What is Sound?

Sound is what we hear — people talking, music, city noise. There are also sounds we don’t hear, infrasound and ultrasound.

Sound is a huge part of our lives in many ways. We communicate with each other through sound. Warning sounds alert us to danger. Music, whether a concert in an orchestral hall or our own singing in the shower, brings enjoyment and richness to our lives. Sound has important applications in medicine, including stethoscopes and ultrasonic imaging.

Not all sound is good. Unwanted sound – noise – is omnipresent in modern society. Annoyance, loss of hearing, and nonauditory effects can result. Many researchers are addressing the problems. Approaches being investigated include techniques for reducing noise at the source, city noise mapping, highway noise barriers, active and passive hearing protectors, and more. To learn more about “acoustics”, the science of sound, click here.

Have a look at the various topics in this section to get a sense of the different aspects and descriptors of sound.

More information is available at many sources, some of which are listed in the Resources section.