Unit 6. Basic Level. Sounds Formats


WAV Sounds

 

The sounds with extension WAV (.wav) are sounds with a very good quality, concretely, its quality is lower than an original sound by 13 times, this quantity is more than acceptable if we take into account that, for example, the sound of a telephonic call is worse than a original sound by 100 times, and a sound which we listen in radio (FM) is worse than a original one by 24 times. Knowing this, we will understand that WAV could take a lot of space in the hard disc. (A song of 4 minutes occupies 50 MBytes in format WAV).

Is it necessary so high quality? Is it necessary that the sound would be completely pure? Evidently not, and because of this others formats of audio appear. Others formats that without losing quality save space in the hard disc (and in our Flash movies) and provide flexibility to these sounds.

The format of audio that have acquired major popularity is the format MP3. Let 's see why.

MP3 Sounds

 

The MP3 (.mp3) is a technology of compression of audio file. Its complete name is MPEG-1 Audio Layer 3 and it appeared 15 years ago with the objective of reducing the enormous size that the audio files (for example, the WAV) had until then.

MP3 succeeds in combining quality of sound with a size of small file, becoming an audio standard in Internet. Its key is in that an MP3 sound does not contain all the details of the audio, those which are not captables by the human ear, but exist in the original sounds. That's to say, if a detail of the sound cannot be audible by the human ear, why not delete it.

And that is indeed the case; the result is a practically identical sound (often completely identical, depending on the level of applied compression) to the original sound. Some very powerful methods of compression are applied to this sound without needless information, and the final result is a file of MP3 audio, with a good quality and very reduced size (then, the song of 4 minutes from the previous example occupies 3,9 Mbytes only), that allows us to save a nearly unlimited number of songs in our computer, in CDs or even work with them in Internet...



 
 
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January-2006.