima glottidis. The relaxed arytenoid muscles still allow air to pass via the posterior (intercartilaginous) part of the rima glottidis, therefore allowing a toneless sound to be produced i.e. a whisper.