Hearing aid comprising an active noise cancellation system
AssigneeOticon A/S
InventorMeng GUO
Life of this patent
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Abstract
Disclosed herein are embodiments of a hearing aid configured to be worn at an ear having an active noise cancellation system configured to cancel or reduce directly propagated sound from said environment to said eardrum of the user. The active noise cancellation system can include an adaptive filter configured to provide a feedforward cancellation signal to compensate the directly propagated sound of an acoustic propagation path from said first input transducer to said second input transducer. Methods of operating a hearing aid are further disclosed.
Claims16
A hearing aid configured to be worn at an ear, at least partially in an ear canal comprising an eardrum, of a user, the hearing aid comprising:
- a first input transducer for converting first sound in an environment around the hearing aid to a first electric input signal representing said sound in said environment;
- a second input transducer for converting sound in said ear canal of the user to a second electric input signal representing said sound in said ear canal;
- a hearing aid processor for processing said first and second electric input signals, or signals depending thereon, and to provide a processed signal based thereon;
- an output transducer for converting said processed signal, or a signal depending thereon, to acoustic stimuli presented to said eardrum of the user;
- an active noise cancellation system configured to cancel or reduce directly propagated sound from said environment to said eardrum of the user, said active noise cancellation system comprising an adaptive filter configured to provide a feedforward cancellation signal to compensate the directly propagated sound of an acoustic propagation path from said first input transducer to said second input transducer, and a combination unit for combining said estimate of the directly propagated sound with said processed signal, the adaptive filter comprising a variable filter and an adaptive algorithm, the adaptive algorithm being configured to provide update filter coefficients to the variable filter in dependence of first and second algorithm input signals,
- wherein said first algorithm input signal comprises said first electric input signal, or a signal dependent thereon, and said second algorithm input signal comprises a combination of said second electric input signal and said processed signal, or a signal or signals depending thereon.
A method of operating a hearing aid configured to be worn at an ear, at least partially in an ear canal comprising an eardrum, of a user, the method comprising:
- providing by a first input transducer a first electric input signal representing sound in an environment around the user;
- providing by a second input transducer a second electric input signal representing sound in said ear canal;
- processing said first and second electric input signals, or signals depending thereon, and providing a processed signal based thereon;
- converting by an output transducer said processed signal, or a signal depending thereon, to acoustic stimuli presented to said eardrum of the user;
- cancelling or reducing directly propagated sound from said environment to said eardrum of the user, by:
- adaptively filtering said first electric input signal, or a signal originating therefrom, thereby providing a feedforward cancellation signal to compensate the directly propagated sound of an acoustic propagation path from said first input transducer to said second input transducer, and
- combining said estimate of the directly propagated sound with said processed signal, and
- providing by an adaptive algorithm update filter coefficients in dependence of first and second algorithm input signals,
- providing said feedforward cancellation signal by said adaptive filtering using said update filter coefficients,
- wherein said first algorithm input signal comprises said first electric input signal, or a signal dependent thereon, and said second algorithm input signal comprises a combination of said second electric input signal and said processed signal, or a signal or signals depending thereon.
Dependencies are inferred from the claim text.