|MadSci Network: Anatomy|
Martin, The vocal cords are actually ligaments connected to the vocal process of each arytenoid cartilage in the back and to the thyroid cartilage in the front. The vocal processes of the arytenoids are manipulated by the vocal and cricoarytenoid muscles (lateral and posterior). The vocal cords are brought together and separated by flexing these muscles. When the vocal cords are brought together, their tension is controlled by the vocal muscles and the cricothyroid muscles so that the air passed through them causes the cords to vibrate. When relaxed, the vocal cords vibrate slower than when tensed, causing a lower pitch. As for the tensile strength of the chords I have not been able to find that answer. However, I am sure that this varies from person to person because of how their voice pitch changes. For human ligaments, the tensile strength varies between 50 and 100 MPa. As for the loudness of a presons voice depends on how they have "trained" their voice. By increasing the flow and force of expiration through the vocal folds and cords will cause the person to speak softly or loudly. Hope this answers your question. If I find out the exact average I will post it. Mike
Try the links in the MadSci Library for more information on Anatomy.