An arrangement is described in which an endoscope 3 inserted into the pharynx of the patient B is used to visually examine the vibrations of the vocal cords 2, while using light that contains little or no infrared light. At the same time, an oscillogram of the vibrations of the vocal cords is plotted, showing the sequence of motion of the vocal cords. The latter purpose is served by an emitter 1, which is attached to the throat of the patient B below the vocal cords 2 and which produces light in the near infrared range (NIR). Using a mirror 5 that reflects infrared light, the light modulated by the vibration of vocal cords is coupled out and fed to a sensor 6, which, together with an evaluating unit 9, detects and evaluates the vocal cord signals.