Patent ID: 6097823
Filing Date: 2000-08-01
Classification: G10K,H04R

Abstract:
A digital hearing aid comprising:a microphone operable to receive an input sound signal and to generate a digital input signal in response;a control and modeling circuitry operable to filter and amplify the digital input signal and to perform feedback neutralization and feedback path modeling to generate a digital output signal, said control and modeling circuitry includinga first summing junction operable to subtract an output sound signal feedback component from the digital input signal to generate a feedback neutralized input signal,an amplifier and shaping filter operable to filter and amplify the feedback neutralized input signal and to generate a generated output signal in response,a modeling signal generator operable to generate a modeling signal,a second summing junction operable to combine the generated output signal with the modeling signal to generate the digital output signal,a feedback path modeling adaptive filter operable to receive the modeling signal and a modeling error signal and to filter the modeling signal to generate an output signal,a signal discrimination circuitry operable to receive the feedback neutralized input signal and to generate a modified modeling signal,a third summing junction operable to subtract the output signal from the modified modeling signal to generate the modeling error signal which is provided to an adaptive algorithm used by the feedback path modeling adaptive filter, anda feedback neutralization filter operable to receive the generated output signal and to generate a signal containing the output sound signal feedback component that is provided to the first summing junction, and wherein the adaptive algorithm used by the feedback path modeling adaptive filter is operable to calculate filter taps of the feedback path modeling adaptive filter to minimize the mean-square value of the modeling error signal, and the filter taps are provided to the feedback neutralization filter and used by the feedback neutralization filter to generate the signal containing the output sound signal feedback component; anda receiver operable, receive the digital output signal and to generate an output sound signal in response.