Otoacoustic Emissions in Noise-Induced Cochlear Damage in Artillery Soldiers

Abstract

Aim: Study the utility of distortion product otoacoustic emissions (DPOAEs) in the detection of preclinical noise-induced hearing loss (HL) in artillery soldiers. Materials and Methods: This cross-sectional study included all male subjects aged 18-35 years from the Indian Army and general civilians. Subjects underwent pure tone audiometry and DPOAE test. DPOAE parameters of subjects with normal hearing, nonexposed (control group 1 [CG1]) and noise exposed, HL (control group 2 [CG2]) were compared with noise exposed normal hearing (study group [SG]). Results: Mean DPOAE amplitude and sound to noise ratio of SG at all frequencies were significantly more than CG2 and less than CG1. SG had lower proportion of ears with absent DPOAEs than CG2, but higher than CG1 at all frequencies. Conclusions: Hearing loss is common among artillery soldiers. Artillery soldiers with normal hearing are more likely to develop HL due to impaired DPOAEs as compared to civilians with no history of noise exposure. Adequate safeguards are necessary to prevent handicap.