In the conditions of natural Mari-Russian bilingualism Mari students studying French at the faculty of foreign languages of MARSU need to learn articulation base of this foreign language for the purpose of its further teaching. At the same time, learning proper French pronunciation is complicated because of influence of native (Mari) language. In the conditions of the same artificial bilingualism, the comparative phonetic analysis is of great importance. Comparison of two language systems is important for the solution of questions of universality and uniqueness of the language phenomena. When researching problems related to bilingualism, it is necessary to take into account the processes and factors that contribute to the appearance of interference. It is considered that the less there is typological distance between native and studied languages, the more degree of their similarity and the less distinction, the more there are possibilities of interference. If this distance is big, that is the languages are genetically unrelated as, for example, French and Mari, then, therefore, there will be less mistakes and cases of automatic hyphenation. The real image of phonetic violations in speech of bilinguals can differ considerably from predicted ones. At the same time, experimental and phonetic researches of Mari students’ speech studying French receive great significance. Data of the comparative analysis help to find and explain the reasons of certain distortion. Therefore comparison at the segmental level has to be based on acoustic characteristics of sounds and their differential features; and comparison at the suprasegmental level is on the description of melodic contours. All current phonological schools have laboratories of the experimental phonetics based on application of modern phonetic methods of speech research. These methods are rather various: oscillographic, gistographic, intonographic. Methods of instrumental analysis are complemented with acoustic, statistical, theoretical and linguistic methods. The problem of language interaction in the modern world has gained practical importance: comparative phonetic analysis of phoneme system of two languages is useful for Mari students studying French in bilingualism conditions.