That means that  Mm - hmm. Yeah. So  so yeah , you have an  an estimation of the noise spectrum , but sometimes , of course , it 's  as the noise is not perfectly stationary , sometimes this estimation can be , uh , too small , so you don't subtract enough. But sometimes it can be too large also. If  if the noise , uh , energy in this particular frequency band drops for some reason.
Mm - hmm. Mm - hmm.
Mmm.
So in  in an ideal word i world  if the noise were always the same , then , when you subtracted it the worst that i you would get would be a zero. I mean , the lowest you would get would be a zero , cuz i if there was no other energy there you 're just subtracting exactly the noise.