The loudness level of a sound, $D,$ in decibels, is given by the formula $$D=10 \log \left(10^{12} I\right),$$ where $I$ is the intensity of the sound, in watts per meter $^{2}$. Decibel levels range from $0,$ a barely audible sound, to $160,$ a sound resulting in a ruptured eardrum. Use the formula to solve Exercises.
What is the decibel level of a normal conversation, $3.2 \times 10^{-6}$ watt per meter $^{2} ?$