Arrangement of an internal component (not shown) arranged in the vicinity of the top side is different from that of the hinge side of an image element protective screen (2). An actuator (5) is fixed to the top side of the image element protective screen (2) and an actuator (4) is fixed to the hinge side of the image element protective screen (2). Since Arrangement of the internal component in thevicinity of the actuator is different, different sound pressure frequency characteristics or the like are experienced when each actuator is driven independently. When the actuators (4, 5) are driven simultaneously, sound pressure frequency characteristics and vibration frequency characteristics can be flattened. Isolation between the vibration speed of a vibrator near one actuator and the vibration speed of a vibrator in the region near the other actuator that are produced by respective actuators is set at 10 dB or above.