The larynx, or “voice box” in colloquial terms, is an organ that began as an air valve to regulate respiration but has evolved in mammals, and particularly humans, for sound production. The human voice is generated by the airflow-driven vibrations of the two vocal folds that reside in the larynx. Under normal circumstances, with the vocal folds in good health, the vibrations are periodic or regular, and the voice produced is smooth and clear. However, the vocal folds can develop problems due to vocal trauma (damage to tissue from voice use), mechanical trauma (damage from surgical instruments or an endotracheal tube), or disease processes that produce growths on the vocal folds. This entry addresses the common vocal fold pathologies and limits the discussion to the ...