Department of Speech, Language and Hearing Sciences

• Middle and inner ear auditory physiology
• Signal processing in the auditory system
• Mechanics of the ear

My research focuses on the biophysics of the mammalian ear, with the goal being a better understanding of how the ear works. My current investigations include the mechanics of:

1. the cochlear amplifier
2. middle ear ossicle motion
3. post middle-ear surgical reconstruction

The study of the cochlear amplifier is focused on examining cochlear gain versus nonlinearity, in collaboration with Drs. Kevin Ohlemiller and Laura Hurley. The study of middle ear ossicle motion includes imaging studies using micro-CT x-rays at Argonne National Laboratory in Chicago, in collaboration with Dr. Claus-Peter Richter. The study of post middle-ear surgical reconstruction is in collaboration with Dr. Charles Yates. My teaching focuses on developing critical thinking skills with an emphasis on problem-solving. My goal in the classroom is student-driven learning and encouraging student engagement. The same is true for mentoring students conducting research. I have taught a variety of courses at the undergraduate and graduate level, including graduate courses in audiology and speech-language pathology programs.

Withnell, R.H., Ohlemiller, K.K. (2018) "Quantifying Cochlear Amplifier Gain Using A Model-Based Evaluation Of DPOAE I/O Functions In Mammals" In Mechanics of Hearing, Bergevin C, Puria S (eds). American Institute of Physics, Melville, NY, in press.

Ueberfuhr, M.A., Fehlberg, H., Goodman, S.S., Withnell, R.H. (2016) “A DPOAE assessment of outer hair cell integrity in ears with age-related hearing loss”, Hearing Research, 332:137-150.

Withnell, R.H., Fields, T.N. (2015) "Zwislocki's model of the middle ear revisited" In Mechanics of Hearing: Protein to Perception, Karavitaki KD, Corey DP (eds). American Institute of Physics, Melville, NY, pp. 060012-1 to 060012-5.

Withnell, R.H., Jeng, P.S., Shofner, W.P., Allen, J.B. (2010) In-situ calibrated sounds and hearing sensitivity. Proceedings of Meetings on Acoustics, Vol 9(1), 10 pages.

Withnell, R.H., Parent, P., Jeng, P.S., Allen, J.B. (2009) Using wideband reflectance to measure the impedance of the middle ear. Hearing Journal, 62, 36-39.

Withnell, R.H., Jeng, P.S, Waldvogel, K., Morgenstein, K., Allen, J.B. (2009) An in-situ calibration for hearing thresholds. Journal of the Acoustical Society of America, 125, 1605-1611.

Withnell, R.H., Hazlewood, C., Knowlton, A. (2008) Reconciling the origin of the TEOAE in humans. Journal of the Acoustical Society of America 123: 212-221.