Automatic Speech Recognition: A Review

This paper attempts to describe a literature review of Automatic Speech Recognition. It discusses past years advances made so as to provide progress that has been accomplished in this area of research. One of the important challenges for researchers is ASR accuracy. The Speech recognition System focuses on difficulties with ASR, basic building blocks of speech processing, feature extraction, speech recognition and performance evaluation. The main objective of the review paper is to bring to light the progress made for ASRs of different languages and the technological viewpoint of ASR in different countries and to compare and contrast the techniques used in various stages of Speech recognition and identify research topic in this challenging field. We are not presenting exhaustive descriptions of systems or mathematical formulations but rather, we are presenting distinctive and novel features of selected systems and their relative merits and demerits.