This paper gives a comprehensive introduction about speech production and perception in Human beings, discusses the challenges and applications, frame work of Automatic Speech Recognition(ASR) systems, and provides the detailed description about the architecture of ASR. The paper highlights the problem de nition, general objectives, scope of ASR research. The work provides meticulous review about the baseline ASR systems and indicates the need for research in ASR. A methodical way of designing a speech corpus for Indian languages is presented in this paper. Finally wavelet based Thresholding techniques are utilized to process the designed speech corpus. The experiments are carried out on the Kannada speech corpus consisting of continuous sentences and results are compared with those obtained on the bench marking TIMIT dataset. The results convey that the Proposed method performs better for both the databases for various SNR conditions.