I've seen a lot of books on Speech processing, but this one's the best by quite some margin. Rabiner & Schafer's classic could've edged this one out, but it's slightly dated now(1978 was a long time ago!) - it remains a great source for the fundamentals, though. However, this book is uptodate, as well as quite exhaustive in its coverage of the basics. One can get a solid grasp of basic speech processing(eg pitch analysis), synthesis, compression and recognition. The chapters on recognition, especially, are quite impressive,with detailed treatment of all the standard techniques in the field,including Dynamic time warping,Hidden Markov models & Neural networks. Everything from isolated word recognition to large vocabulary continuous speech recognition is touched upon.
This book is an ideal starting point for exploring the world of speech processing,which is a very rich area of research and has virtually limitless commercial applications,too.
A word of caution though - this is not for the layman.One requires a bit of a background in mathematics,and a little knowledge of digital signal processing won't hurt either.
I have only nice things to say about this book.The only possible crib could be the hefty price tag,but then this is typical of books in this field.
All in all,it's an excellent textbook,which ought to be read by everyone working in speech processing.