The study aims to identify the spectral characteristics of accented Russian speech of bilinguals, native speakers of Karachay-Balkar, that possess sufficient identification significance. The paper presents an experimental study of interlinguistic interference and accent in the Russian speech of bilinguals (L1 – Karachay-Balkar, L2 – Russian). For conducting primary statistical analysis, spectral characteristics of allophones of six stressed Russian vowels [a], [o], [u], [e], [i] (и, ы) were measured. The values of the first two formants of the allophones under consideration were assessed using Praat and compared with the corresponding acoustic parameters of the same vowels in normative Russian speech. The study is novel in that it is the first one to conduct a quantitative assessment of systematic pronunciation errors in the spoken language of native speakers of Karachay-Balkar involving factual linguistic material. The results of statistical analysis of the source data demonstrated the possibility of reliably identifying accented Russian speech of L2 speakers, native speakers of Karachay-Balkar.