Blast Exposed Veterans With Auditory Complaints

The purpose of this study is to study blast-exposed Veterans who report hearing handicap but show normal or near normal results on standard audiometric testing. The characteristics and nature of their auditory and auditory-related skills will be examined, along with whether coexisting PTSD contributes to the hearing problems of these Veterans. In a preliminary treatment study, a sub-sample of these Veterans will be fitted with mild-gain hearing aids to determine if they benefit from low-level amplification of high-frequency sounds.

The purpose of this study is to study blast-exposed Veterans who report hearing handicap but show normal or near normal results on standard audiometric testing. The characteristics and nature of their auditory and auditory-related skills will be examined with a battery of behavioral and physiologic measures. The potential contributions of co-occurring PTSD also will be evaluated. In a preliminary treatment study, a sub-sample of the targeted Veterans will be fitted with mild-gain hearing aids to determine if they benefit from low-level amplification of high-frequency sounds. This study consists of two parts. In Part 1, four groups of Veterans, aged 20 - 50 years, will complete a battery of auditory and auditory-related assessments to better understand the deficit sources and patterns. The assessment measures will consist of questionnaires, behavioral tests, and auditory physiologic measures. One group will consist of blast-exposed Veterans with auditory problems but no PTSD. The second group will consist of blast-exposed Veterans with auditory problems plus PTSD. The third group will consist of Veterans with PTSD but no reported auditory problems, and the fourth groups will be a normal control group. In Part 2 of the study (clinical trial portion), a smaller group of participants from the first and second groups will be fitted with mild-gain open-fit hearing aids to determine if they benefit from mild high-frequency amplification. Changes in hearing handicap and speech perception will be compared from baseline to 6-months post-fitting. Perceived hearing aid benefit, hearing aid use time, and intent to continue use will be measured at the end of a 6-month treatment period. A delayed treatment group will be formed from group 1 and will be followed over a 12-month period with hearing aids fitted at 6 months. The participants will be assigned randomly from Part 1 of the study. The information obtained from this study will help us understand the auditory problems experienced by blast-exposed Veterans and eventually contribute to the development of an efficient and effective assessment battery and intervention approaches.

hearing impairment, post-traumatic stress disorder, traumatic brain injury, auditory processing disorder

The primary study was diagnostic, with a goal of better understanding and determining the best diagnostic assessment battery for capturing the hearing and auditory problems reported by blast-exposed Veterans. The secondary purpose was to implement a preliminary treatment study to determine if blast-exposed Veterans with hearing complaints, but normal audiometric data benefited from low-gain hearing aids. This secondary treatment study is the clinical trial portion of this study.

This group consisted of blast-exposed Veterans with auditory complaints but normal audiometric test results. These Veterans were negative for significant PTSD. They were fitted with open-fit hearing aids that provided mild high-frequency amplification and were monitored for 6 months.

This group consisted of blast-exposed Veterans with auditory complaints but normal audiometric test results. These Veterans were comorbid for significant PTSD. They were fitted with open-fit hearing aids that provided mild high-frequency amplification and were monitored for 6 months.

This group consisted of blast-exposed Veterans with auditory complaints but normal audiometric test results. These Veterans were negative for significant PTSD. They were fitted with hearing aids after a 6-month delay. Their performance was monitored 6-months pre-fitting and for the 6 months after the fitting.

This group consisted of Veterans who completed the same pre-treatment diagnostic testing as the three treatment groups but were not enrolled in the hearing aid treatment protocol. This group included neurotypical Veterans with normal hearing and were negative for blast-exposure and PTSD.

This group consisted of Veterans who completed the same pre-treatment diagnostic testing as the three treatment groups but were not enrolled in the hearing aid treatment protocol. This group consisted of blast-exposed Veterans with auditory complaints but normal audiometric test results. They were negative for significant PTSD.

This group consisted of Veterans who completed the same pre-treatment diagnostic testing as the three treatment groups but were not enrolled in the hearing aid treatment protocol. This group consisted of blast-exposed Veterans with auditory complaints but normal audiometric test results. These Veterans were comorbid for significant PTSD.

