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*H04R - Electric communication technique---> loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers/deaf-aid sets/public address systems {generating mechanical vibrations in general {b06b}; transducers for measuring particular variables {g01}; transducers in clocks {g04}; producing sounds with frequency not determined by supply frequency {g10k}; transducers in recording or reproducing heads {g11b}; transducers in motors {h02}}
===IP Activity:===