From the early pulse code modulation-based coders to some of the recent multi-rate wideband
speech coding standards the area of speech coding made several significant strides with an
objective to attain high quality of speech at the lowest possible bit rate. This book presents
some of the recent advances in linear prediction (LP)-based speech analysis that employ
perceptual models for narrow- and wide-band speech coding. The LP analysis-synthesis framework
has been successful for speech coding because it fits well the source-system paradigm for
speech synthesis. Limitations associated with the conventional LP have been studied extensively
and several extensions to LP-based analysis-synthesis have been proposed e.g. the discrete
all-pole modeling the perceptual LP the warped LP the LP with modified filter structures
the IIR-based pure LP all-pole modeling using the weighted-sum of LSP polynomials the LP for
low frequency emphasis and the cascade-form LP. These extensions can be classified as
algorithms that either attempt to improve the LP spectral envelope fitting performance or embed
perceptual models in the LP. The first half of the book reviews some of the recent developments
in predictive modeling of speech with the help of Matlab(TM) Simulation examples. Advantages of
integrating perceptual models in low bit rate speech coding depend on the accuracy of these
models to mimic the human performance and more importantly on the achievable coding gains and
computational overhead associated with these physiological models. Methods that exploit the
masking properties of the human ear in speech coding standards even today are largely based
on concepts introduced by Schroeder and Atal in 1979. For example a simple approach employed
in speech coding standards is to use a perceptual weighting filter to shape the quantization
noise according to the masking properties of the human ear. The second half of the book reviews
some of the recent developments in perceptual modeling of speech (e.g. masking threshold
psychoacoustic models auditory excitation pattern and loudness) with the help of Matlab(TM)
simulations. Supplementary material including Matlab(TM) programs and simulation examples
presented in this book can also be accessed here. Table of Contents: Introduction Predictive
Modeling of Speech Perceptual Modeling of Speech
