$4\mathrm{.}2$ Using the Octave Band Attenuation Data provided for Ear Defender $1$ given here, calculate what the worker's noise exposure would be when wearing them. Refer to ISO $4869-2$:$2018$ and their Excel files provided.

$4\mathrm{.}1$

$\backslash$table$[[$Octave Band Attenuation Data $($dB$)-$ Ear Defender $1,],[\backslash$table$[[$Frequency$],[($Hz$)]],125,250,500,1000,2000,4000,8000],[\backslash$table$[[$Mean$],[$attenuation$]],12\mathrm{.}7,13\mathrm{.}2,22\mathrm{.}9,21\mathrm{.}6,31\mathrm{.}9,20\mathrm{.}2,39\mathrm{.}5],[\backslash$table$[[$Standard$],[$deviation$]],5\mathrm{.}5,2\mathrm{.}1,2\mathrm{.}6,2\mathrm{.}3,2\mathrm{.}5,3\mathrm{.}5,3\mathrm{.}2]]$

It is extremely important to note that hearing protectors must be fitted and worn correctly at all times. Consider a worker with an $8$ hour shift in a $100dB(A)$ noisy environment but wearing hearing protectors that offer $20dB(A)$ noise reduction; the noise level at the worker's ear is $80dB(A).$ What is the noise exposure to the worker if the protectors are removed, even for a short while, or if the protectors are not fitted correctly? Using the equations given we can look at the $L_{\text{A}\text{e}\text{q},8}$ for

the protectors removed for $6$ minutes in the day $(0\mathrm{.}1$ hours$)$ exposing the ears to $100dB(A)$ for those $6$ minutes, and $80dB(A)$ for the rest,

the protectors removed for $12$ minutes in the day $(0\mathrm{.}2$ hours$)$ exposing the ears to $100dB(A)$ for those $12$ minutes, and $80dB(A)$ for the rest,

etc.