Controlled exploration of the effects of conductive hearing loss on wideband acoustic immittance in human cadaveric preparations

We focus on determining whether power reflectance (PR), a derivative of WAI, is a possible solution to this problem. PR is a measure of the fraction of sound power reflected from the middle ear when a sound stimulus is presented to the ear canal. PR and other metrics of middle-ear performance (such as ossicular motion via laser Doppler vibrometry) were measured in well-controlled human temporal bone preparations with simulated pathologies. We report measurements before and after simulation of stapes fixation (n = 8), malleus fixation (n = 10), ossicular disarticulation (n = 10), and superior canal dehiscence (n = 8). Our results are consistent with the small set of previously published reflectance measurements made in temporal bones and patients. In this present study, these temporal bone experiments with different middle- and inner-ear pathologies were compared to the initial normal state by analyzing both WAI and ossicular motion, demonstrating that WAI can be a valuable tool in the diagnosis of conductive hearing loss.