Webopedia on Google+Webopedia on TwitterWebopedia on FacebookTech Bytes Blog
Main » TERM » M »

MP3 - MPEG Audio Layer 3

MP3 is the name of the file extension and also the common name of the type of file for MPEG-1 audio layer 3. Today, MP3 is the common audio format for consumer audio streaming and storage and the standard for the transfer and playback of music on most digital audio players. Because MP3 files are small, they can easily be transferred across the Internet.

What is MPEG Audio Layer 3?

Layer 3 is one of three coding schemes (layer 1, layer 2 and layer 3) for the compression of audio signals. Layer 3 uses perceptual audio coding and psychoacoustic compression to remove all superfluous information (more specifically, the redundant and irrelevant parts of a sound signal. The stuff the human ear doesn't hear anyway). It also adds a MDCT (Modified Discrete Cosine Transform) that implements a filter bank, increasing the frequency resolution 18 times higher than that of layer 2.

The result in real terms is layer 3 shrinks the original sound data from a CD (with a bit rateof 1411.2 kilobits per one second of stereo music) by a factor of 12 (down to 112-128kbps) without sacrificing sound quality.

Why MP3 is Popular

MP3 was designed by Moving Picture Experts Group and MP3s started appearing online in the 1990's. The music format became popular, quickly, because compression allowed the file to be as little as 1/10th of the original size. Remember, in the 1990's disk drives and storage space on consumer PCs was expensive.

The Problem with Statistics

We look at a few of the more troubling aspects of statistics and how these may be used to advance an agenda or skew the facts to someone's... Read More »

29 Free Android Apps for Cash-Strapped Students

From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »

Sharing Threat Intelligence

A growing number of startups make the sharing of threat intelligence a key part of their solutions. Read More »

The 7 Layers of the OSI Model

The Open System Interconnection (OSI) model defines a networking framework to implement protocols in seven layers. Use this handy guide to compare... Read More »

Network Fundamentals Study Guide

Networking fundamentals teaches the building blocks of modern network design. Learn different types of networks, concepts, architecture and... Read More »

Computer Architecture Study Guide

This Webopedia  study guide describes the different parts of a computer system and their relations. Read More »