Sound is important to humankind. I know it sounds clichéd but it is the truth. Sound is important component of communication. Almost all languages we know today are based on complex attributes and relations between symbols and sound. A world without sound could be a haunting and psychologically detrimental experience. There is a section of science that is dedicated to study sound perception. This scientific study of sound perception is called Psychoacoustics. It branched out from psychophysics and originated around 1945. Psychoacoustics is the model design used to create MP3 audio formats.
The Different Audio Formats
First of all what exactly is an audio format? Well, simply put an audio format is a medium for recording/storing various kinds of sounds and music. All forms of music that is available for consumers today are recorded and distributed using the various audio formats. The different audio formats range from Digital Linear PCM (LPCM) used in CD-DA to Digital PCM used in Bluespec CD. It is important to understand that some audio formats are used exclusively in movie making and is not primarily used for music. Some of these formats are Dolby Digital (AC-3), Sony Dynamic Digital Sound (SDDS) and Digital Theatre System (DTS) etc. However, we will only concentrate on digital audio formats used mostly but not always for music. The audio file formats can be divided into three (3) audio file formats:
- Uncompressed Digital Audio Formats; For e. g. WAVEform (WAV).
- Formats with lossless comprehension; For e. g. FLAC, Monkey’s Audio (APE), WavPack, TTA, ATRAC. This format also explores the Advanced Lossless formats used in audio formats like Apple Lossless (m4a).
- Formats with Lossless compression; For e. g. MPEG – 1 or MPEG – 2Audio Layer III (MP3), Digital DTS Audio, Windows Media Audio, Ogg Vorbis, Amr, Advanced Audio Coding (AAC) etc.
For the true music and audio lovers, what really matters is the quality of the audio file and the amount of space it consumes. Of all the audio formats, MP3 has been a preferred choice among people across the globe. As it falls under the category of Lossless compression, one must consider if the sound quality is being compromised in MP3’s.
Does MP3 Satisfy The Sound Quality Standards?
Moving Picture Experts Group (MPEG) designed MP3 as part of their MPEG – 1 standard and the future MPEG – 2 standard audio formats. The design uses a lossy compression algorithm to reduce the size of data required noticeably and to playback the audio file as close as possible to the original sound quality. So, how is this achieved? To answer this question we need to go back to the scientific term Psychoacoustic, which we had mentioned at the start. The lossy compression algorithm works on the design model of Psychoacoustic. It rejects and reduces certain parts of the audio file that are considered to be beyond the human auditory perception. In other words, parts that are less audible to the human hearing. This method or design ensures that sound quality standards are not compromised for the end user. For e.g. A MP3 file that is created using the lossy compression setting of 128 kbit/s will result in a file that is about 1/11 the size of the CD file but the sound quality would still be good. In conclusion, a MP3 audio file can be reduced in size without entirely compromising the original sound quality of the file. This is one of the main reasons, people prefer MP3 to other formats.
