At-ear noise levels under the helmet: a field study on noise exposure of young motorcyclists

Abstract

At-ear noise exposure assessments of motorcyclists, with the function of speed, would be unsafe as on-road data acquisition has certain constraints including the operations and portability of appropriate instrument. Currently, there are no standardized protocols and methods for measuring the noise under motorcycle helmets. Furthermore, standard permissible noise emission levels for commuter motorcyclists are also not defined. Therefore, this study was aimed to investigate the motorcycle noise exposure assessments in realistic environment among young riders. A personal dosimeter was utilized to calculate the daily noise exposure level (L_Aeq, 8h) under three different standards including: OSHA-HC (Occupational Safety and Health Administration, Hearing Conservation), OSHA-PEL (Permissible Emission Level) and ACGIH/NIOSH (American Conference of Governmental Industrial Hygienists/ National Institute of Occupational Safety and Health). The study design consisted of noise assessment of riders (age range:19 to 25 years) at-ear under the open-face helmet in-realistic situation (main road to the motorway) motorcycling in dry weather conditions.  Personal dosimeter results (n=52) revealed the average noise exposure level of 93.64 dBA, 92.51 dBA, 95.29 dBA for OSHA-HC, OSHA-PEL and ACGIH/NIOSH respectively. The mean Time-Weighted Average (TWA) was 76.82 dBA, 75.69 dBA, 85.16 dBA for OSHAHC, OSHA-PEL and ACGIH/NIOSH respectively. Under the ACGIH and NIOSH standard, the TWA for motorcyclists is at hazardous limits, which requires further investigations associated with health effects on riders. Standardized methods and configurations should be set for assessing noise exposure related to the motorcycling.

Keywords: Motorcycle noise, Wind noise, Dosimeter, OSHA, ACGIH