Measurement of Non-Steady Noise and Assessment of Occupational Hearing Loss Based on the Temporal Structure of Noise

Noise-induced hearing loss(NIHL)has become a global public health problem,and the economic burden of hearing loss caused by noise exposure accounts for 19.6%of the economic burden of all risk factors in the workplace(1).The prevalence of occupational NIHL was estimated to be 10%in relevant occupational population in developed countries and 17%–39%(e.g.,textile and petrochemical industries),and 53%–67%(e.g.,cement and automobile industries)in developing countries in Asia,respectively.(2).In China,occupational noiseinduced deafness has become the second primary occupational disease after pneumoconiosis,with the number of reported cases increasing at an average annual rate of 18.68%from 2010 to 2019(3–4).The prevalence of occupational NIHL in the Chinese occupational population was 21.3%,of which 30.2%was related to high-frequency NIHL(an early sign of NIHL)(2).