I live in North Dakota. So no oceans near by. But a few years after moving into my new house, I started noticing the same hum. Wife has good hearing and could never hear it. When I built my house, I sound proofed the hell out of it. I wanted quiet!
For the longest time, I thought it was my anemometer. But then I could hear it with no wind. I started going all through my house trying to guess what it was. At one point, I turned off the main breaker to my house, and my gas line. When the wife was out of town of course. Made no difference!
So I concluded the sound isn't the house. I'm not near any kind of industrial sources. I'm almost a mile away from the highway.
But what told my wife it sounds like is someone with a Bobcat off in the distance. The sound wains in and out. What I found interesing in the article, is it mentioned diesel engines. And that's exactly what i hear!
The other part for me personally, is I am deaf from birth. But the frequency is above 5k that I lose signal. This sound is much deeper than that. And I have tinnitus from birth. But again in the high frequencies. So reading this article fits so well with what I'm hearing. I did not know about it.