This research focuses on tinnitus caused by internal tones of presumed cochlear origin. Although the physiological basis of tinnitus is generally unknown, a major breakthrough has shown that some cases of tinnitus are linked to spontaneous otoacoustic emissions (SOAEs), acoustic energies which can be detected when a sensitive miniature microphone is inserted into the ear canal. Estimates of the prevalence of SOAE-caused tinnitus indicate that this pathology may affect 1 million Americans. Studies of SOAE-caused tinnitus have necessarily been limited to cases in which SOAEs could be measured. Because the details of the spectral analyses affect the emergence of SOAEs, the first experiment here examines the effect of various techniques on the appearance of SOAEs in the ear canal. Because tinnitus is often environmentally caused, the second experiment documents a case in which SOAEs were not heritable but appeared due to extrinsic factors. In addition to spectral analyses techniques, the attenuation characteristics of the middle ear and the properties of the tympanic membrane play a role in the emergence of SOAEs. Accordingly, it seems possible that more internal tones are generated than are measured as SOAES in the ear canal. The psychophysical similarity of tinnitus associated with SOAEs and tinnitus not so associated may be indicative of cochlear tinnitus. Experiments 3-9 expand the psychophysical armamentaria linking tinnitus and SOAEs. Using the pilot data from Experiments 3-9, preliminary data from Experiments 10 and 11 demonstrate that tinnitus may be caused by idiotones, internal tones of cochlear origin which may exist even when SOAEs cannot be measured. Finally, Experiments 12-14 are aimed at exploring the prevalence of cochlear tinnitus and palliatives for it.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC002483-04
Application #
2634081
Study Section
Hearing Research Study Section (HAR)
Project Start
1995-01-01
Project End
1998-10-12
Budget Start
1998-01-01
Budget End
1998-10-12
Support Year
4
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
City
College Park
State
MD
Country
United States
Zip Code
20742