Simple Explanation

A surround-sound format with five main speaker channels and one subwoofer channel for bass—often called “5.1.”

Concise Technical Definition

Dolby Digital (AC-3) is a lossy audio compression format supporting up to 5.1 discrete channels: front left, center, front right, surround left, surround right, and a separate low-frequency effects (LFE) channel.

Layman-Friendly Analogy

Like having a sound system where each speaker gets its own part of the action—dialogue, effects, and music come from different directions.

Industry Usage Summary

Dolby Digital is one of the most widely adopted multichannel audio formats in DVDs, broadcast TV, Blu-rays, and streaming services. It was a major step forward in home theater and cinema audio, offering discrete surround playback in a compact format.

Engineering Shortcut

AC-3 codec, 5.1-channel lossy surround format with discrete speaker feeds.

Full Technical Explanation

Dolby Digital, also known as AC-3, is a digital audio coding standard developed by Dolby Laboratories. It provides up to six discrete audio channels: five full-bandwidth channels (20 Hz to 20 kHz) for front left, center, front right, surround left, and surround right; plus one low-frequency effects (LFE) channel for bass below 120 Hz. Originally developed for cinema and later standardized for DVDs, HDTV, and streaming platforms, it uses perceptual coding to compress data efficiently while preserving intelligibility and spatial cues. Dolby Digital also supports downmixing for stereo playback.