Incorporation of biorthogonality into lapped transforms for audio compression

Acoustic signal representations used in current audio coding algorithms can be improved by the incorporation of biorthogonality into Malvar´s extended lapped transform (ELT). Biorthogonality allows more flexibility in the design of the analysis and synthesis windows by increasing the number of degrees of freedom. This paper examines this increase for two special cases and demonstrates the importance of the additional flexibility to the proper implementation of psychoacoustic modeling, a feature central to all modern audio compression schemes