Something of especial interest in the article that should be examined closer:

"Another recent spate of strange sounds reported from North Battleford to Saskatoon, Sask. was explained by a University of Saskatchewan professor as a naturally-occurring "electromagnetic noise.""

The "naturally-occurring electromagnetic noise" label does not seem to fit if you investigate further, at least regarding the magnitude of the recent noises. Perhaps the closest thing this statement has to offer is that it is probably "electromagnetic noise".
"Naturally-occurring", however - possibly?
the naturally occurring electromagnetic noise called auroral hiss
If this is the case, what can be surmised is that either the current solar activity has intensified to the point that this new phenomenon of extreme audible noise is an indicator of such - or that it is symptomatic of something much worse, such as the breakdown of our natural magnetosphere.

We are aware of the fact that the atmospheric experiments that have been conducted over the past 60 years are detrimental to our environment. We do know that the use of aluminum in chemtrails is destroying the protective ozone layer above us so it should come as no surprise that there will be side effects that manifest in differing ways.
The Importance of Aluminum Oxide Aerosols to Stratospheric Ozone Depletion 1991

Another scenario could be that the noises are a signature of ongoing HAARP experiments, which of course most of us know utilize EMF.

All of our senses are now being challenged and causes us to take notice of things that we might normally overlook. Some events however, are too hard to ignore. It's up to us to piece together the information because the mainstream is of no help whatsoever and their knowledge pool and investigative explanations fall suspiciously short.