H ELECTRICITY
H04 ELECTRIC COMMUNICATION TECHNIQUE
H04R LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
2201/00 Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
H04R2201/003 Mems transducers or their use