Issues and Limitations of HMM in Speech Processing: A Survey

Speech is the most natural way of communication among humans. This mode of communication is constituted of two parts, namely sound and sense. The intelligent production and synthesis of speech has intrigued man himself for long and efforts at automated speech recognition, has gone through various phases. Hidden Markov Models (HMMs) provide a simple and effective framework for modeling time-varying spectral vector sequences. Application of HMMs to speech recognition has seen considerable success and gained much popularity. As a consequence, almost all present day speech recognition systems are based on HMMs.