Jeffery T. Lichtenhan, PhD, Assistant Professor, Otolaryngology—Head & Neck Surgery
Our research addresses questions related to normal and diseased cochlear physiology. Our approach is to understand the origins of objective measurements that can be used in the clinic. If the cell types, spatial location, and contributing mechanisms can be understood, these objective measurements would have better differential diagnostic capabilities for sensorineural hearing loss.
Our research also addresses questions related to low-frequency hearing. Our approach uses a novel objective measure of low-frequency physiology – the Auditory Nerve Overlapped Waveform. As compared to the high-frequency cochlear base, less is known about the low-frequency cochlear apex because, in part, conventional electrophysiologic techniques perform adequately only at high-frequencies above 1 kHz or so. Understanding low-frequency hearing and hearing loss is important because the majority of speech sounds and many bothersome environmental background noises are of low frequency.
Understand the origins cochlear physiology measurements
We have developed an approach to slowly inject nanoliter volumes of pharmaceuticals to manipulate the entire length of the sealed cochlea in a highly predictable manner. We are currently using this approach to understand the origin of objective measurements from the ear. In particular, we are addressing controversies on the spatial origin(s) of reflection-source otoacoustic emissions (e.g., transient evoked, and stimulus frequency otoacoustic emissions).
Understand the origins of low-frequency hearing loss associated with Ménière’s disease
There are many animal models of endolymphatic hydrops, a feature associated with Ménière’s disease. In none of these models has the hallmark attribute of low-frequency sensorineural hearing loss Ménière’s disease been identified. We study low-frequency hearing in animal models of endolymphatic hydrops to gain insight to the origin of low-frequency hearing loss in ears with Ménière’s disease.
The human medial olivocochlear efferent system
At least two putative roles of the medial olivocochlear efferent system is to turn down the gain of the cochlear amplifier to assist with listening in the presence of background noise and to protect against noise-induced hearing loss. Most of what is known about the efferent system was learned from animal models. We aim to translate several experimental paradigms to humans by using non-invasive procedures.
Jeffery T. Lichtenhan, PhD
Carla Valenzuela, MD
Shannon M. Lefler, AuD
NIH/NIDCD R01 DC014997 (Jeffery T. Lichtenhan, PI) 1/16 – 12/20
Origins of physiologic measurements from the ear
Kaf, W.A., Abdelhakiem, M., Zahirsha, Z., Lichtenhan, J.T. (2015). “Ménière’s Disease: Current and Potential New Objective Measures using Electrocochleography” SIG 6 Perspectives on Hearing and Hearing Disorders: Research and Diagnostics. 19, 44-54.
Lichtenhan, J.T., Wilson, U.S., Hancock, K.E., Guinan, J.J. (2016). “Medial Olivocochlear Efferent Reflex Inhibition of Human Cochlear Nerve Responses” Hearing Research. 333:216-24. (13) Wilson, U.S., Kaf, W.A., Danesh, A., Lichtenhan, J.T. (2016). “Assessment of Low-Frequency Hearing with Narrow-Band Chirp Evoked 40-Hz Sinusoidal Auditory Steady State Response” International Journal of Audiology. 55(4):239-47.
Smith, B.S., Lichtenhan, J.T., Cone, B. (2016). “Behavioral pure tone threshold shifts caused by tympanic membrane electrodes” Ear & Hearing. 37(4):e273-5.
Lichtenhan, J.T., Hartsock, J.J., Dornhoffer, J., Donovan, K.M., Salt, A.N. (2016). “Drug delivery into the cochlear apex: Improved control to sequentially affect finely spaced regions along the entire length of the cochlear spiral” Journal of Neuroscience Methods.1;273:201-209.
Lichtenhan, J.T., Hirose, K., Buchman, C.A., Duncan, R.K. Salt, A.N. (2017). “Direct administration of 2-Hydroxypropyl-Beta-Cyclodextrin into guinea pig cochleae: Effects on physiological and histological measurements” PLoS One. 12(4):e0175236.
Smith, B.S., Lichtenhan, J.T., Cone, B. (2017). “Contralateral Inhibition of Click- and Chirp- Evoked Human Compound Action Potentials” Frontiers in Neuroscience. 11, 189.
Wilson, U.S., Sadler, K.M., Hancock, K.E., Guinan, J.J. Jr., Lichtenhan, J.T. (2017). “Efferent inhibition strength is a Physiological Correlate of Hyperacusis in Children with Autism Spectrum Disorder” Journal of Neurophysiology. 118(2):1164-1172.
Lichtenhan, J.T., Lee, C., Wenrich, K.A., Dubaybo, F. Wilson, U.S. (2017). “The Auditory Nerve Overlapped Waveform (ANOW) detects small endolymphatic manipulations that may go undetected by conventional measurements” Frontiers in Neuroscience. 11:405.
Kennedy, A.E., Kaf, W.A, Ferraro, J.A., Delgado, R.E., Lichtenhan, J.T. (2017). “Human summating potential amplitudes vary with tone burst repetition rate and duration” Frontiers in Neuroscience. 11:429.
Pienkowski, M., Adunka, O.F., Lichtenhan, J.T. (2018). Editorial: New Advances in Electrocochleography for Clinical and Basic Investigation. Frontiers in Neuroscience. 12:310.
Spehar, B., Lichtenhan, J.T. (2018). “Patients with normal hearing thresholds but difficulty hearing in noisy environments: A study on the willingness to try auditory training” Otology & Neurotology. 39(8):950-956.