| 摘要 |
The invention relates to: A listening system comprising a first input transducer for converting an input sound to an electrical input signal, the electrical input signal comprising a direct part and an acoustic feedback part, an output transducer for converting an electrical output signal to an output sound, a forward path being defined between the input and output transducer and comprising a signal processing unit, a feedback cancellation system for estimating acoustic feedback comprising an adaptive FBC filter arranged in parallel to the forward path, the adaptive FBC filter comprising a variable FBC filter part and an FBC update algorithm part for updating the variable FBC filter part, the FBC update algorithm part comprising first and second FBC algorithm input signals influenced by the electrical input and output signals, respectively, the first and second FBC update algorithm input signal paths comprising first and second variable filters, respectively, the listening system further comprising an electrical update signal essentially consisting of said direct part of said electrical input signal. The invention further relates to a method of improving feedback cancellation and to use of a listening system. The object of the present invention is to provide an alternative scheme for improving acoustic feedback cancellation. The problem is solved in that said first and second variable filters are adapted to be updated on the basis of said electrical update signal. An advantage of the invention is that a desired tone in the input signal is not substantially affected by the feedback cancellation system. The invention may e.g. be used in listening devices comprising active feedback cancellation, e.g. hearing aids, active ear protection devices, etc. |
