(From applicant's proposal): The main theme of the proposed research is to increase our knowledge of the human middle ear and cochlea based upon the use of acoustic response testing in the ear canal. Such tests are inherently noninvasive so that it is hoped that the knowledge gained on basic mechanisms in hearing will have significance for clinical utilization.
The first aim i s to examine new forms of otoacoustic emissions (OAE), which will provide a clearer understanding of mechanical processes on the basilar membrane. Time-frequency representations of OAE transients will delineate the fine structure of the tonotopically organized cochlear dynamics, which is otherwise partially obscured by conventional waveform or spectral representations.
The second aim i s to assess middle-ear and cochlear mechanisms in an integrated manner using a power-transfer approach. Such an approach will combine aspects of wideband tympanometry, otoreflectance and OAE measurements to interpret power flow from the ear canal through the middle ear to the cochlea, and back.
The third aim will apply these new types and representations of OAEs and the power-transfer approach in large-scale studies of normal ears, and ears with middle-ear and cochlear impairments. The goal is to improve techniques to predict conductive, cochlear and mixed hearing losses, and to better understand how acoustic response variables can be combined, for example, across frequency or static pressure in the ear canal, in order to understand the underlying cochlear and middle-ear mechanics and coupling in normal and impaired ears. The results of the proposed experiments will provide useful data for theoretical modeling of the auditory periphery, and could significantly improve our ability to identify persons with conductive or cochlear hearing loss.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
1R01DC003784-01A1
Application #
2849034
Study Section
Special Emphasis Panel (ZRG1-IFCN-6 (01))
Project Start
1999-05-01
Project End
2004-04-30
Budget Start
1999-05-01
Budget End
2000-04-30
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Father Flanagan's Boys' Home
Department
Type
DUNS #
City
Boys Town
State
NE
Country
United States
Zip Code
68010
Keefe, Douglas H (2015) Acoustical transmission-line model of the middle-ear cavities and mastoid air cells. J Acoust Soc Am 137:1877-87
Keefe, Douglas H (2012) Moments of click-evoked otoacoustic emissions in human ears: group delay and spread, instantaneous frequency and bandwidth. J Acoust Soc Am 132:3319-50
Keefe, Douglas H; Goodman, Shawn S; Ellison, John C et al. (2011) Detecting high-frequency hearing loss with click-evoked otoacoustic emissions. J Acoust Soc Am 129:245-61
Keefe, Douglas H; Fitzpatrick, Denis; Liu, Yi-Wen et al. (2010) Wideband acoustic-reflex test in a test battery to predict middle-ear dysfunction. Hear Res 263:52-65
Werner, Lynne A; Levi, Ellen C; Keefe, Douglas H (2010) Ear-canal wideband acoustic transfer functions of adults and two- to nine-month-old infants. Ear Hear 31:587-98
Goodman, Shawn S; Fitzpatrick, Denis F; Ellison, John C et al. (2009) High-frequency click-evoked otoacoustic emissions and behavioral thresholds in humans. J Acoust Soc Am 125:1014-32
Keefe, Douglas H; Schairer, Kim S; Ellison, John C et al. (2009) Use of stimulus-frequency otoacoustic emissions to investigate efferent and cochlear contributions to temporal overshoot. J Acoust Soc Am 125:1595-604
Keefe, Douglas H; Ellison, John C; Fitzpatrick, Denis F et al. (2008) Two-tone suppression of stimulus frequency otoacoustic emissions. J Acoust Soc Am 123:1479-94
Keefe, Douglas H; Gorga, Michael P; Jesteadt, Walt et al. (2008) Ear asymmetries in middle-ear, cochlear, and brainstem responses in human infants. J Acoust Soc Am 123:1504-12
Abdala, Carolina; Keefe, Douglas H; Oba, Sandra I (2007) Distortion product otoacoustic emission suppression tuning and acoustic admittance in human infants: birth through 6 months. J Acoust Soc Am 121:3617-27

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