Acoustics Information Intro

Intro | Sound and Decibels | Outdoor Sound Propagation | Wind Turbine Sound | Noise Impact and Regulation

Intro: Sound and the Environment

Sound is all around us nearly all of the time. This collection of sounds in our environment is known as the ambient sound or soundscape. The composition of the soundscape determines much about what we think and feel at any moment. Within a controlled environment such as a theater, room, or automobile we determine the sound we experience. Outdoor sound is completely different as most if not all outdoor sound comes from sources that are not under our control.

When in the outdoors, humans greatly appreciate hearing the natural sounds within an ecosystem and the solitude of remote areas that can be experienced throughout Maine. The sound of a meandering stream, songbird, rustling leaves, spring peepers or the call of the loon are enjoyable to many. Others enjoy the sound of racing engine, diesel-powered lobster boat, rumbling Harley or a fighter jet at the air show.

Animals rely on their sense of hearing to communicate and recognize events around them. Birds call to each other and many species use sound perception to recognize sources of danger. Large ocean mammals such as whales rely on the transmission of low frequency sound under water to navigate and communicate over large distances.

The study of environmental acoustics relates to the role that sound (or noise) plays in the environment. Geographically, this is an extremely diverse area of study ranging from wilderness to urban settings and from airborne sound to the underwater sound environment of oceans and lakes. Environmental acoustics is most commonly associated with assessing the noise impact of land-based developments such as wind energy projects. The following provide an overview of acoustic terminology and wind turbine noise.