Simple Explanation

Vibrations that travel through a medium (solid, liquid, or gas) and are detected by the human ear, typically in the range of 20 Hz to 20,000 Hz.

Concise Technical Definition

Sound refers to vibrations that propagate through an elastic medium (solid, liquid, or gas) and are detectable by human ears. The frequencies of sound typically range from 20 Hz to 20,000 Hz, with sound at any given point in air being a rapid variation in air pressure around the normal atmospheric pressure. In other words, sound is a disturbance or fluctuation in the surrounding medium that transmits energy, which our ears interpret as sound. These variations in pressure create waves that we perceive as sound.

Layman-Friendly Analogy

Think of sound like ripples in water—when you throw a stone into a pond, it creates waves that travel outward. In the same way, sound creates vibrations in the air (or other materials), and those vibrations move outward to reach your ears.

Industry Usage Summary

Sound is the basis of all audio and acoustic engineering, from music production to architectural acoustics. Engineers and designers use sound measurements and characteristics (like frequency, amplitude, and wavelength) to optimize audio systems, control sound in performance spaces, and enhance listening experiences. Understanding how sound travels through various media and how it can be manipulated is key in industries ranging from entertainment to telecommunications, audio technology, and even healthcare (e.g., ultrasound).

Engineering Shortcut

Vibrations transmitted through a medium that produce audible pressure changes, typically in the range of 20 Hz to 20,000 Hz.

Full Technical Explanation

Sound is a mechanical wave that consists of pressure disturbances that travel through an elastic medium, such as air, water, or solids. These disturbances propagate as longitudinal waves, where particles of the medium move in the direction of wave propagation. The frequency of sound typically ranges from 20 Hz (sub-bass) to 20,000 Hz (ultrasound), which is the range detectable by human ears. Sound in air involves rapid variations in air pressure, causing molecules in the air to compress and rarefy in a regular pattern. This pattern of pressure fluctuations, when detected by the human ear, is perceived as sound. Acoustic engineers and scientists study the behavior of sound waves in different environments to better understand how sound interacts with materials and to design systems that can capture, transmit, and reproduce sound with clarity and accuracy.