This paper describes some of differences between the prosodic characteristics such as the fundamental frequency (F0), intensity (I), duration (t) of isolated words vs. the same words in connected speech (phrases, sentences, texts). Ten native speakers of Russia of Moscow pronouncing orthoepic norm contributed to this study. It was of great interest to study the correlation between the acoustic characteristics of isolated and non-isolated words. The solution of this problem will make it easier to obtain necessary information about the acoustic features of speech flow and to formulate the rules of expert-systems on the domain of automatic speech recognition and speech synthesis.