Yeah , yeah. Yeah , people do something. They  they , uh , they have some , um , uh , in  in cepstral mean subtraction , for short - term window  analysis windows , as is usually done , you 're trying to get rid of some very general characteristic. And so , uh , if you have any other information about what a general kind of characteristic would be , then you  you can do it there.
You can also  you can also reflect the data. So you take , uh  you know , I 'm not sure how many frames you need.
Uh - huh.
But you take that many from the front and flip it around to  a as the negative value.