A complete issue of IEEE Signal Processing Magazine. Although a few years old, this is still a very useful survey of current techniques.
Sadaoki Furui, Li Deng, Mark Gales, Hermann Ney and Keiichi Tokuda (Guest Editors). “Fundamental Technologies in Modern Speech Recognition“, 2012. In IEEE Signal Processing Magazine 29(6)
The link is to the editors’ introduction, but you should look at all the articles in this issues.
