Changes in the Spectral Characteristics of Vowels in Russian Speech on a Noise Background

Abstract

The article studies the acoustic characteristics of Russian speech under conditions of multitalker babble noise and manifestation of the Lombard effect in the context of auditory analysis of a complex scene. We have compared the spectral characteristics of stressed vowels [a], [u], [i] in words uttered by six women in completely quiet conditions and against a background of diotically presented multitalker babble noise at a level of 60 dB, imitating polyphony. In noise conditions, versus quiet, we obtained an increase in voice fundamental frequency (F0) and the first formant (F1) for all identified vowels. No overall pattern in changes in the second formant (F2) was found. When the vowel [i] was spoken in noise conditions, F2 decreased in all speakers; when vowels [u] and [a] were pronounced, it could have both decreased and increased. Thus, in general, the nature of the revealed changes in the spectral characteristics of the vowels of Russian speech in noise conditions corresponded to the features of Lombard speech for a number of European and Asian languages. For the first time, an inversely proportional relationship between F0 of a speaker in quiet conditions and its changes in noise conditions: the higher F0 in quiet conditions, the less its increase on a noise background . The revealed spectral changes reflect the processes of adaptive articulation correction aimed at highlighting the speaker’s voice and increasing the intelligibility of his speech against the background of multitalker babble noise.