Comparison of Two Different Approaches to Detect Perceptual Noise for MPEG-4 AAC

The MPEG-4 AAC introduces a new tool called Perceptual Noise Substitution (PNS) whose function is to use locally generated noise to replace the noise inside the coded music. The key issue to the PNS tool relies on the correctly detect the perceptual noise. In this paper, we point out the potential problem of the approach suggested in the ISO’s document and compare it with the other approach, proposed by the original contributors of the PNS concept, and discuss their relative performance.