A method and apparatus for testing tires in a repeatable manner. The means 5 is mounted to the bat and can be manipulated to provide the required play length of the tethering line, which is then effective in repetitive striking of the ball with the bat. A directivity control section alters the directivity characteristics under a telescopic operation so as to mainly pick up sounds coming from a frontal direction with an enhancement which is in accordance with the zoom position signal, thereby outputting an R channel audio signal and an L channel audio signal. A plurality of RF transparent panels are then connected to the horizontal support members so as to form a concealment assembly that conceals the antenna support structure and antennas.