H04R21/00 - CPC Classification Index

ClassID:

232039 ⎘

H04R21/00 - CPC Classification

Classification description:

Variable-resistance transducers

Sub-classes:

H04R21/02 » Microphones 18
H04R21/04 » Gramophone pick-ups using a stylus; Recorders using a stylus 0

Recent Application in this class:

20220068254

2022-03-03

Reactive silent speaker device for simulating harmonic nonlinearities of a loudspeaker

20090079298

2009-03-26

Multi-cantilever MEMS sensor, manufacturing method thereof, sound source localization apparatus using the multi-cantilever MEMS sensor, sound source localization method using the sound source localization apparatus