Sound is invisible, and that which cannot be seen is often overlooked or taken for granted.

The auditory sense connects us to the world in a way other senses cannot: acoustics mediate emotional and intellectual relationships between sound-producers and receivers.  Waves lapping against unique rock formations on a shoreline, coyotes howling deep in the woods, a bell-tower chiming every hour – these types of sounds emotionally connect us to the environments in which they occur.  When they are considered in context of the network of other sounds that surround them, it is possible to discover information about the interactions between sounds.  As a result, deep levels of awareness and knowledge about locations can be attained through sound.  To truly understand the complexities of an environment, its acoustic properties deserve to be studied.

Acoustic environments, properly termed “soundscapes,” are communication systems.  They contain information that reveals: the communities of organisms that reside within an area and their interactions; seasonal changes; information about space and time; cultural and historical events or entities, unique to a locale; and other relationships.

Since industrialization began, natural soundscapes have increasingly been threatened.  As Luigi Russolo, an experimental composer, stated:

“In antiquity there was only silence. In the nineteenth century, with the invention of the machine, Noise was born. Today, Noise triumphs and reigns supreme over the sensibility of men.”

Human generated sounds are typically louder and more powerful than natural sounds and thus can “mask” them, reducing or eliminating their audibility.  Hence, natural sounds and soundscapes are threatened by the pervasiveness of non-biological sounds.  The threat to natural or historically important sounds consequently threatens our emotional connection to them: if sounds disappear due to excessive sound-masking and habitat or historical destruction, amongst other threats, our ability to hear them would be lost.  Deprivation of important sounds not only damages ecosystems where organisms depend upon acoustic communication, but also dampens our emotional association to environments.

Various organizations, such as the National Park Service, monitor the acoustic properties of soundscapes to determine the acoustic-state of environments.  From such initiatives, soundscape preservation programs have been established that aim to protect wild and historical soundscapes.

Carleton College, a small liberal arts college in Minnesota, protects the Cowling Arboretum (Arb) that spans 880-acres and has a diversity of prairies, deciduous and coniferous forests, and waterways.  The Arb is a vital resource to Carleton and the larger community for eduction, research, recreation, and simply its pristine beauty.  To determine how human-generated and natural sounds interact within this environment, I studied the Arb’s soundscape during the Fall of 2012.

The overall objectives were to determine if a portion of the Arb, Best Woods, is acoustically healthy and to classify the sounds that compose the Arb’s soundscape.