OF MACHINES BY VOICE IN THE FORM OF ISOLATED OR CONNECTED WORD SEQUENCES. IT INVOLVES THE RECOGNITION AND UNDERSTANDING OF SPOKEN LANGUAGE BY MACHINE. SPEECH RECOGNITION IS A TECHNOLOGY THAT ABLE A COMPUTER TO CAPTURE THE WORDS SPOKEN BY A HUMAN WITH A HELP OF MICROPHONE. IT EVALUATE THE PERFORMANCE OF DIFFERENT TECHNIQUES MEL FREQUENCY CEPSTRAL COEFFICIENTS (MFCC),PERCEPTUAL LINEAR PREDICITION COEFFICIENTS(PLP),AND PERCEPTUAL LINEAR COEFFICIENTS(PLC).