Effect of impulsive noise on auditory efferent system in firearm users.

Background: Exposure to high-intensity impulsive noise, such as firearm blasts, can lead to subclinical cochlear and efferent system damage that is not detectable by standard audiometry.

Objective: This study aimed to evaluate the effects of firearm noise exposure on the auditory efferent system in military personnel.

Methods: This prospective study included 45 firearm-using military personnel and 45 non-exposed controls. Participants underwent pure-tone and speech audiometry, DPOAE, and contralateral suppression testing to assess MOCR. Bonferroni correction was applied for multiple comparisons.

Results: After correction ( < 0.0027), thresholds were significantly higher at 4 kHz in the right ear and at 0.25, 2, and 4 kHz in the left ear. Firearm users also had higher pure-tone averages and speech reception thresholds, and lower speech discrimination scores than controls. Among DPOAE and MOCR measures, only the 2 kHz DPOAE amplitude in the left ear remained significant after correction ( = 0.001).

Conclusion And Significance: Impulsive noise from firearms may lead to subclinical cochlear dysfunction even in individuals with clinically normal hearing. DPOAE measurements, particularly at mid-frequencies, may serve as early indicators of noise-induced auditory damage. These findings underscore the importance of auditory monitoring and effective hearing protection in noise-exposed populations.