Igor Dobrodomov’s idea about the umlaut transformation of old Russian vowel phonemes ě and e

The article deals with a systematic approach to the study of the history of the Old Russian vowel phonemes ě and e. It is considered from the standpoint of the umlaut transformation idea, expressed by Igor Dobrodomov (1935-2022), professor of the Moscow Pedagogical State University. This leads to a new understanding of some historical and phonetic processes in Russian vocalism, in particular in the front row and middle rise zones. It is claimed that in the Russian language the old phoneme has disappeared, and the old phoneme has been preserved. The phoneme has been quantifiably and qualitatively strengthened due to the defonologization of the phoneme e.