One of the main functions of the larynx except that breathing is the production of sound. Voice is produced by air pressure coming from the lungs that affects the vocal cords, causing vibration or shake and their sound production. Then the sound is modified on the parts imposed over the larynx such as the lips, soft palate, tongue and nose, giving him characteristic timbre that makes people differ from each other.
Various diseases can disrupt the quality of sound causing frog. Most often hoarsen sound is due to benign tumors that can be mentioned like polyps, nodes encountered in professional users of voice and cysts of the larynx, while at older ages and especially those who have been regular users of tobacco and alcohol as a cause can be mentioned the larynx cancer.