This paper describes method and results of experimental investigation on the domain of acoustical analysis of a spoken text especially for differences between acoustic parameters of a set of words with pauses and without ones. The aim of investigation was a comparison between separate isolated pronounced words and the same words in a speech flow in text for Russian language. The present study was aimed also at revealing the differences between the prosodic features ( such as the fundamental frequency, intensity, duration) of isolated words vs. the same words in speed, (in text). Acoustical analysis has revealed that for a number of parameters there are regular differences between the separately pronounced words and the same words in the pause-free connected speech. The results were used as a part of linguistic information in recognition system.