Using the well-known fact that | watt re 1 wPa at 1 m is a sound level of 170.8690 dB, we 
can say that In our Gase 
P = 170.8750 dB re ! pPaat Im (10) 
= the NRAP source level. 
4. The above Valculations are probably accurate to about 2 percent, given the 
uncertainties in the input data. 
vay wah oops apes 
