Rounding of unstressed vowels in Russian

A certain type of rounding vowel “harmony” occurs in Russian when an unstressed allophone of an unrounded phoneme is pronounced as rounded before an unstressed rounded phone in a pretonic part of the word. A similar “harmony” is observed in the post-tonic part as well. This phenomenon may have an impact on the phonological system of the Russian language in the future. An experimental study was carried out to determine what contextual, combinatorial and suprasegmental factors aff ect the process of rounding, what kind of articulation occurs in these cases. The technology of electromagnetic articulography together with acoustic analysis of the speech signal was used as an experimental method. The experiments were based on reading specially prepared phrases accounting for various linguistic factors that could potentially aff ect assimilative rounding. The analysis of data on distant vowel coarticulation shows that when a vowel /u/ is pronounced in an unstressed position the lips begin to move in advance, which aff ects both consonants and unstressed vowels pronounced before it. It results in coarticulation of unstressed vowels, while non-labial consonants between the vowels have practically no eff ect on this process. Our results show that the first and the second degrees of reduction of the vowel /a/ diff er in articulatory resistance to the influence of rounded vowels, namely that the allophone of the fi rst degree of reduction, unlike that of the second degree of reduction, is not assimilated as a result of the coarticulation movement that occurs when pronouncing subsequent /u/. The anticipatory rounding may be up to three syllables long and go across word boundaries.