I mean , if  if you have , uh , fair assurance that , uh , the noise is  is quite stationary , then the smartest thing to do is use as much data as possible to estimate the noise , get a much better estimate , and subtract it off.
Mm - hmm.
But if it 's varying at all , which is gonna be the case for almost any real situation , you have to do it on - line , uh , with some forgetting factor or something.
So do you  is there some long window that extends into the past over which you calculate the average ?