Abstract: The Russian voiced obstruent consonants [v] and [v'] have different effects on determining strong and weak voiced-unvoiced positions for preceding obstruent consonants. The position before these sounds can be either weak or strong - it all depends on the class of sounds following [v] and [v'], which can be characterized as their "transparency". The position is strong if they are followed by a vowel. In such cases there is no voicing of the preceding deaf; the consonants are distinguished by voiced-unvoiced. In this respect [v] and [v'] are phonologically similar to sonorants. The position is weak if [v] and [v'] are followed by a obstruent consonant. If it is an unvoiced obstruent, there is a deafening of the [v] sound. If it is a voiced obstruent, then assimilation by voicing takes place. It is in this case that the property of "transparency" of the sound [v] is manifested, as this sound becomes "invisible", i.e. "transparent" for the processes of voiced-unvoiced assimilation. This study was conducted using the Praat phonetic program for the analysis of sounding speech. The methodological choice is conditioned by the nature of the study. There are scientific articles concerning the "transparency" of the [v] sound, but they have no detailed experimental analysis. This paper presents the results of a phonetic experiment of the realization of the consonant [v] in the combinations "unvoiced obstruent + [v] + voiced obstruent". The main conclusions in the present article are the confirmation of distant regressive assimilation by voiced-unvoiced in the sounding speech of modern speakers of Russian. The results obtained in the course of the study prove that in modern Russian literary language a stable voicing of deaf obstruent consonants in the combinations "unvoiced obstruent + [v] + voiced obstruent" is preserved.

Keywords: phoneme realization, phonology, transparency of the voiced bilabial, transparency of sounds, sound, assimilation, dynamics of the orthoepic norm, sounding speech, phonetics, Russian language