A chip thermistor has a pair of outer electrodes opposite each other with a specified distance in between on one of the surfaces of a thermistor element and an inner electrode extending inside the thermistor element so as to overlap these outer electrodes in the direction perpendicular to the surface on which the outer electrodes are formed. A delay is initially set to a predetermined minimum, and an input pulse is transmitted across a transmission line. Then simple averaging or weighted average according to the shift amount is performed on the pixels of the current field and the pixels of the reference field to compensate the current field, thereby being capable of compensating the movement between fields so as to be much smoother than conventional cases. The consumer can listen to and compare multiple demonstration speakers easily and conveniently from the same reference speaker.