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. 2021 Mar/Apr;42(2):290-300.
doi: 10.1097/AUD.0000000000000942.

New Metrics Needed in the Evaluation of Hearing Hazard Associated With Industrial Noise Exposure

Meibian Zhang  1 , Hongwei Xie  1 , Jiena Zhou  1 , Xin Sun  2 , Weijiang Hu  2 , Hua Zou  1 , Lifang Zhou  1 , Jingsong Li  3 , Ming Zhang  4 , Chucri A Kardous  5 , Thais C Morata  5 , William J Murphy  5 , Jane Hongyuan Zhang  6 , Wei Qiu  7
Affiliations

New Metrics Needed in the Evaluation of Hearing Hazard Associated With Industrial Noise Exposure

Meibian Zhang et al. Ear Hear. 2021 Mar/Apr.

Abstract

Objectives: To evaluate (1) the accuracy of the International Organization for Standardization (ISO) standard ISO 1999 [(2013), International Organization for Standardization, Geneva, Switzerland] predictions of noise-induced permanent threshold shift (NIPTS) in workers exposed to various types of high-intensity noise levels, and (2) the role of the kurtosis metric in assessing noise-induced hearing loss (NIHL).

Design: Audiometric and shift-long noise exposure data were acquired from a population (N = 2,333) of screened workers from 34 industries in China. The entire cohort was exclusively divided into subgroups based on four noise exposure levels (85 ≤ LAeq.8h < 88, 88 ≤ LAeq.8h < 91, 91 ≤ LAeq.8h < 94, and 94 ≤ LAeq.8h ≤ 100 dBA), two exposure durations (D ≤ 10 years and D > 10 years), and four kurtosis categories (Gaussian, low-, medium-, and high-kurtosis). Predicted NIPTS was calculated using the ISO 1999 model for each participant and the actual measured NIPTS was corrected for age and sex also using ISO 1999. The prediction accuracy of the ISO 1999 model was evaluated by comparing the NIPTS predicted by ISO 1999 with the actual NIPTS. The relation between kurtosis and NIPTS was also investigated.

Results: Overall, using the average NIPTS value across the four audiometric test frequencies (2, 3, 4, and 6 kHz), the ISO 1999 predictions significantly (p < 0.001) underestimated the NIPTS by 7.5 dB on average in participants exposed to Gaussian noise and by 13.6 dB on average in participants exposed to non-Gaussian noise with high kurtosis. The extent of the underestimation of NIPTS by ISO 1999 increased with an increase in noise kurtosis value. For a fixed range of noise exposure level and duration, the actual measured NIPTS increased as the kurtosis of the noise increased. The noise with kurtosis greater than 75 produced the highest NIPTS.

Conclusions: The applicability of the ISO 1999 prediction model to different types of noise exposures needs to be carefully reexamined. A better understanding of the role of the kurtosis metric in NIHL may lead to its incorporation into a new and more accurate model of hearing loss due to noise exposure.

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Conflict of interest statement

The authors declare they have no actual or potential competing financial interests.

Figures

Figure 1.
Figure 1.
Distributions of (A): age; (B) exposure duration; (C) A-weighted equivalent sound pressure levels (LAeq.8h); and (D) kurtosis value of the 2,333 noise-exposed workers.
Figure 2.
Figure 2.
The estimated marginal means (EMM) of underestimated NIPTS by ISO 1999 model at each kurtosis value across test frequencies for four noise level bins in two different exposure durations. (A) The EMM of NIPTS underestimation at each kurtosis value for our noise level bins in duration D≤ 10 years. (B) The EMM of NIPTS underestimation at each kurtosis value for four noise level bins in duration D> 10 years. Error bars indicate the standard error of the EMM.
Figure 3.
Figure 3.
The estimated marginal means (EMM) of the actual measured NIPTS at each kurtosis value across test frequencies for four noise level bins in two different exposure durations. (A) The EMM of the actual measured NIPTS at each kurtosis value for our noise level bins in duration D≤10 years. (B) The EMM of the actual measured NIPTS at each kurtosis value for four noise level bins in duration D> 10 years. Error bars indicate the standard error of the EMM.
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References

    1. American National Standards Institute (2003). Maximum permissible ambient noise levels for audiometric test rooms ANSI S3.1.−1999. New York.
    1. Burns W, and Robinson DW (1970). Hearing and Noise in Industry (Her Majesty’s Stationery Office, London: ).
    1. Canlon B, Borg E, and Flock A (1988). Protection against noise trauma by pre-exposure to a low-level acoustic stimulus. Hearing Res 34:197–200. - PubMed
    1. Clark WW (1991). Recent studies of temporary threshold shift (TTS) and permanent threshold shift (PTS) in animals. J. Acosut. Soc. Am 90:1, 155–163. - PubMed
    1. Davis RI, Qiu W, Heyer NJ, Zhao YM, Yang QL, Li N, Tao LY, Zhu LL, Zeng L, and Yao DH (2012). The use of the kurtosis metric in the evaluation of occupational hearing loss in workers in China: Implications for hearing risk assessment. Noise Health 14(61),330–342. - PubMed