| CPC H04R 1/1041 (2013.01) [G10K 11/17825 (2018.01); G10K 11/17827 (2018.01); H04R 1/1016 (2013.01); H04R 1/1025 (2013.01); H04R 1/1075 (2013.01); H04R 3/06 (2013.01); H04R 7/04 (2013.01); H04R 7/18 (2013.01); H04R 19/00 (2013.01); H04R 19/02 (2013.01); H04R 29/001 (2013.01); G10K 2210/3026 (2013.01); H04R 3/007 (2013.01); H04R 2430/01 (2013.01)] | 20 Claims |

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1. A method for controlling operation of an electrostatic acoustic device including a membrane and an electrode disposed proximate to the membrane, wherein the membrane is configured to respond mechanically to a varying electric field emanating from the electrode when a varying audio signal voltage is applied to the electrode, the method comprising:
injecting a probe signal varying at radio frequency into an input of the electrostatic acoustic device;
detecting a current or charge signal by converting the current or charge signal to a modulated voltage signal, wherein the current or charge signal includes an audio signal varying at audio frequencies modulating the radio frequency of the probe signal;
demodulating the modulated voltage signal to produce an audio output signal varying at audio frequency;
transforming the audio output signal to produce an error signal; and
responsive to the error signal, inputting a control signal to the electrostatic acoustic device, wherein phase and amplitude of the control signal are configured to cancel at least in part a mechanical response of the membrane due to ambient noise.
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