| CPC H04R 1/2849 (2013.01) [H04R 1/021 (2013.01); H04R 1/26 (2013.01); H04R 1/2803 (2013.01); H04R 1/2811 (2013.01); H04R 1/288 (2013.01); H04R 2201/029 (2013.01)] | 18 Claims |

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1. An earphone device comprising:
an earphone comprising a speaker cone and a voice coil assembly coupled to the speaker cone;
a sealed enclosure, wherein a front side of the speaker cone is disposed outside the sealed enclosure and a back side of the speaker cone is disposed inside the sealed enclosure, wherein sealed enclosure is configured to maintain a gas pressure level inside the sealed enclosure which is lower than an ambient air pressure level outside the sealed enclosure; and
a control system configured to generate a position control signal and apply the position control signal to a voice coil of the voice coil assembly;
wherein the position control signal is configured to generate an electromagnetic force that is sufficient to move the voice coil to a target null position, while allowing the voice coil to move back and forth about the null position in response to an audio signal applied to the voice coil during operation of the earphone.
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