Mm - hmm.
And um you  from that you  you estimate  or you estimate fine harmonic structure , whichev ei either way , it 's more or less the same. But  uh the thing is that um you then  can get rid of things that are not  i if there is strong harmonic structure ,  you can throw away stuff that 's  that 's non - harmonic.
Mm - hmm. Mm - hmm.
And that  that is another way of getting rid of part of the noise