Sound provides an often-ignored element of our conceptualisation of the urban fabric. The power of music, sound and noise to denote place and demarcate space is used here to develop the idea of a sonic ecology. The paper attempts to map the relative order of this unseen city and to theorise its spatial and temporal patterning. The sonic ecology, a relatively persistent and chronologically ordered quality to sound in urban space, is used as a means of examining the distribution of sound and to weigh the broader social impact of these qualities. The ambient soundscape of the street is made up of a shifting aural terrain, a resonant metropolitan fabric, which may exclude or subtly guide us in our experience of the city, thus highlighting an invisible yet highly affecting and socially relevant area of urban enquiry.