Calculation of transfer function of acoustic feedback path for in-the-ear hearing aids with a correction for specific acoustic impedance of a tubule

The formulation of the feedback transmission function of in-the-ear (ITE) with an equivalent circuit model based on the acoustic feedback was examined. The acoustic feedback transmission function of ITE hearing aids was modeled using a transmission matrix. The proposed calculation model can accurately simulate the acoustic characteristics of the feedback path between the ear cavity and the emission area. The validity of the proposed method for estimating the leakage of human ears will be examined by comparing the the calculation and measurement results using human ears. The results show that the proposed calculation method with the correction is useful for analyzing the aids since they usually have severe feedback problems from 1 Hz to 4 kHz.