Being next to a railway line you hear a train coming from a distance. It passes, loudly and the sound fades away as the train moves into the distance. ??This experience has a sense of space about it.

How peculiar then to hear a train travelling underneath your hotel in central London. No warning of its imminent arrival or departure but just a few moments of recognition as the train appears in your soundscape. Is this symptomatic of city living? A multitude of brief experiences?