A sound signal is a complex entity with multiple physical and attributes. The various properties of sound signal are influenced by their sources, transmissions and media.

Sound Is...

Technically, sound is a term for a mechanical longitudinal wave of compression and expansion moving through a medium (e.g., air, water, land). Many different approaches and applications attempt to integrate a signalís physical dimensions into a coherent visualization. The spectrogram integrates the time, frequency and intensity into a three-dimensional graph.

Sound Properties

The advent of digital technology has presented a wide array of ecological applications in acoustics by enabling the rapid and inexpensive deployment of instrumentation capable of measuring and storing acoustic data at large spatial and temporal scales. Even prior to digital technology, research was conducted on organism communication and signal production.

Sound in Ecology

The temporal characteristics and spatial variability of the soundscape should be measured through an array of stationary, automated sensors distributed across the landscape. A truly integrated acoustic sensing network would also monitor variables ancillary to acoustics and would be associated with remote sensed data to characterize landscape features.

Measuring Sound

As with most realms of scientific inquiry, categorization and characterization of the information is needed to facilitate our understanding of the acoustic elements of ecosystems. We use a classification system† that focuses on the two primary acoustic contributions to the soundscape, biological and geophysical sounds.

The Diversity of Sound

Ecological Analysis of the Soundscape

Purdue University

Copyright © 2005, Purdue University, all rights reserved. An equal access/equal opportunity university.† Purdue University, West Lafayette, IN 47907 USA, 765-494-4600

Department of Forestry and Natural Resources