Sharon G. Kujawa, Ph.D.
Associate Professor of Otology and Laryngology
Director, Department of Audiology
Research Area Affiliations
Noise-induced and age-related hearing losses are widespread health problems. They are the most common forms of hearing loss seen in adult patients, often co-existing in the same ears, and they are a primary focus of Dr. Kujawa’s research efforts. Her work seeks to clarify how normal inner ear structures and functions are altered by aging and by noise exposure, how vulnerability to these changes is shaped by an individual’s genetic background, and how these processes can be manipulated pharmacologically to reveal underlying mechanisms or for treatment or prevention.
An area of current focus in Dr. Kujawa’s laboratory is the aging of noise-exposed ears. She has discovered an insidious process that begins acutely after noise, as a loss of communications (synapses) between sensory inner hair cells and cochlear neurons. Loss of the neurons themselves follows slowly, but ultimately reaches the same magnitude. These effects of noise immediately and permanently change the way the ear processes sound information, and they occur even when the exposure produces only temporary changes in hearing thresholds; i.e., for exposures previously thought to be ‘safe’.
Moreover, she has shown that such exposures dramatically accelerate the gradual loss of cochlear synapses and cochlear neurons otherwise seen with aging alone. This work has provided the first clear evidence that noise exposure continues to have damaging effects on the ear and hearing long after the noise has stopped.
Ultimately, noise exposure should be regulated, and its consequences diagnosed and treated, in ways consistent with improved understanding of underlying processes and pathology. Thus, this work informs efforts to develop better clinical tests and to identify effective pharmacologic therapies for these common forms of hearing loss, and should guide hearing conservation efforts aimed at better protecting the public health.
Mutant beta-spectrin 4 causes auditory and motor neuropathies in quivering mice.Parkinson NJ, Olsson CL, Hallows JL, McKee-Johnson J, Keogh BP, Noben-Trauth K, Kujawa SG, Tempel BL. Nat Genet. 2001 Sep;29(1):61-5.
Acceleration of age-related hearing loss by early noise exposure: evidence of a misspent youth. Kujawa SG, Liberman MC. J Neurosci. 2006 Feb 15;26(7):2115-23.
Adding insult to injury: cochlear nerve degeneration after "temporary" noise-induced hearing loss. Kujawa SG, Liberman MC. J Neurosci. 2009 Nov 11;29(45):14077-85. doi: 10.1523/JNEUROSCI.2845-09.2009.
Noise-induced cochlear neuropathy is selective for fibers with low spontaneous rates. Furman AC, Kujawa SG, Liberman MC. J Neurophysiol. 2013 Aug;110(3):577-86. doi: 10.1152/jn.00164.2013. Epub 2013 Apr 17.
Age-related cochlear synaptopathy: an early-onset contributor to auditory functional decline. Sergeyenko Y, Lall K, Liberman MC, Kujawa SG. J Neurosci. 2013 Aug 21;33(34):13686-94. doi: 10.1523/JNEUROSCI.1783-13.2013.