Nit: Human sound localization is 'good' from about 200Hz to about 1600Hz. Other posters have the sound at ~440Hz, so humans should be able to localize the sound fairly well.
In this case, I think they're mostly referring to "The Hum"[0] that others have been talking about, since the article is about the source of this noise. When it's lower frequency and not this easy to locate, it would be great if there were some other way to go about it.
https://en.wikipedia.org/wiki/Sound_localization