The owl call I mistook for a car alarm for two straight years

For two years I heard a strange rhythmic sound outside my window at night and assumed, without ever really checking, that it was some neighbor's malfunctioning car alarm. It was a barred owl.

The actual call — sometimes described as "who cooks for you" — is distinctive once you know what you're listening for, and completely forgettable if you've already decided it's mechanical noise. I only figured it out because a birdwatching friend visited, heard it once, and named the species before I'd finished asking what she thought that annoying sound was.

The lesson stuck with me more than the owl itself: how much ambient nature gets filed under "background noise" simply because we've already decided, once, not to pay attention to it.

Related reading: The Beginner's Guide to Noticing More on Every Walk Outside.