| Summary: | Conventional clinical procedures for middle ear assessment have been used for several decades
but have shown limitations. Application of a new technology, wideband energy reflectance (ER), has
shown great potential. The ER measurement determines the proportion of acoustic energy reflected by
the middle ear, across a broad frequency range. Negative middle ear pressure (MEP) is a highly
prevalent, and mostly transient, form of middle ear dysfunction which effects ER measurement. Goals
of the present study were to examine various factors relating to the ER test: (1) test-retest reliability, (2)
the effects of pressure manipulations, (3) the effects of negative MEP, and (4) the effectiveness of a
corresponding compensation procedure. Data were collected in 48 adults and analyzed across the
frequency range from 0.223 to 8 kHz. Measurements were conducted using both ambient and dynamic
pressure methods, under three conditions: normal MEP, negative MEP, and compensated negative MEP.
Correlation between immediately repeated tests were strong for all frequencies. The sweeping
pressure procedure caused ER reduction for a few frequencies but differences were small. Thirty-five
subjects were able to produce a negative MEP ranging from -40 to -220 daPa. Negative MEP increased
ER at low- and mid-frequencies while decreasing ER at high-frequencies. Magnitude of changes and
frequency at which maximum change occurred increased when MEP became more negative.
Compensated negative MEP reduced ER at low- and mid-frequencies but increased ER at high-
frequencies. The present study demonstrated that negative MEP altered ER in a frequency-specific
pattern. The compensation procedure eliminated the effects of negative MEP. Immediate test-retest
reliability of the ambient ER test was excellent. Both probe reinsertion and manipulation of the ear
canal and middle ear pressure produced minimal effects. === Thesis (Ph.D.)--Wichita State University, College of Health Professions, Dept. of Communication Sciences and Disorders
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