Patent ID: 8422707

Claim:
A listening device for processing an input sound to an output sound according to a user's needs, the listening device comprising: an input transducer for converting an input sound to an electric input signal; an output transducer for converting a processed electric output signal to an output sound; a forward path being defined between the input transducer and the output transducer and comprising a signal processing unit adapted for processing an SPU-input signal originating from the electric input signal in a time-frequency representation comprising successive time frames each comprising a frequency spectrum of the signal in the time frame in question, the signal processing unit defining an input side and an output side of the forward path and comprising a spectral content modification unit configured to modify values of the signal of one or more regions of the frequency spectrum of a given time frame to provide that the modified values are less correlated to the corresponding time-frequency regions of the input signal than the unmodified output signal thereby providing an improved processed output signal; and a feedback loop from the output side to the input side comprising a feedback path estimation unit for estimating the effect of acoustic feedback from the output transducer to the input transducer, wherein the feedback path estimation unit is adapted to use the improved processed output signal in the estimation, wherein the spectral content modification unit is further configured to base the modification of spectral content of the signal on a model of the human auditory system to provide that the modifications introduced in the improved processed output signal are not perceptible by the user, and the spectral content modification unit is configured to provide that as much noise as possible is inserted in a given signal frame to be output from the output transducer, to achieve maximum uncorrelatedness with a corresponding frequency region of the input signal, under a constraint that the inserted noise be inaudible to the user.