ABSTRACT
Complex noise is the dominant type of noise in workplaces. It can cause more serious hearing loss than steady-state noise. The existing noise measurement and evaluation standards based on the "equal energy hypothesis" are not completely suitable for complex noise. This paper introduced the status quo of workplace noise measurement and assessment techniques, and the research progress of workplace complex noise measurement and assessment techniques. In terms of future research in this area, four proposals were made, including to improve associated population database, develop and revise noise-related standards, establish methodology of kurtosis adjustment, and identify the incidence characteristics of kurtosis-related occupational hearing loss. The paper also introduced the special column "Measurement and assessment techniques of complex noise in the workplace".
ABSTRACT
Complex noise with impulse or impact property is common in workplace, and its damage on the auditory system is greater than that of steady-state noise. At present, the noise exposure measurement and evaluation indicators widely used in the world mainly include the equivalent continuous sound level and the cumulative noise exposure, both are based on the equal energy hypothesis(EEH). EEH only considered the damage of noise energy on the auditory system, but ignored the effect of temporal characteristics of noise, and underestimated the degree of hearing loss associated with complex noise. This paper first introduced the limitations of current noise exposure assessment standards at home and abroad, then introduced the definition of temporal kurtosis and the calculation method of its related energy indexes(such as cumulative noise exposure and equivalent continuous A-weighted sound pressure level), and further summarized the effectiveness of temporal kurtosis as an auxiliary parameter of noise energy in assessing the risk of hearing loss caused by complex noise, providing a rationale to supplement the existing noise assessment standards.