presence of otoacoustic emissions in individuals with h.i.
Allison M. Scott
ascott at mail.coin.missouri.edu
Tue Sep 19 16:46:03 EST 1995
I recently read an article in "European Archives of Otolaryngology", Vol.
250. pgs 366-368 which is of great interest. A 6-year-old boy with
unilateral deafness was found to have otoacoustic emissions in his deaf
ear. A full test battery showed a flat ABR, Neg ENG results, Neg CT
scan, and a normal neurologic work-up. Upon electrostimulation of the
auditory nerve, the young boy consistently reported a hearing sensation.
The authors of this study determined that there was a large enough
population of OHCs to cause an OAE, and an IHC disorder is to be expected
due to electrostimulation results.
Another interesting article can be found in "Journal of Speech and
Hearing Research" Vol. 34, pages 379-385. This is also a case study
about an individual with severe hearing loss who has otoacoustic
emissions. Once again, these OAEs in the presence of severe hearing loss
are attributed to some surviving OHCs but damaged IHCs or nerve fibers.
The authors of this study go on to discuss several other studies that
found otoacoustic emissions in people with severe or profound hearing
loss. They criticize these studies for lack of adequate controls and
suggest that the measured OAEs may merely be artifacts caused by
nonlinearities of the measuring system or improper fit of the probe tube
in the ear canal.
This brings to light the need to use adequate controls when using OAEs in
daily clinical applications. I still reserve a healthy skepticism about
the use of OAEs beyond as a screening tool. Is anybody else having
trouble warming up to clinical use of OAEs?
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