Please answer questions about noise: a) Please calculate the sound pressure level, in dB, of a noise with a sound pressure of 1 Pa. Imagine two workers who were exposed to occupational noise for 8 hours per day over a 20- b) year career. Worker #1 was regularly exposed to 90 dB at frequencies of 1,000 and 2,000 Hz. Worker #2 was regularly exposed to 90 dB at frequencies of 100 and 250 Hz. Based only on these sound pressure levels and frequencies, which worker would be more likely to experience a "permanent threshold shift"? Why? c) over a 20-year career. Worker #1 was regularly exposed to 90 dBA at frequencies of 1,000 and 2,000 Hz. Worker #2 was regularly exposed to 90 dBA at frequencies of 100 and 250 Hz. Based only on these sound pressure levels and frequencies, which worker would be more likely to experience a "permanent threshold shift"? Why? Now imagine two other workers who were exposed to occupational noise for 8 hours per day d) that makes hockey pucks. The factory operates 12 hours per day, from 6:00 am to 6:00 pm. There are three machines used in the factory. The noise level in the factory varies depending on which machine is operating. Now imagine two different workers, Simon and Fraser, who are employed at a factory in BC Machine #1 operates 6:00 am to 10:00 am, and during this time workers are exposed to 85 dBA. Machine #2 operates 10:00 am to 4:00 pm, and during this time workers are exposed to 91 dBA. Machine #3 operates 4:00 pm to 6:00 pm, and during this time workers are exposed to 88 dBA. Simon and Fraser both work eight-hour shifts. Simon works from 6:00 am to 2:00 pm. Fraser works from 10:00 am to 6:00 pm. Assuming a maximum permitted exposure level for 8 hours of 85 dBA with a 3 dBA exchange rate, are these workers exposed above the noise exposure limit during their 8-hour work shifts? Please clearly show how you arrived at your answer.