| 摘要 |
A hearing device, e.g. a hearing aid, comprises a forward path comprising an input transducer providing an electric input signal, a combination unit, a signal processing unit configured to apply a forward gain to signal of the forward path and to provide a processed electric output signal, a frequency shifting unit for de-correlating the processed electric output signal and the electric input signal, and an output transducer. The hearing device further comprises an adaptive filter for providing an estimate of an external feedback path, and located in the forward path. The feedback estimation unit provides a resulting feedback estimate signal, which is combined with the electric input signal in the combination unit to provide a resulting feedback corrected signal, and a correction unit for influencing said estimate of the feedback path by diminishing a residual bias, being a result of the frequency shift, in said resulting feedback estimate signal. |
| 主权项 |
1. A hearing device, e.g. a hearing aid, comprising
an input transducer for converting an input sound to an electric input signal representing sound, an output transducer for converting a processed electric output signal to an output sound or mechanical vibration, a signal processing unit operationally coupled to the input and output transducers and configured to apply a forward gain to the electric input signal or a signal originating therefrom, and a frequency shifting unit for de-correlating the processed electric output signal and the electric input signal, the input transducer, the signal processing unit, the frequency shifting unit, and the output transducer forming part of a forward path of the hearing device, the hearing device further comprising a feedback cancellation system for reducing a risk of howl due to acoustic or mechanical feedback of an external feedback path from the output transducer to the input transducer, the feedback cancellation system comprising
a feedback estimation unit comprising
a first adaptive filter for providing an estimate of said external feedback path, anda combination unit located in the forward path,
wherein the feedback estimation unit provides a resulting feedback estimate signal, which is combined with the electric input signal or a signal derived therefrom in the combination unit to provide a resulting feedback corrected signal, wherein the feedback estimation unit further comprises
a correction unit for influencing said estimate of the feedback path by diminishing a residual bias in said resulting estimate of the feedback path introduced by the frequency shifting unit. |
