Aspects of investigation of Northwest Russian dialects (instrumental phonetic study of the vowel system in one idiolect)

The article presents the results of a study of Russian dialects of the island Pijrissaar (Estonia). The collected material contributes to the solution to some  problems of the evolution of pretonic vocalism systems in Northwest Russian dialects. The example of incomplete okanye of the Polnovskij type shows that the sequence of complete okanye → incomplete okanye → akanye is closely linked to changes in the prosodic organization of words that occur in these dialects.