Effect of impulsive noise on auditory efferent system in firearm users

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.

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

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.

After correction (p < 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 (p = 0.001).

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.