IN THE NAME OF GOD

I want to calculate Energy loss in pipe or orifice when I know the sound level at a defined distance from it.

for example we consider a 20" methane pipe that an orifice plate has installed on it and we measured 101 db noise at 3 ft distance from orifice. (Methane flow rate=40200 kg/h , Upstream Pressure=53.7 Bar,abs , Upstream Temperature=95 degC)

How I can calculate the energy witch losses by sound?