Untitled Document

Research

Cynthia G. Fowler

Ph.D., Northwestern University
Professor, Department of Communicative Disorders
cgfowler@wisc.edu
http://www.comdis.wisc.edu/staff/cgfowler/index.php

Hearing in Aging

My research focuses on the central auditory nervous system and its functions in health, in aging, and in disorders of the auditory neural system. Our studies typically develop auditory evoked potential paradigms as correlates of specific behavioral abilities in order to develop a better understanding of the neural processes that underlie behavioral indications of hearing.

One area of research focuses on developing an understanding of the mechanisms behind the increasing difficulty people have in understanding speech as they age. Behavioral studies suggest that underlying problems are associated with the complexity of speech and difficult listening environments. Of particular interest is the relation between hearing and cognition, and their effects on brain plasticity. A number of cortical auditory evoked potentials are used as objective measures of hearing impairment, cognition, and brain plasticity with rehabilitation.

Another area of research concentrates on binaural hearing, which is important for localizing sounds coming from different directions, and for understanding speech in noisy surroundings. We have identified several evoked potential measures that correspond to the ability to localize tonal signals in background noise. We are using these potentials in older people and in people with various types of hearing loss to determine if reduced binaural processing is related to their difficulties in communicating in noisy environments.

Finally we use non-human primates as a model of auditory aging to help us understand the development of auditory aging in humans. Using auditory evoked responses from the cochlea and neural systems, we can determine the type and severity of hearing losses in monkeys, and monitor the rate at which the monkeys develop hearing loss with age. Older monkeys, like older humans, lose hearing in the higher frequency range and have poorer binaural processing. We are assessing the relationships among diet and other physiological functions on developing hearing losses.

Representative Publications
Fowler, C.G., Chiasson, K.B., Hart, D.B., Beasley, T.M., Kemnitz, J., & Weindruch, R. (2008). Tympanometry in rhesus monkeys: effects of aging and caloric restriction. Int. J. Audiol., 47(4), 209-14.

Fowler, C.G., Chaisson, K.B., Brown Hart, D., Kemnitz J., & Weindruch, R. (2007). Tympanometric findings in rhesus monkeys: Effects of aging and caloric restriction. International Journal of Audiology, 47(4), 209-214.

Fowler, C.G., & Leigh-Paffenroth, E. (2007). Hearing. In Encyclopedia of Gerontology (2nd ed.) (pp. 662-671). Kidlington, Oxford, UK: Elsevier Ltd.

Leigh-Paffenroth, E., & Fowler, C.G. (2006). Amplitude modulated auditory steady state responses in younger and older listeners. Journal of the American Academy of Audiology, 17(8), 582-59.

Torre, P., Mattison, J. A., Fowler, C. G., Lane, M. A., Roth, G. S., & Ingram D.K. (2004). Assessment of auditory function in rhesus monkeys (Macaca mulatta): Effects of age and calorie restriction. Neurobiology of Aging, 25(7), 945-54.

Fowler, C.G. (2004). Auditory brainstem response in adults. In R. Kent (Ed.), The MIT Encyclopedia of Communication Disorders (pp. 429-433). Cambridge, MA: The MIT Press.

Fowler, C.G., Bauch, C.D., & Olsen, W.O. (2002). Diagnostic implications of stimulus polarity effects on the auditory brainstem response. Journal of the American Academy of Audiology, 13, 72-82.

Fowler, C.G., Torre, P., & Kemnitz, J.W. (2002). Effects of dietary restriction and aging on the auditory function of rhesus monkeys (Macaca mulatta): The University of Wisconsin Study. Hearing Research, 169, 24-35.

Fowler, C.G., Kile, J., & Hecox, K.E. (2001). Electrical status epilepticus in slow wave sleep: A prospective case study of a cortical hearing impairment. Journal of the American Academy of Audiology, 12, 174-182.

Torre, P., & Fowler, C.G. (2000). Age related changes in auditory function of rhesus monkeys (Macaca mulatta). Hearing Research, 142, 131-140.

Torre, P., Lasky, R.E., & Fowler, C.G. (2000). Aging and middle ear function in rhesus monkeys (Macaca mulatta) Audiology, 39, 300-304.

Callan, D., Lasky, R.E., & Fowler, C.G. (1999). Neural networks applied to retrocochlear diagnosis. Journal of Speech-Language-Hearing Research, 42, 287-289.

Fausti, S.A., Henry, J.A., Helt, W.J., Phillips, D.S., Frey, R.H., Noffsinger, D., Larsen, V.D., & Fowler, C.G. (1999). An individualized, sensitive frequency range for early detection of ototoxicity. Ear and Hearing, 20, 497-505.

Cone-Wesson, B., Ma, E., & Fowler, C. G. (1997). Effect of signal level and frequency on ABR and MLR Binaural interaction in human neonates. Hearing Research, 106, 163-178.

Fowler, C.G., & Mikami, C.M. (1996). Effects of monaural and binaural phase on the middle and late auditory evoked potentials. Journal of the American Academy of Audiology, 7, 23-30.

Blanks, R. H. I., Fowler, C. G., Zizz, C. A., & Williams, K. E. (1996). Postural adjustments produced by moving visual (horizontal optokinetic) patterns. Journal of the American Academy of Audiology, 7, 39-48.

Durrant, J. D., & Fowler, C. G. (1996). ABR protocols for dealing with asymmetric hearing loss. American Journal of Audiology, 5, 5-6.

Fowler, C. G., & Mikami, C. M. (1995). Phase effects in the binaural auditory brainstem response. Journal of the American Academy of Audiology, 6, 399-406.

Want to find more Publications? Click here to search the publication database