Question $1$

$($a$)$ Determine the overall A $-$weighted sound pressure level in $\backslash (\backslash$mathrm$\{$dB$\}(\backslash$mathrm$\{$A$\})\backslash )$ of the measured sound pressure level $($SPL$)$ shown in Table Q$1-1.$

$(6$ marks$)$

Table Q$1-1$ Measured sound levels

$($b$)$ Given that the first center frequency is $200$ Hz ; determine the next three center frequencies in $\backslash (1/3\backslash )$ octave band.

$($c$)$ Determine the total sound levels of three combined sound sources whose SPL are $\backslash (90\backslash$mathrm$\{$~dB$\},80\backslash$mathrm$\{$~dB$\}\backslash )$ and $77$ dB $.$

$(3$ marks$)$

$($d$)$ Explain the effect of noise on people from the physical and psychological aspects.

$(5$ marks$)$

You may use the information in Table Q$1-2$ in your calculations.

Table Q$1-2$ Corrections of A$-,$ B$-,$ and C$-$weightings