An assessment of a conical horn waveguide to represent the human eardrum

Taylor N. Fields, Lucia Schnetzer, Eileen Brister, Charles W Yates, Robert Withnell
Publication Date
2018
Website
Publication information

This study examined a model of the acoustic input impedance of the ear that includes a waveguide model of the eardrum. The eardrum was modeled as a lossless conical-horn with rigid walls. The ear canal was modeled as a one-dimensional lossy transmission line. The output impedance of the eardrum, the middle ear, and the cochlea, was modeled as a circuit analog. The model was fit to acoustic input impedance data from human ears using a nonlinear least-squares fit. The impact of a conical-horn shape for the eardrum was quantified by comparison with the eardrum modeled as a near-flat surface. The model provided a good match to the data over the frequency range examined. A conical-horn model of the human eardrum provided gain at high frequencies, most notably above 1–2 kHz, with a broader middle-ear frequency response. This finding may suggest that eardrum shape plays an important role in sound transmission to the cochlea.

Citation

Fields, T. N., Schnetzer, L., Brister, E., Yates, C. W., & Withnell, R. H. (2018). An assessment of a conical horn waveguide to represent the human eardrum. Journal of Physics D: Applied Physics51(18), 185401.