THE ESTIMATION OF THE PREVALENCE OF HEARINGIMPAIRMENT FOR THE NOISEEXPOSED POPULATION IN CHINA BASED ON ISO/DIS 1999.2

Based on the noise survey in China and the application of ISO/DIS 1999.2 (1985) "Acoustics-Determination of occupational noise exposure and estimation of noise-induced hearing impairment", the hearing threshold level associated with age and noise (HTLAN) and its relation with hearing threshold frequency associated with age (HTLA) for the workers under 85, 90, 95, lOOOdB of noise exposure level L_EX.8h from 0.5k to 6kHz are obtained in this paper. The formulas for calculation of L_Aeq, HTLAN, H'=H+N-HN/120 in ISO/DIS 1999.2 and Gauss distribution are used in the work. The standard ISO/DIS 1999.2 has been proved to be applicable in China.