Fundamentals of Speech Recognition

Speech recognition has been an active research area for many years. It is not until recently, over the past 2 years or so, the technology has passed the usability bar for many real-world applications under most realistic acoustic environments (Yu and Deng, 2014). Speech recognition technology has started to change the way we live and work and has became one of the primary means for humans to interact with mobile devices (e.g., Siri, Google Now, and Cortana). The arrival of this new trend is attributed to the significant progress made in a number of areas. First, Moore’s law continues to dramatically increase computing power, which, through multi-core processors, general purpose graphical processing units, and clusters, is nowadays several orders of magnitude higher than that available only a decade ago (Baker et al., 2009a,b; Yu and Deng, 2014).