Bilingualism as a ubiquitous phenomenon in modern society requires more detailed research in order to better understand the phenomenon itself and the characteristics of the language of bilingual people. An increasing number of children are learning two languages at the same time from birth or with a certain time interval. Thanks to research in the field of bilingualism, we get a clearer picture of the potential advantages and disadvantages that arise with this phenomenon. Code-switching is also an important and the most recognizable feature of a bilingual person's speech. It involves switching from one language to another during communication. Since the activation of both languages of a bilingual person is stronger during this time, it is very important to research these phenomena to better understand the characteristics of bilingual speech and the changes that occur during that time. Phonetic code-switching studies so far have been largely based on the study of changes in VOT length in the speech of bilingual individuals. The results of these studies proved the existence of changes in pronunciation during codeswitching. The aim of this paper is to present and compare these researches.