Critical band quantisation analysis for masked distortion speech coding

This paper presents new results on critical band masked distortion controlled quantisation of a linear transform representation of speech. In particular, fixed rate split vector quantisation of a critical band gain vector is investigated. While shown to be objectively significant in meeting masked distortion criteria, near-transparent quantisation of the critical band gain spectrum is nonetheless achieved at 1.75 kbits/sec. The relevance of this result is explained by a comparative interpretation of the parametric spectral synthesis performed by current analysis-by-synthesis, multi-band excitation and sinusoidal transform coders.