The life found within this Tibouchina tree illustrates one of the ways in which sound marks the passage from day to night in the natural environment.
Throughout the day subtle stridulations of crickets emanate from the Tibouchina’s foliage, often overwhelmed by the deafening crescendos of cicadas. En mass the cicadas’ collective voice lacks spatial perspective. This sonic projection has the advantage of dissolving individual voices, their collective call coming from everywhere yet nowhere. This disorienting sonic adaptation is an ideal survival mechanism against predators. The same technique is used by other diurnal insects and frogs, marking it as an important characteristic of daytime sound.
Never are voices so beautiful as on a winter’s evening, when dusk almost hides the body, and they seem to issue from nothingness with a note of intimacy seldom heard by day. Virginia Woolf. Night and Day, 1919.
The cover of darkness enables a myriad of insects to communicate with ease from the branches of the Tibouchina. In contrast to their daytime practise insects fearlessly stridulate in the dark, promoting their location to prospective mates. Whereas day necessitates the blurring of individual sounds, night allows a much greater definition of projection. Enough space is left between individual calls to create a sonic perspective which includes both a foreground and background. Without any visual cues it is still possible to locate individual sound events emerging from different points in the shadows.
Although night is usually connected with tranquility, in Australia at least, this seems at odds with the reality. For me it is the sounds of the night which sustain the most interest, listening into the darkness without the visual distractions of the day.