Processing multi-channel audio streams using one or more arrangements of single-channel components. When a user puts on the wristwatch-typed pedometer and performs exercise, the heartbeat signal from the heartbeat detector is received by a wireless heartbeat receiving circuit of a control circuit and transmitted to a data processing unit. A single common axle supports the head end pair of rollers from the carriage, forms a pivot support for the folding shoulder stops, and forms part of an adjustable position support assembly for the headrest. Conductive films are formed on side surfaces of the stack structures via the memory film.