Analysis of Occupational Noise Exposure in Bus Drivers

The noise measurements were intended to quantify the equivalent sound pressure level inside the vehicle, close to the drivers' right ear. For this purpose, the Brüel & Kjaer 2238 sound analyser was used, covering LAeq, LAmax and LAmin measurements. The subjective assessments consisted of a questionnaire containing questions regarding noise discomfort in a sample of 200 drivers. Noise exposure was assessed in 80 vehicles of four different models: conventional, light, minibus and articulated. The data collected from the objective measurements were transferred to Brüel & Kjaer's Protector 7825 software for further analysis. The subjective assessment data were tabulated to display the results in a quantitative manner. The results showed statistical differences in noise between different bus models and between vehicles with different engine layouts. Analysis of the questionnaire did not reveal any significant difference between drivers working with different bus models, but a 36% prevalence of noise annoyance was found in the sample of drivers.