This group consisted of Veterans who completed the same pre-treatment diagnostic testing as the three treatment groups but were not enrolled in the hearing aid treatment protocol. This group was negative for blast-exposure and hearing loss but positive for significant PTSD.

Self-perceived hearing handicap was measured with the Hearing Handicap Inventory for Adults (HHIA), pre- and 6-months post-hearing aid fitting. The minimum score is 0 and the maximum score is 100, with the higher score reflecting greater handicap (worse outcome). The data are presented as a comparison between the two questionnaire administrations (pre- and 6-months post-fitting). The null hypothesis tested was that there would be no difference between the HHIA administered at baseline (pre-fitting) and 6-months post-fitting for all groups.

The participants wore their hearing aids for 6 months-fitting (baseline to 6-months post-fitting). The delayed group had a 6-month delay prior to treatment.

The Abbreviated Profile of Hearing Aid Benefit (APHAB) was administered at the end of the treatment period (6-months post-fitting) to measure self-perceived benefit. The APHAB is a 24-item self-assessment inventory used to indicate the extent to which listeners experience listening difficulties (with and without hearing aids) in various settings. The questionnaire uses a 7-point scale that corresponds to the frequency with which difficulties are experienced (99 to 1% of the time). The APHAB was administered for both unaided listening and aided listening, and benefit was calculated by subtracting the mean aided scores from the mean unaided scores. Higher benefit scores (e.g., 99% unaided - 25% aided vs. 99% unaided - 50% aided) reflected greater benefit (better outcome) and negative scores were possible. The null hypothesis tested was that no hearing aid benefit would be demonstrated by any of the 3 groups at 6-months post-fitting.

The APHAB was administered 6-months post-fitting. The delayed group had a 6-month delay prior to the treatment (6-months of wearing the hearing aids).

The participants reported whether they would continue to use their hearing aids after the study has ended. The null hypothesis tested was that neither group would demonstrate a significant preference for retaining their hearing aids.

Hearing aid use time was the number of participants who wore their hearing aids for an average of at least 4 hours per day. The average number of hours that the participants used their hearing aids was measured by their hearing aid data logging systems. These data were collected at the end of the treatment interval for each participant and were considered a positive outcome if they wore their hearing aids at least 4 hours a day on average after 1 month of use. The null hypothesis tested was that none of the participants in the three groups would not demonstrate hearing aid use time 4 hours or more, on average per day.

The participants' speech perception was measured at the word level with the California Consonant Test (CCT). The CCT is a 50 item a closed-set word identification test. It was administered at 3 timepoints (pre-fitting, 1-week post-fitting, and 6-months post-fitting), with testing was completed in quiet and in background noise (speech babble, +3 dB signal/babble) at each timepoint. The participants were unaided during the pre-fitting testing but wore their hearing aids during the two post-fitting sessions. The outcome measure was the proportion of correct trials out of 50. A correct trial consisted of an accurate identification of the target word presented to the participant in the sound-field at 40 dB sensation level. The null hypothesis tested was that speech perception would not improve over the treatment intervals for the groups for either test condition (quiet and noise).

The CCT was administered immediately pre-fitting (unaided), 1 week post-fitting (aided), and 6 months post-fitting (aided).

Inclusion Criteria: age 20 - 50 years; U.S. Veteran; English-speaking; history of blast exposure and no history of blast exposure; history of PTSD and no history of PTSD; self-perceived hearing handicap and no self-perceived hearing handicap; normal or near normal pure tone hearing thresholds; history of brain injury and no history of brain injury; normal vision. Exclusion Criteria: hyperacusis; marked tinnitus; pure tone hearing thresholds consistent with a hearing loss; greater the 20/30 vision screening results (corrected or uncorrected); marked speech perception deficits

De-identified Individual participant data and the study data dictionary will be made available upon request to the PI (spratt@pitt.edu).

Data will be available at the conclusion of the study and after publication of planned study manuscripts. The time will not be limited.

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