Chapter 5 - 5.5 - Exponential and Logarithmic Models - 5.5 Exercises - Page 408: 47c

$-200$ decibels

We have $\beta=10 \log (II_0)$ Plug in the data: Therefore, $\beta=10 \log (10^{-12} \times 10^{-8})= 10 \log 10^{-20}$ Or, $\beta = 10 (-20) \log 10 =-200$ Therefore, the sound level is $\beta = -200$ decibels