Patent ID: 8351632
Filing Date: 2013-01-08
Classification: H04M,H04R

Abstract:
1. A microphone system comprising: a base; a first microphone apparatus coupled to the base, the first microphone apparatus capable of producing a first output signal having a noise component, the first microphone apparatus having a first variable capacitor formed on a substrate, the first variable capacitor and substrate defining a first back-side cavity; a second microphone apparatus coupled to the base, the second microphone apparatus capable of producing a second output signal, the second microphone apparatus having a second variable capacitor formed on a substrate, the second variable capacitor and substrate defining a second back-side cavity, the first and second back-side cavities being fluidly unconnected; and combining logic operatively coupled with the first microphone apparatus and the second microphone apparatus, the combining logic using the second output signal to remove at least a portion of the noise component from the first output signal, the first microphone apparatus comprising a first microphone with a first low frequency cutoff, the second microphone apparatus comprising a second microphone with a second low frequency cutoff, the second low frequency cut-off being greater than the first low frequency cut-off, the first microphone having a first diaphragm and a first circumferential gap defined at least in part by the first diaphragm, the second microphone having a second diaphragm and a second circumferential gap defined at least in part by the second diaphragm, the second circumferential gap being greater than the first circumferential gap.