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Indiana University Bloomington

Robert Withnell

Robert Withnell Associate Professor (Hearing Sciences)

Phone: 812 855 9339

Lab Website


B.S. Physics, 1984, The University of Western Australia
M.S. Audiology, 1995, Curtin University
Ph.D. Physiology, 1999, The University of Western Australia
Postdoctoral Fellow, 1999-2000, Auditory Research Laboratory, Northwestern University

Research Interests

The auditory system is capable of detecting signals embedded in thermal (kT) noise (see Hudspeth, 1997). The relative contribution of the outer and middle ear in setting this auditory sensitivity remains unclear, while it seems that the cochlea acts to enhance signal detection by an internal amplification process that is frequency-specific but, as yet, not well understood (see Dallos et al. 2006, Chan & Hudspeth, 2005). Concomitant with this internal amplification process in the cochlea is sound radiating out of the ear, or otoacoustic emissions, that provide a non-invasive window into cochlear mechanical function (e.g., Shera & Guinan, 2007). My research focuses on the biophysics of the mammalian ear, the goal being a better understanding of how the mechanics of the ear set auditory sensitivity. My current investigations include

  • the role the outer and middle ear have in setting in auditory sensitivity
  • the mechanisms of generation of otoacoustic emissions
  • the role hair cell damage plays in Presbycusis
  • cochlear tuning in mammals

Selected Publications

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.