Abstract: Embodiments for characterizing ear canal acoustic impedance and reflectance by pole-zero fitting are disclosed. Embodiments include transmitting an acoustic signal into an ear canal by a transducer having an acoustic source pressure. Further embodiments, measure complex cavity pressure, P(f), response based on the transmitted acoustic signal reflected by eardrum using an acoustic measurement device. Additional, such embodiments, calculate complex acoustic reflectance (CAR) based on the P(f). Other embodiments determine number of poles and zeroes of CAR pole-zero model to reduce residual error between the CAR pole-zero model and CAR data stored in memory within a threshold. Also, embodiments verify the residual error of CAR pole-zero model compared to the CAR data is within the threshold. Further, embodiments factor the CAR pole-zero model into an all pass component and a minimum phase component. Additional embodiments determine ear drum impedance by removing the all phase component of the CAR pole-zero model.

Abstract: Method and system for automatically adjusting a hearing aid. The method includes measuring an acoustic reflectance associated with an ear canal as a function of an incident pressure and an acoustic frequency, processing information associated with the measured acoustic reflectance, determining a reflectance slope based on, at least, information associated with the measured acoustic reflectance, and adjusting, at least, one parameter associated with the hearing aid based on, at least, information associated with the reflectance slope. The reflectance slope is associated with a reflectance component varying with the incident pressure.