The sound has a unit of measurement. In physics, there are two measurements: in intensity (Watts per square meterI or in decibels. The most common unit of measurement is in decibels or dB. In fact, the threshold of hearing when it comes to measuring noise is in terms of decibels.
To convert decibels to intensity in W/^2, the equation is
dB = 10log(I/I0), where I0 is equal to 10^-16. It is an empirical constant for the standard reference intensity. Therefore,
12.5 = 10 log (I/10^-16)
I = 1.78 × 10^-15 W/m^2