Sound

Overview

Sound is a type of energy in the form of a wave that travels through a medium, such as a guitar string, air, or water. Just as some waves have alternating peaks and valleys, sound waves have alternating regions of high density (compressions) and low density (rarefactions). These regions result from the energy pushing particles away from a source and into surrounding particles, where they collide, transfer energy, and thus propagate the sound wave before bouncing back.

The rate at which particles vibrate forward and back—the frequency—corresponds to pitch, while the severity of vibrations corresponds to loudness. Because sound requires the movement of matter particles, it cannot exist in the vacuum of space, and its properties vary according to the medium it travels through. For example, sound travels faster in denser, hotter materials, where closely-packed, fast-moving particles can quickly collide and transfer energy.

Virtually all animals hear via specialized structures that convert the energy of sound waves into electrical signals for the nervous system, provided the structures are sensitive enough to feel the vibrations. As with other waves, sounds can be absorbed, reflected, and interfere with one another, with overlapping vibrations producing unique sounds or canceling one another out.

1440 Findings

Hours of research by our editors, distilled into minutes of clarity.

Explore Science & Technology

Dive into the dynamic world of science and technology, where curiosity has brought about extraordinary understandings of the universe and creativity has led to the breakthroughs and innovations that have transformed our world. Explore a wide range of topics, from the natural and physical sciences to cutting-edge technologies and the people who shaped them, each of which is accompanied by carefully curated resources meant to inform, engage, and inspire those eager to uncover the nature of reality.

View All Science & Technology