An improved stereophonic coding scheme compatible to the ISO/MPEG audio coding algorithm

Stereophonic coding has been applied to the ISO/MPEG audio coding algorithm to improve the quality of stereo signals at very low bit rates. While reasonable quality has been achieved at bit rates of 2×64 kbit/s or lower, it was found that the proposed scheme could not achieve consistent good quality sounds for all types of audio signals. An improved stereophonic coding scheme is presented. This improved scheme employs the use of error minimisation and power equalization to obtain the improvements. Simulations of the scheme at a bit rate of 128 kbit per stereophonic channel produced a significant improvement in the quality of the audio over the original scheme. A quality that is close to transparency can be obtained at a bit rate of 128 kbit/s