These cartilages are connected to other structures of the head and neck through the extrinsic muscles. The intrinsic muscles of the larynx alter the position, shape and tension of the vocal folds. The vocal cords are finely tuned neuromuscular units that adjust pitch and tone by altering their position and tension. Air Pressure develops below vocal cords due to air from lungs during exhalation.
Vocal cords separate briefly with the release of air.
The following diagram illustrates the vocal cord vibration cycle that occurs 200-400 times a second during sound production. The rapid opening and closing of the vocal cords occur in a vibratory pattern and is responsible for sound production. Thus any structural, inflammatory, or neoplastic lesion of the vocal cord affects voice production and quality. For more information on larynx examination, please see Diagnostic Services .