Industrial acoustics and noise control helps to optimize communication and limit worker exposure in the workplace - typically in manufacturing or other heavy industries.
A large municipal transportation agency retained an NCAC member firm to develop a hearing conservation program for about 1000 employees. As part of the program, noise exposure surveys were carried out for a sample of all job functions. These surveys were carried out with time-history noise dosimeters that stored average noise exposures every minute during the worker's shift. The workers also wrote down the tasks they were assigned during the shift.
Although many of the employees were exposed to time weighted sound levels greater than 85 dB(A) during a shift because of traffic noise to which they were exposed, vehicle maintenance workers had particularly high exposures in excess of 90 dB TWA.
Comparing the task log with the exposures during the shift, the firm determined that the majority of the exposure of the maintenance workers was caused by removing mufflers with pneumatic chisels.
Changing the removal technique from chisels to using cutting torches reduced the exposures by more than 5dB TWA which represented a major reduction in the hazard to hearing and the potential to develop hearing loss.