Robert H. Withnell

B.Sc., The University of Western Australia (Physics), 1983
M.Sc., Curtin University of Technology (Audiology), 1995
Ph.D., University of Western Australia (Physiology), 1999
Postdoctoral Fellow, Northwestern University

Research Interests

The ear is the only one of our five senses capable of detecting signals embedded in a background of noise (see Hudspeth, 1997). The role 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

Representative Publications

Withnell, R.H. and Lodde, J. (2006). In search of basal distortion product generators. Journal of the Acoustical Society of America, 120: 2116-2123.

Withnell, R.H., Dhar, S., and Thomsen, A. (2005). A comparison of OAEs arising from different generation mechanisms. Hearing Research, 207: 76-86.

Withnell, R.H. and McKinley, S. (2005). Delay-dependence for the origin of the nonlinear derived transient evoked otoacoustic emission. Journal of the Acoustical Society of America, 117: 281-291.

Goodman, S.S., Withnell, R.H., De Boer, E., Lilly, D.J. and Nuttall, A. L. (2004). Cochlear delays measured with amplitude-modulated tone-burst evoked OAEs. Hearing Research, 188:57-69.

Shaffer, L.A., Withnell, R.H., Dhar, S., Lilly, D.J., Goodman, S.S., and Harmon, K.M. (2003). Sources and mechanisms of DPOAE generation: Implications for the prediction of auditory sensitivity. Ear and Hearing, 24: 367-379.

Goodman, S.S., Withnell, R.H. and Shera, C.A. (2003). The origin of SFOAE microstructure in the guinea pig. Hearing Research, 183: 7-17.

Withnell, R.H., Shaffer, L.A., and Talmadge, C.L. (2003). Generation of DPOAEs in the guinea pig. Hearing Research, 178: 106-117.