Voice includes the pitch, volume, and quality of the voice. The pitch is determined by the frequency of vocal cord vibrations and is perceived as high or low. The volume of the voice is determined by the strength of the airflow from the lungs, and is perceived as loud or soft. The quality of the voice refers to the unique characteristics that make a person's voice recognizable, such as hoarseness, breathiness, or nasality.
When an individual has a voice disorder, their voice may sound different from typical or expected voice characteristics. Examples of voice disorders include vocal nodules, which are growths on the vocal cords caused by vocal abuse, and spasmodic dysphonia, which is a neurological disorder that causes involuntary spasms of the vocal cords.