The article is devoted to the description of the vocal systems of different languages, considering the functional approach, based on the objective linguistic reality. Today the traditional approach used by research scientists is gradually losing the ability to identify effective models of the phonetic-phonological system of the language, which significantly affects the productivity and research results. The rapid development of new directions of science, the evolution of the language system and all its sublevels indicates the need to adjust the traditional principles of describing phonetic-phonological systems of different languages and imposes special requirements on the relevance, productivity, adequacy and compliance of such descriptions with objective reality. The article analyzes the system of vowels from a phonological point of view — a general classification of vowels through the prism of phonological systematics of meaningful oppositions — considering the articulatory base of the language and the modern orthoepic norm, their changes in the flow of speech, an inextricable connection with consonantism and the prosodic organization of the word. This system is more productive and relevant for solving the problems of modern linguistics. The approbation of the vocal system of the Russian language, obtained within the framework of the corrected approach to the description of systems, is carried out in conditions of language contact, since the problems of language contact are interconnected with the main tasks of the theory of language in the framework of the comparative historical description and comparison of languages. Phonetic interference, together with a foreign accent, is a consequence of the contact between the native language and the target language. Phonetic interference, being an integral part of linguistic contact, causes a violation of the sound side of the language of foreigners. After analyzing the descriptions of the vocal systems of the Spanish and Russian languages, made within the framework of the adjusted functional approach, it is possible to highlight the main features of the Spanish accent in the pronunciation of Russian vowel sounds, and the analysis of the practical material confirms all the selected features and demonstrates the high efficiency of the above approach. The results of this work can be used in various theoretical courses, as well as to create systems for automatic synthesis and speech recognition. © 2021, RUDN UNiversity. All rights reserved.