Middle-ear circuit model parameters based on a population of human ears

Abstract

Middle-ear circuit model parameters are selected to produce overall magnitude and phase agreement with pressure to stapes velocity transfer function measurements made on 16 human temporal bones, up to approximately 12 kHz. The circuit model, which was previously used for the cat, represents the tympanic membrane (TM) as a distributed parameter acoustic transmission line, and ossicular chain and cochlea as a network of lumped circuit elements. For some ears the TM transmission line primarily affects the magnitude of the response, while for others it primarily affects the phase. Model responses also compare favorably with velocity ratio data between the umbo and stapes footplate as well as between the umbo and incus, and exhibit similar characteristics to three previous input impedance measurements, including two from living ears. Similarities are also shown between the model magnitude and adjusted pressure to stapes velocity measurements from living ears, suggesting that the model may suitably approximate the behavior of living ears. In addition to fitting individual measurements, a set of parameters is selected to produce agreement with the mean of the 16 measurements up to 10 kHz, to allow the main features of the ensemble to be reproduced from a single parameter set.