Thesis
Using electrocochleography to hunt for evidence of hidden hearing loss in college students
University of Iowa
Master of Arts (MA), University of Iowa
Autumn 2019
DOI: 10.17077/etd.005192
Abstract
Hidden Hearing Loss (HHL) is a term used to describe individuals who present to the clinic with normal audiometric thresholds but with complaints of difficulty understanding speech in background noise. Because the pathophysiology of this condition is not fully understood, diagnosis can be challenging.
In 2016, Liberman et al. (2016) published results of a study they conducted comparing musicians, who he considered to be “at risk” for HHL with a control group of individuals who were majoring in communication sciences and disorders (CSD) and therefore assumed to be at a reduced risk for this condition. The goal was to identify a set of tests that might be used to help diagnose HHL. Consistent with their hypothesis that exposure to noise over long time periods can damage the peripheral auditory system and cause HHL, individuals in the “at risk” group (i.e. musicians) were found to have more concerns about hearing in background noise, elevated audiometric thresholds for frequencies above 8 kHz and lower scores on a speech in noise task than CSD majors. They also recorded electrocochleograms (ECoG) and found that individuals in the “at risk” group also had larger SP:AP ratios compared with the CSD majors. They interpret this finding as evidence that the pathophysiology of HHL may be related to damage to the synapse between the hair cells and the auditory nerve.
There is considerable evidence in the literature that musicians have relatively high levels of noise exposure over their lifetimes. The goal of the current study was to see if the findings reported by Liberman et al. (2016) could be generalized to a group of subjects who had less extensive amounts of noise exposure. Toward that goal, we recruited a group of 16 individuals, none of whom were professional musicians, but who reported varying amounts of noise exposure. We queried them about how often they used personal headphones and we measured “typical output levels from their devices”. We also asked about their history of recreational or occupational noise exposure and used these metrics to form two different groups, one “at risk” and the other at “low risk” for HHL. We found that individuals in our “at risk” group had significantly elevated audiometric thresholds for pure-tones above 8 kHz compared to the subjects in the “low risk” group. We measured speech perception in background noise and recorded ECoG responses from each subject. While the mean trends in the current study are in the same direction as those identified by Liberman et al. (2016), our results, while clearly underpowered, were not found to be statistically significant. If that trend holds with additional data collection, it suggests the battery of tests used in the Liberman et al. (2016) study may have limited sensitivity.
Details
- Title: Subtitle
- Using electrocochleography to hunt for evidence of hidden hearing loss in college students
- Creators
- Brianna Kelley
- Contributors
- Carolyn Brown (Advisor)Inyong Choi (Committee Member)Eun Kyung Jeon (Committee Member) - University of Iowa, Communication Sciences and Disorders
- Resource Type
- Thesis
- Degree Awarded
- Master of Arts (MA), University of Iowa
- Degree in
- Speech Pathology and Audiology
- Date degree season
- Autumn 2019
- DOI
- 10.17077/etd.005192
- Publisher
- University of Iowa
- Number of pages
- ix, 30 pages
- Copyright
- Copyright 2019 Brianna Kelley
- Language
- English
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (pages 23-24).
- Public Abstract (ETD)
Hidden Hearing Loss (HHL) is a term used to describe individuals who present with normal audiometric thresholds but complaints of difficulty understanding speech in background noise. Because the cause of this condition is not fully understood, diagnosis can be challenging.
In 2016, Liberman et al. (2016) published results of a study comparing a group of musicians they considered to be “At Risk” for HHL with a control group considered to be at “Low Risk”. Their goal was to identify a test battery that could help diagnose HHL. Liberman et al. (2016) showed that the “At Risk” group had significantly elevated thresholds for frequencies above 8 kHz, enlarged SP:AP ratios, and poorer performance on speech-in-noise tasks.
This study is a replication of Liberman et al. (2016) but focuses on a population with less significant amounts of noise exposure. We report results from 16 individuals who regularly use personal headphones and classified them into “At Risk” and “Low Risk” groups based on the duration of headphone use, listening levels and history of occupational/recreational noise exposure.
Like Liberman et al. (2016), we found our “At Risk” group to have significantly elevated thresholds compared for frequencies above 8000 Hz. Mean trends in this study paralleled those reported by Liberman et al. (2016) but were not found to be statistically significant. Additional research with a larger subject group is needed to establish sensitivity of this test battery.
- Academic Unit
- Communication Sciences and Disorders
- Record Identifier
- 9983779998902771
Metrics
30 File views/ downloads
106 Record Views