Resumo: This thesis presents an analysis of intraspeaker prosodic variation in newscasting speech, a relevant topic for the development of sociophonetic analyses with potential forensic applications. Through the systematic acoustic analyses of a 19 year speech sample of a middle-aged Brazilian journalist, this research sought to investigate the behaviour of intonational, vocal quality, and intensity parameters in this instance of non-vernacular speech. Moreover, the research also investigates the correlation of news themes and content valence on the analysed prosodic parameters. Each audio sample was manually classified in regard to its theme and its content valence. All the acoustic parameters were extracted via Praat and statistical analyses were done using the R programming language. Results showed an overall great variability in most of the prosodic measures between the sampled news editions. There was an observable trend of change in some of fundamental frequency parameters, going towards a lower pitch and a less dynamic speech. In addition, these results highlight age-related changes in vocal behaviour and vocal characteristics before senescence, even in the case of a speaker subjected to vocal training and long-term speech therapy. The comparison between the themes suggests that some news subjects follow similar acoustic patterns, tending towards a more dynamic vocal behaviour. On the other hand, the greatest differences in vocal behaviour were observed in a specific set of news in which the anchor clearly displayed sadness. The valence of the utterances showed a low correlation with the acoustic parameters. The findings of this research highlight the importance of social factors in forensic phonetics practices, indicating the relevance of adopting a sociophonetic approach to forensic linguistics. Furthermore, the parameters reported here may serve as a reference for further forensic analysis, given that there is little data regarding intraspeaker prosodic variation in non-vernacular speech.

Palavras-chave: Sociophonetics; Forensic phonetics; Prosody (Linguistics); Language variation; Aging