An experimental investigation is presented that observes the influence of expertise in speaking, the content of speech and audiovisual perception on the formation of impressions of media speakers in the context of Spanish communication. After perceiving each speaker, the subjects answered a questionnaire containing semantic differential questions. The results of the statistical tests provided useful information for the understanding of the process of understanding audiovisual speech, of the formation of impressions, and of factors influencing the audio-visual interpretation of non-improvised messages by the audiences of media communication contexts (i.e. radio and television). The data provided by the experiment is fundamentally interpreted in relation to the language expectancy theory, which explains, and predicts, the attitude that audiences have to the acts of speech.