The Impact of Laughter in Earwitness Identification Performance

This study examines whether voice identification performance is influenced whilst processing voice identity information by the presence of non-verbal vocalizations such as laughter. Ninety-six participants were exposed to an auditory event of 45 seconds in length presenting verbal and non-verbal information, including laughter. After a delay of 5 minutes, participants took part in a voice line-up manipulated for laughter (speech only, laughter only, or speech and laughter) and target presence (target present or target absent). Supporting the first hypothesis, participants' performance was significantly worse in the speech alone condition compared with both laughter conditions (laughter alone and laughter with speech). Further, identification performance was best in the laughter only condition. In addition, participants correctly rejected the line-up significantly more in the speech and laughter condition than in the speech alone or laughter alone conditions. Findings are discussed in terms of their implications for real-life earwitness identification parades.