Abnormal changes in the voice are called hoarseness. When hoarse, the voice may sound breathy, raspy, strained, or show changes in volume or pitch (depending on how high or how low the voice is). Voice changes are related to disorders in the sound-producing parts (vocal folds) of the voice box (larynx). While breathing, the vocal folds remain apart. When speaking or singing, they come together and, as air leaves the lungs, they vibrate, producing sound. Swelling or lumps on the vocal folds hinder vibration, altering voice quality, volume, and pitch. Laryngoscopy may be suggested by the otolaryngologist at any time during an evaluation for hoarseness. Doctors usually look at the vocal folds either with a mirror placed in the back of the throat, or with a very small, lighted flexible tube (fiber-optic scope) that is passed through the nose to view the vocal folds. The treatment of hoarseness depends on the cause. Many common causes of hoarseness can be treated simply by resting the voice or modifying how it is used.