Browse Definitions :
Definition

AC-3 (Dolby Digital)

AC-3, also known as Dolby Digital , is a perceptual digital audio coding technique that reduces the amount of data needed to produce high-quality sound. Perceptual digital audio coding takes advantage of the fact that the human ear screens out a certain amount of sound that is perceived as noise. Reducing, eliminating, or masking this noise significantly reduces the amount of data that needs to be provided. Dolby Laboratories developed two other perceptual coding systems, AC-1 and AC-2. Building upon Dolby's two previous coding systems, AC-3 was the first coding system designed specifically for multichannel digital audio. AC-3 is the sound format for digital television ( DTV ), digital versatile discs ( DVD s), high definition television ( HDTV ), and digital cable and satellite transmissions.

AC-3 is a 5.1 format, which means that it provides five full-bandwidth channels, front left, front right, center, surround left, and surround right. A low-frequency effect (LFE) channel is included for the sound needed for special effects and action sequences in movies. The LFE channel is one-tenth of the bandwidth of the other channels and is sometimes erroneously called the subwoofer channel. AC-3 also has a downmixing feature that ensures compatibility with devices that do not support the 5.1 format.

This was last updated in January 2011

Join the conversation

2 comments

Send me notifications when other members comment.

Please create a username to comment.

What is the difference between Dolby D and Dolby E?
Cancel
The LFE channel is more normally referred to as "low-frequency extension."
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

SearchSecurity

  • certificate authority (CA)

    A certificate authority (CA) is a trusted entity that issues digital certificates, which are data files used to cryptographically...

  • hacktivism

    Hacktivism is the act of hacking, or breaking into a computer system, for a politically or socially motivated purpose.

  • advanced persistent threat (APT)

    An advanced persistent threat (APT) is a prolonged and targeted cyberattack in which an intruder gains access to a network and ...

SearchHealthIT

  • Cerner Corp.

    Cerner Corp. is a public company in North Kansas City, Mo., that provides various health information technologies, ranging from ...

  • clinical decision support system (CDSS)

    A clinical decision support system (CDSS) is an application that analyzes data to help healthcare providers make decisions and ...

  • Health IT (health information technology)

    Health IT (health information technology) is the area of IT involving the design, development, creation, use and maintenance of ...

SearchDisasterRecovery

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

  • ransomware recovery

    Ransomware recovery is the process of resuming options following a cyberattack that demands payment in exchange for unlocking ...

SearchStorage

  • SSD (solid-state drive)

    An SSD (solid-state drive) is a type of nonvolatile storage media that stores persistent data on solid-state flash memory.

  • file system

    In a computer, a file system -- sometimes written filesystem -- is the way in which files are named and where they are placed ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...

Close