| Dear Massimo Grassi, As Matthias said, you can have a look at the book "Audio Signal Processing and Coding" by Spanias. In chapter 5, there's an outline about psychoacoustics and its application to mp3. This application is in section 5.7 (EXAMPLE CODEC PERCEPTUAL MODEL: ISO/IEC 11172-3 (MPEG - 1) PSYCHOACOUSTIC MODEL 1). There are many tutorials about mp3, but one very easy to read is Davis Pan's "A tutorial on MPEG/Audio Compression". It also shows graphically the advantage of the mp3 technique. Please note that MP3 takes advantage of the spectral and temporal masking of the input data. The former is used for reducing the output bit rate. Temporal masking is used for minimizing the error introduced by the filter bank. For further questions, please do not hesitate in asking me. Regards, Fernando PS: DOES ANYONE IN THIS LIST RECOMMEND AN AUDIO CODING FORUM? Dr. Fernando A. Marengo Rodriguez Acoustics and Electroacoustics Laboratory National University of Rosario Rosario, Argentina http://www.fceia.unr.edu.ar/acustica/ |