BTW the worse thing that you can hear in a boiler room is complete silence. I mean by that you don’t hear anything whatsoever yet you see lights, on equipment running, etc. It means you have a major steam leak. It is above your hearing range but it literally silences everything else. We were warned about it. Spooky.
New one on me, and very strange. And you're right, that's spooky.
So, even if the basic freq is above your audio range, the amplitude of the steam-scream "deafens" you to all other sounds? That really is strange!
Thanx for posting. Filing under "things I never knew".