US Patent 10455312 Acoustic transducer as a near-field magnetic induction coil

Aspects of the present disclosure provide an electro-acoustic transducer that serves as an acoustic transducer and as an NFMI coil. The use of a single coil eliminates the need for a dedicated NFMI coil, thereby reducing design complexity and cost of production. Circuitry is provided to allow selective filtering of acoustic and NFMI signals so the acoustic and NFMI signals may coexist in a frequency-divisional multiplexing fashion on a same electro-acoustic transducer coil.