The influence of style-shifting on voice identification

Abstract

Alterations in speaking style, and associated problems, are commonly found in criminal investigations. Typically, the recorded samples have been made in two different environments; during the crime and then during police questioning. These inherent differences in situation, lead to the possibility that the style of speech also is changed. This project was developed to evaluate one of the problems that results, that is, the influence of code-switching on speaker identification. To this end, voice samples representing casual, extemporaneous and formal conditions were elicited from five African-American males and presented to naive listeners in a paired comparison listening task of speaker recognition. It was found that the type of speaker's utterance had a significant impact on the identification judgements. That is, if an individual was represented by two different styles of speech, they were more likely to be identified as different people than if they were compared within the same condition. Hence, it can be concluded that code-switching, as induced by changes in the social situation and recording environment, may result in the misidentification of a particular speaker.