A Quantitative Analysis of Kurtosis Impact on Occupational Complex Noise-Induced Hearing Loss

Workers in industry settings are often exposed to complex noise, which poses a greater risk to hearing loss than continuous noise at equivalent energy levels. Previous studies have identified kurtosis as an essential metric for evaluating complex noise-induced hearing loss (NIHL). This study aimed to characterize the distribution of workers exposed to complex noise, examine the associations between kurtosis and changes in hearing thresholds at various frequencies, and explore kurtosis's role in estimating NIHL and its integration into occupational hearing loss prevention programs.

The study quantitatively analyzed data from 2400 workers exposed to industrial complex noise and 1520 non-noise-exposed workers in China. Both arithmetic and geometric average kurtosis were used to characterize the work-shift noise records. Linear regression models assessed noise-induced permanent threshold shift (NIPTS) across different frequency ranges.

For workers exposed to average noise levels between 80 and 92 dBA, increased kurtosis levels correlated with worsening NIPTS across frequencies from 0.5 to 8 kHz. However, the impact of kurtosis at lower noise exposure levels (70-79 dBA) remains uncertain.

Kurtosis is crucial for predicting hearing loss among workers exposed to complex noise at average levels of 85 and 90 dBA. The findings have potential implications for occupational safety and health, particularly for the recruitment of workers into hearing loss prevention programs. Further risk assessment analysis could use the noise kurtosis metric to examine the excess risk of NIHL associated with complex noise exposure.