The vowel “[ǝ]-muet”, specific of French because its instable aspect, requires a special attention. The instability of the “E-muet” emerges on different levels. On the one hand, the question of the acoustic nature of this vowel is not definitely resolved. On the other hand, the segment [ǝ] can be pronounced or not in the same unit of speech according to the multiple factors. The research of distribution of the “E-muet” and its phonetic features are important for those who want to know its characteristics in a didactic perspective. This article presents the features of changing some of the acoustic characteristics of the segment [ǝ] in regional variations of the French language. The experimental material includs sound samples from the inhabitants of the northern and southern regions of France, as well as French-speaking residents of Belgium, Switzerland and Canada. Using methods of auditory and instrumental analysis, we studied the frequency of emergence of the vowel [ǝ], as well as its duration and formant structure. The reliability of the findings is ensured by statistical processing of the data.