The system of French accentuation is a relevant case of a language change, observable in a relatively short period of time in a stable synchrony. Since the mid-twentieth century, the formation of linguistic norms has largely depended on a specific type of utterance, media discourse, continually available in spoken audio-visual media. The impact of spoken media on the development of linguistic expression in the last few decades is unprecedented in language history. It is based on a communicational model in which speech is produced by a single speaker and instantly perceived by a multitude of receivers who have no possibility of intervening in the communicational process. Thus the receivers are passively exposed to an exclusive speaker and to language strategies conceived by the media and its linguistic authority. The analysis of two professional spoken interventions, uttered on French television, shows an important modification of the traditional accentual system: conserving the final accent (FA), the speakers systematically introduce an initial accent (IA), a landmark in the evolution of the French language and its normative features. The IA affects the first syllable of a stressed lexeme or the first syllable of an extended accentual unit, regardless of the syntactic function of the stressed morpheme. The FA is operated by the intonational action, while the IA seems to be realized by an accentual augmentation of vocal intensity. The automatism of lexical stressing is generating a systematic accentuation of the first syllable of the accentual unit. The IA mostly affects lexemes that speakers insist on because of their informative value (numerals, adverbs, proper names), but an important part of IA concerns different proclytics, such as deictic elements, articles and determinants. Accentual limitation of the unit on both sides is a specific feature of the speech in French audio-visual media. In recent decades it has found its echo in the normative speech of French linguistic communities.