Tech it or leave it - 3 : Sing a song of six ONEs ???

By Derick Mathew

 

Sing a song of six ONEs ???

There are a few of us who spend the whole day listening to music, and then there are the rest of us who cannot even imagine let alone spend a whole day with less than 8 hours of music. It has come to be fused that most of what we do and so we end up playing it while we walk, talk, eat, travel, and work using many devices that primarily use the MP3 format. This format gained its importance with the wide spread of the internet on which mp3 files were interchanged so much so that it was soon said that the passage of time saw the term MP3 becoming synonymous to Music.

Mp3 stands for MPEG-1 Audio Layer 3, (quite a mouthful isn’t it ???????) anyway it has come to be known as MP3 and the world embraced it. And it is with good reason that it was so widely accepted, MP3 is what people call a lossy compression algorithm, A fancy way of saying that it is stored in one way and decoded to be something similar (not “equal”) to the original copy, this means that the quality of the music seemed to be great while the space used to store a song would reduce drastically (An ordinary MP3 file is only about 1/10 -1/11 of the original file size). But as usual there is a trade off that is when space is saved a resulting loss in quality. So it can understood that the quality of an MP3 file would increases as it grew larger in size. The size of the MP3 file varies depending on something called the bit-rate. The normal bit rate of an MP3 file is 128 Kb/s (that is 1048576 zeros and ones every second).

Victor Hugo once said “Music expresses that which cannot be said and on which it is impossible to be silent.” And the MPEG, or Moving Picture Expert Group (You will hear about these guys a couple more times in future articles), must have thought along the same lines when they designed the MP3 format. The MPEG guys used a technique called “Perpetual Noise Shaping” which uses certain traits of the human ears such as :
The human ear can only hear some sounds that lies within a particular frequency range
It takes in some sounds better than other sounds
It takes in the louder of 2 or more sounds that are played together

The MPEG thought of using the Perpetual Noise Shaping by showing only parts of a file by using a mask, i.e. the mask allows encoding of only certain parts of the music files. The mask blocks the frequencies that the human ear cannot pick up [its kinda like ur phone’s signal which is outta range every once in a while :P ].

This write up is just the tip of the iceberg, to read more about the MP3 format check out the Fraunhofer-Gesellshaft Website “http://www.iis.fraunhofer.de/EN/bf/amm/products/mp3/mp3history/mp3history01.jsp”.

P.S. Fraunhofer - Gesellshaft is a German company that owns the patent for the MP3 format.