SD45 cab sound question

The high hood SD45s have this awful screaming noise in the cab that starts when you get up to around 10 miles per hour, and it makes them miserable to drive. I don't own the other SD45 packs but the videos I've seen seem to show that this sound is also present in the UP unit but not the SP one. Does anyone know why this sound is present in all the other units but not the SP one? And can someone who owns the SP pack confirm that the cab sounds are indeed different from the others and the screaming sound is not present?