A metronome for use by a musician or group of musicians generally includes a signal generator for producing an electrical signal according to a desired timing scheme and one or more transducers in wireless communication with the signal generator. Each transducer, which may take the form of a piezoelectric...http://www.google.com/patents/US7390955?utm_source=gb-gplus-sharePatent US7390955 - Metronome with wireless transducer
