If the buzz changes pitch or timbre during those 12 minutes then the initial noise-profile will no longer match the unwanted sound.
If the buzz is mains-hum there a plugins specifically for that which are worth a try.
If the buzz changes pitch or timbre during those 12 minutes then the initial noise-profile will no longer match the unwanted sound.
If the buzz is mains-hum there a plugins specifically for that which are worth a try.