MP3 Reviews

MP3 Developments

In 1983, at the University of Buenos Aires, Oscar Bonello started developing a PC audio card based on bit compression technology. In 1989 he introduced the first working device based on a PC audio card using auditory masking: Audicom.
The psychoacoustic masking codec was first proposed in 1979, apparently independently, by Manfred Schroeder

The immediate predecessors of MP3 were “Optimum Coding in the Frequency Domain” (OCF), and Perceptual Transform Coding (PXFM). These two codecs, along with block-switching contributions from Thomson-Brandt, were merged into a codec called ASPEC, which was submitted to MPEG.

A working group took ideas from ASPEC, integrated the filter bank from Layer 2, added some of their own ideas and created MP3, which was designed to achieve the same quality at 128 kbit/s as MP2 at 192 kbit/s. All algorithms were approved in 1991 and finalized in 1992 as part of MPEG-1, the first standard suite by MPEG, which resulted in the international standard ISO/IEC 11172-3, published in 1993. Further work on MPEG audio was finalized in 1994 as part of the second suite of MPEG standards, MPEG-2, more formally known as international standard ISO/IEC 13818-3, originally published in 1995

Compression efficiency of encoders is typically defined by the bit rate, because compression ratio depends on the bit depth and sampling rate of the input signal. Karlheinz Brandenburg used a CD recording of Suzanne Vega’s song “Tom’s Diner” to assess and refine the MP3 compression algorithm.} This song was chosen because of its nearly monophonic nature and wide spectral content, making it easier to hear imperfections in the compression format during playbacks. Some jokingly refer to Suzanne Vega as “The mother of MP3″. Some more critical audio excerpts (glockenspiel, triangle, accordion, etc.) were taken from the EBU V3/SQAM reference compact disc and have been used by professional sound engineers to assess the subjective quality of the MPEG Audio formats. It is important to understand that Suzanne Vega is recorded in an interesting fashion that results in substantial difficulties that arise due to Binaural Masking Level Depression (BMLD) as discussed in Brian C. J. Moore’s book on the Psychology of Human Hearing, for instance.