Effects of Acoustic Overstimulation and the Associated Cellular Lesions on the Cochlear Amplifier: Simulation Results
2014 (English)Manuscript (preprint) (Other academic)
A physiologically-based electromechanical model of the human cochlea is used in this study to explicitly simulate the effects of acoustical overstimulation, and the associated cellular deficiencies, on the gain of the cochlear amplifier. The simulations demonstrate that as the micromechanics of the stereocillia transduction channels is altered due to the traumatic acoustical overstimulation, the compressive/nonlinear behavior of the cochlear amplifier is significantly modified. When the loudness growth is estimated by the integral of the cochlear amplification with respect to the sound intensity, these modifications lead to an impaired loudness function reminiscent of the recruitment phenomenon. Furthermore, when a severe noise-induced loss of outer hair cells is assumed at basal regions of the cochlea, the model predicts a mild loss at lower frequencies followed by a steeply sloping notch-like amplification loss of approximately 80 dB around 4.5 kHz. This prediction is reasonably in line with the threshold elevations observed clinically from the noise-damaged human ears. Moreover, the results quantitatively demonstrate that the center frequency, the width and the depth of the amplification loss are directly determined by the severity and the location of the outer hair cell loss along the cochlear duct.
Place, publisher, year, edition, pages
Otorhinolaryngology Medical Engineering
IdentifiersURN: urn:nbn:se:liu:diva-105808OAI: oai:DiVA.org:liu-105808DiVA: diva2:710708