Laryngostroboscopy

the observation of the motion of the true vocal cords by the method of indirect laryngoscopy through the use of intermittent light. Laryngostroboscopy is conducted by means of a special instrument called the laryngostrobo-scope, which permits the frequency of the light pulses to be adjusted to the frequency of vibration of the vocal cords of the person being examined. The adjustment is automatic when an electronic laryngostroboscope is used. If the frequency of the light pulses coincides with the frequency of the vocal cords, the cords appear to be motionless. The vibrations of the vocal cords become visible when the frequency of the light pulses is made unequal to that of the vocal cords. Laryngostroboscopy is used in the determination of functional and organic lesions of the larynx.