Welcome to brain Stuff from how stuff works dot com where smart Happens. Hi. I'm Marshall Brain with today's question, what are MP three files and how do they work? A CD stores music using forty four thousand, one hundred digital samples per second, sixteen bits per sample, and two channels for stereo sound. This means that a CD stores about ten million bytes or ten megabytes of data per minute of music on a CD. A three minute song
therefore requires thirty megabytes of data on a CD. If you've ever tried to download files on the Internet, you know that thirty megabytes is a big file. If you're using a slow connection to connect to the Internet, thirty megabytes of data would take several hours to download. MPEG stands for the Moving Picture Experts Group, and they've developed
compression systems used for video data. For example, DVD movies, h d TV broadcasts, and ds A satellite systems all use MPEG compression to fit video and movie data into smaller spaces. The MPEG compression system includes a subsystem for compressing sound. It's called MPEG Audio Layer three, and we know it by its abbreviation MP three. MP three can compress a song by a factor of ten or twelve
and still retain something close to CD quality. So a thirty megabytes sound file from a CD reduces to three megabytes or so an MP three. When you download the MP three file and play it, it sounds almost as good as the original file. If you wanted to, you could download an MP three file, expand it back to its original size, and then record it on a writable c D so you can play it in a CD player. All that you're doing is converting back and forth between
different formats to make downloading easier. Do you have any ideas or suggestions for this podcast? If so, please send me an email at podcast at how stuff works dot com. For more on this and thousands of other topics, go to houstaff works dot com