Patent ID: 6748092
Filing Date: 2004-06-08
Classification: H04R

Abstract:
A hearing aid having at least one microphone for providing an input signal, at least one signal processing channel receiving and processing at least a portion of said input signal to produce at least one output signal, an output amplifier for amplifying said at least one output signal, and an output transducer responsive to the amplified output signal, said at least one channel including a signal processing circuit for processing said input signal portion in accordance with a percentile estimator output signal, and a percentile estimator for providing said percentile estimator output signal, said percentile estimator comprising:a comparator stage for comparing said input signal portion to said percentile estimator output signal; a first control stage responsive to an output from said comparator stage for providing an integrator control signal representing a value and direction of integration; a multiplier stage for modifying said value of the integrator control signal in accordance with a modification signal to produce a multiplier output signal; a first integrator responsive to said multiplier output signal for providing said percentile estimator output signal; and a second control stage responsive to the integrator control signal of said first control stage for controlling a second integrator to provide said modification signal to the multiplier stage, wherein the second control stage contains a zero-cross-detector stage coupled to the input of said second control stage and adapted for providing a reset signal for resetting said second integrator to a predefined minimum value whenever the output of the first control stage changes.