Can You Hear That?

What if, out of nowhere, you started hearing a low-frequency rumble, like a truck idling right outside your home, in the middle of the night, every night for weeks and months on end -- and no one else could hear it?

What if, out of nowhere, you started hearing a low-frequency rumble, like a truck idling right outside your home, in the middle of the night, every night for weeks and months on end -- and no one else could hear it?