Date of Award

5-2020

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Program

Speech and Hearing Science

Track

Audiology

Research Advisor

Patrick N. Plyler, Ph.D.

Committee

Ashley W. Harkrider, Ph.D Mark S. Hedrick, Ph.D. Patti Johnstone, Ph.D Devin McCaslin, Ph.D.

Abstract

It is well-documented that auditory thresholds decrease with age, which can be referred to as Age-related hearing loss (ARHL). ARHL is one of the most common conditions affecting older adults and is associated with several conditions including decreased postural stability and falls. Age-related changes to auditory function have been attributed to, through histopathological study, specific degradation of the sensory, supporting, and afferent structures of the cochlea. Vestibular function, as measured through vestibular evoked myogenic potentials (VEMPs) also show decreases with age. VEMPs are a measurement of evoked potentials generated by auditory stimulation of the utricle and saccule measured through a reduction in muscle potentials. Similar to ARHL, age-related changes to the vestibular sensory and supporting structures with specific degeneration of the saccule, utricle, otoconia, primary vestibular afferents have also been noted. Significant decreasesin postural control with age are also well-documented in literature attributed to multifactorial changes in function. Previous studies have found associations between vestibular dysfunction and hearing loss in specific pathologies. Additional associations between ARHL and decreased postural control have also been documented. However, only limited data has been reported evaluating the association of ARHL, decreased vestibular function, and postural control.

The results of this study indicated significant differences in VEMP findings for individuals with ARHL compared to an age-matched group with normal hearing. Additionally, significant correlations were noted across groups with decreases in hearing thresholds associated with decreases in VEMP amplitude and prolongation of VEMP latency. No significant differences between the ARHL and normal hearing group were noted for postural control measures. No significant correlations were noted for hearing thresholds and postural measures. These results are consistent with previous literature describing concomitant vestibular dysfunction in ARHL and other types of SNHL. The long-term goal of this line of this study is to evaluate the use of auditory function as a predictor of increased risk of falls and a possible criterion for subsequent balance function testing and intervention as needed as a means to reduce the risk and occurrence of falls in people with ARHL.

Declaration of Authorship

Declaration of Authorship is included in the supplemental files.

ORCID

http://orcid.org/0000-0002-2291-1660

DOI

10.21007/etd.cghs.2020.0504

2020-013-Doettl-DOA.pdf (218 kB)
Declaration of Authorship

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