Study on Noise Levels Generated due to Jack Hammer Drills in Granite Quarries

In this study, environmental noise and operator noise dose generated by jack hammer drilling were monitored in seven granite quarries in South India. The ambient noise was monitored at different distances and directions from the source. The maximum noise level was found in the downwind direction. The correlation study between distance and noise level was carried out to determine the safe zone limit for each quarry. To know the combined influence of compressive strength, rock density and distance, multiple regression analysis of data was conducted and a model was developed for the prediction of noise levels. Model adequacy was checked using F-statistics, normal distribution curve and correlation between predicted and measured values of noise levels. The operator noise dose in each quarry exceeded the prescribed limit. However, it can be controlled by providing ear plugs/ear muffs and by properly maintaining the jack hammers.