It's like tracing your finger along an old map, except it's a map of noises. Ever heard a foghorn and thought about where it came from? The echo is its diary entry, leaving a trace behind like a ghost. Imagine the sound of a steam whistle at dawn, it lingers in the air like an opera note just hanging around, waiting for someone to catch its breath.

Sometimes I wonder, do pigeons have a secret language of clicks and clucks? And what about the rustle of leaves, do they whisper tales from the past? Maps of sounds, they should be a thing. I bet they’d be more useful than a GPS sometimes. Remember that one time we tried to follow the map of sea shanties? We ended up lost in a café with the best scones.