## Conceptual Physics (12th Edition)

A sound of 30 dB corresponds to an intensity of $10^{-9} \frac{W}{m^{2}}$, which is $10^{3} = 1000$ times greater than the intensity of a 0 dB sound, $10^{-12} \frac{W}{m^{2}}$. This is discussed on page 394, and shown in Table 21.1.