An anti-theft device for a motorcycle having an associated remote control, prevents accidental misplacement or accidental confinement of the remote control in a locked storage box on the motorcycle. Two sprockets are connected and secured into one body by arranging the bolt part into a penetration-through hole between adjacent sprockets and by applying methods of stamping and riveting on the bolt part. An extension member extends through each opening in the plurality of balusters to prevent the balusters from rotating about their longitudinal axis. The different segments of the photo sensor sense reflected light and output corresponding sensed voltage signals. The pitch of the lead vocal signal and the user vocal signal are compared and any difference is provided to a pitch shifting module, which then can correct the pitch of the user vocal signal.