How is voice produced?
The vocal folds (vocal cords) are attached within the larynx to the largest of the laryngeal cartilages known as the thyroid cartilage or "Adam's apple". The vocal folds produce sound when they come together and then vibrate as air passes through them during exhalation of air from the lungs. This vibration produces the sound wave for your voice.
In order for the sound to be clear and not raspy or hoarse, the vocal folds must vibrate together symmetrically and regularly. The rate of vibration determines the pitch of the voice. When the voice is hoarse, the vocal folds may not be closing fully, or may not be vibrating symmetrically.