Estimated Prevalence of Functional Hearing Difficulties in Blast-Exposed Service Members With Normal to...

Area of Science:

• Auditory Neuroscience
• Military Medicine
• Audiology

Background:

• Young adults in military service with normal hearing often report difficulty understanding speech in noise.
• Explosive blast exposure is common among these service members.
• Blast exposure may lead to auditory deficits even with normal audiometric thresholds.

Purpose of the Study:

• To determine the prevalence of functional hearing and communication deficits (FHCD) in healthy Active-Duty service members.
• To investigate the impact of blast exposure and audiometric thresholds on auditory performance.
• To identify service members at risk for FHCD despite normal hearing.

Main Methods:

• Approximately 3400 Active-Duty service members with normal or near-normal hearing thresholds were assessed.
• Four hearing tests and a 6-question survey were used to evaluate FHCD.
• Participants were grouped by blast exposure severity and hearing threshold levels.

Main Results:

• The probability of hearing difficulty increased 2-3 times with close blast exposure or slightly elevated thresholds.
• Service members with both blast exposure and mild hearing loss had 4-5 times higher risk for abnormal auditory performance and subjective reports.
• Blast-exposed individuals were 2.5 times more likely to experience hearing deficits.

Conclusions:

• Approximately 33.6% of Active-Duty service members with normal hearing may be at some risk for FHCD.
• About 5.7% (72,000) are at high risk and currently undetected by fitness standards.
• Further testing is crucial to assess auditory processing damage and develop targeted therapeutic strategies.