A PROSPECTIVE STUDY COMPARING HEARING LOSS IN FACTORY WORKERS USING NOISE-CANCELLING HEADPHONES VERSUS STANDARD HEADPHONES: A PTA AND OAE-BASED EVALUATION

Abstract

Background: Continuous exposure to industrial noise is a major risk factor for occupational hearing sincluding headphones, are commonly employed. This study investigates the protective efficacy of noise-cancelling headphones compared to normal headphones over a two-year period.

Objective: To prospectively evaluate the impact of headphone type on hearing outcomes using Pure Tone Audiometry (PTA) and Otoacoustic Emissions (OAE) in factory workers.

Methods: A total of 50 factory workers aged 25–50 years were enrolled and divided equally into two groups: one using noise-cancelling headphones (Group A) and the other using standard headphones (Group B). Baseline and annual hearing assessments were conducted using PTA and OAE. The primary outcome was the change in hearing thresholds and OAE responses over time.

Results: Group A demonstrated significantly smaller threshold shifts in PTA and preserved OAE signals compared to Group B. At 24 months, average threshold increase at 4 kHz was 6.3 dB in Group A versus 14.5 dB in Group B (p < 0.01). OAE signal amplitudes declined marginally in Group A but significantly in Group B (p < 0.05).

Conclusion: Noise-cancelling headphones offered significantly better protection against hearing deterioration compared to normal headphones. Implementation of noise-cancellation technology may be a valuable addition to occupational safety programs in high-noise environments.