I was thinking about writing a possibly continuously running monitoring / alarm app for noise sources. It would ring a bell and call the cops and the men from Ofcom if noise figures at particular bins departed significantly from a standard reference spectrum taken for that line. Or you could call recent spectra 'the new norm'.
Would it make sense to do it from QLM figures? I don't know what the proper definition of QLN is, and most importantly, whether or not the data is dynamically reported as instantaneous values.