Noise cancellation earphone
AssigneePhitek Systems Limited
InventorsMark Donaldson, Damien Oliver Givernet
Life of this patent
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Abstract
An active noise cancellation earphone (1) has an acoustic path including a cavity (36) and a pipe (20) leading to the auditory canal (40) which are arranged to form an oscillator in use which has the effect of recovering the open loop system phase characteristics at a selected frequency or frequency range. The earphone (1) also has two parts (5,18) which can be adjusted relative to each other to allow the earphone (1) to be comfortably and correctly positioned in use.
Claims18
An earphone for a feedback active noise cancellation system, the earphone comprising a housing having an acoustic outlet adapted to be received in the auditory canal of the ear, a speaker and a microphone provided in the housing anteriorly of the speaker, the speaker and microphone being adapted to be connected to a feedback controller to provide a close-loop active noise cancellation system, the earphone having an acoustic path from the speaker through a pipe to the acoustic outlet such that a Helmholtz resonance occurs between the pipe and the auditory canal at a predetermined frequency over a predetermined frequency range to thereby improve the stability of the closed-loop system.
Dependencies are inferred from the claim text.