Analysis of audiometric data as a contribution to the noise risk assessment

METHODS: We have matched the annual rate of change for average of at 3, 4 and 3-4 kHz between 2617 workers of 15 Italian thermoelectric power plants exposed to noise and 90 workers non-exposed (ANCOVA test controlling for relevant confounders: age and high frequency hearing threshold level). RESULTS: Overall, workers exposed to noise did not show a statistically significant hearing loss (F: 1.03 p = 0.30 for 4-6 kHz). Five subgroups in two power plants showed a significant hearing loss suggesting a specific re-evaluation of prevention strategies CONCLUSIONS: The statistical analysis of hearing loss progression in a population of workers exposed to noise can be an effective instrument of occupational risk assessment and monitoring of the effectiveness of prevention strategies.