Converting dB(A) into NR

[Cooky]

I am creating an Excel spreadsheet for my company which predicts the average acoustic pressure dB(A) when the sound power level is entered at each octave band. I've completed this part of the program and it seems to work ok.

I would also like to show the predicted NR level, but I can't find the formula to achive this.

Can anyone help?

Cooky

 

[bklauba]

Try:

http://www.engineeringtoolbox.com/29_341.html