Why does it matter?
Soundwaves travel from the source of the sound to your ears. Sometimes too much noise can be a bad thing! A term used for unpleasant noise that disrupts daily life is noise pollution. Understanding the way that sound travels can help to reduce noise pollution with interventions like noise barriers or noise-cancelling headphones.
Noise barriers are usually used to block the sound of highway traffic noise. These tall barriers reduce the sound which enters a community by interfering with the transmittance of sound waves. A noise barrier will absorb some of the sound, reflect the sound back to the highway or force the soundwaves to take a longer path over the noise barrier. As sound travels farther, its waves become less and less energetic and therefore, less and less loud.