This methodology is borrowed from ecology, and can be illustrated with an example. The musician and soundscape ecologist Bernie Krause utilised it to uncover the impact of logging on wild life in Lincoln Meadow, 2000m up the Sierra Nevada Mountains. In 1988, a logging company was permitted to conduct 'selective' logging in the forest, on the promise that this procedure would not harm the local ecology. To the eye, the operation did indeed appear to make little difference. However, by taking controlled sound recordings before

and after the logging, Krause showed that our ears tell a different story, as is made plain by the spectrograms above. Their upper half reveal a palpable loss of ecological density and diversity. In subsequent visits over a period of 25 years, Krause showed that the forest failed to recover.

Two aspects of this example should be emphasised. The first is how the ear can be more discerning than the eye in appraising ecological environments. The second is how useful the spectrogram can be in furnishing demonstrable evidence of this, capable of underpinning political calls for environmental action.

METHOD - We intend to explore how useful this methodology might be in urban environments. In the natural world each habitat has its own sound signature, within which species and individuals have become organised into discernible sonic niches. In a city, recurrent human activities give rise to additional patterns of sound, which combine in a more chaotic way, and can disrupt natural ones.

These patterns are associated with urban design. By exploring these patterns, or rhythms, through sound we will be approaching them in an unusual and fresh manner, which could prove revelatory. Listening encourages awareness of the full spherical perspective around us, both at close proximity and beyond the visible boundary, all of this simultaneously.

The spectrogram is a map that adds to this already rich aural experience. Like the democratised aerial views of Google Earth, the spectrogram gives us a powerful tool to navigate and distinguish elements of soundscape far beyond the simple mimicry of regular sound recordings. It is an objective presentation of what occurs, not coloured by the idiosyncratic bias of human subjective experience. It can display rhythms heard across a span of time in a single image for simultaneous and instantaneous viewing. As an image which you can point to, it lends itself to shared analysis, discussion and persuasion.

The spectrogram has disadvantages as well. It lacks the direct emotional response one gains from hearing a soundscape. Because the sound itself is absent, it is difficult to identify a sound source in a spectrogram and even more difficult, for example, to understand what someone is saying.

However, the symbols and marks of a spectrogram have their own aesthetic appeal, and can convey their own meaning. We intend to exploit these aspects of the spectrogram in the outputs of the studio.