Unfamiliar voice identification: effect of post-event information on accuracy and voice ratings

This study addressed the effect of misleading post-event information (PEI) on voice ratings, identification accuracy, and confidence, as well as the link between verbal recall and accuracy. Participants listened to a dialogue between male and female targets, then read misleading information about voice pitch. Participants engaged in verbal recall, rated voices on a feature checklist, and made a lineup decision. Accuracy rates were low, especially on target-absent lineups. Confidence and accuracy were unrelated, but the number of facts recalled about the voice predicted later lineup accuracy. There was a main effect of misinformation on ratings of target voice pitch, but there was no effect on identification accuracy or confidence ratings. As voice lineup evidence from earwitnesses is used in courts, the findings have potential applied relevance

Speaker Sex Perception from Spontaneous and Volitional Nonverbal Vocalizations.

In two experiments, we explore how speaker sex recognition is affected by vocal flexibility, introduced by volitional and spontaneous vocalizations. In Experiment 1, participants judged speaker sex from two spontaneous vocalizations, laughter and crying, and volitionally produced vowels. Striking effects of speaker sex emerged: For male vocalizations, listeners' performance was significantly impaired for spontaneous vocalizations (laughter and crying) compared to a volitional baseline (repeated vowels), a pattern that was also reflected in longer reaction times for spontaneous vocalizations. Further, performance was less accurate for laughter than crying. For female vocalizations, a different pattern emerged. In Experiment 2, we largely replicated the findings of Experiment 1 using spontaneous laughter, volitional laughter and (volitional) vowels: here, performance for male vocalizations was impaired for spontaneous laughter compared to both volitional laughter and vowels, providing further evidence that differences in volitional control over vocal production may modulate our ability to accurately perceive speaker sex from vocal signals. For both experiments, acoustic analyses showed relationships between stimulus fundamental frequency (F0) and the participants' responses. The higher the F0 of a vocal signal, the more likely listeners were to perceive a vocalization as being produced by a female speaker, an effect that was more pronounced for vocalizations produced by males. We discuss the results in terms of the availability of salient acoustic cues across different vocalizations

Earwitnesses: effects of accent, retention and telephone

Contains fulltext : 54671.pdf (publisher's version ) (Closed access)An experiment was conducted to investigate the effects of accent, telephone and a relatively long retention interval (3 or 8 weeks) on speaker identification. Three-hundred and sixty participants heard the target's voice and were asked to identify the target by means of a line-up consisting of 6 voices. Half of the participants were given a target-present line-up and the other half a target-absent line-up. The results showed that 24% of participants correctly identified the target in the target-present condition (hits), whereas 50% of participants incorrectly identified a person as the target in the target-absent condition (false alarms). The speaker with the standard-accented voice was more often correctly recognized than the speaker with the non-standard-accented voice. No difference was found between identification accuracy after one, three or eight weeks and between the telephone and non-telephone conditions. It can be concluded that there is a relatively high probability that an innocent defendant is identified as the perpetrator, even in a procedurally correct voice line-up (in this experiment 8%). Furthermore, reliability may be drastically reduced when the perpetrator has a strong accent, unfamiliar to the listener. On the other hand, reliability of a voice line-up seems not to be affected by a presentation over the telephone, as well as by a retention interval of at least 8 weeks.12 p

Interference in eyewitness and earwitness recognition

Face identification and voice identification were examined using a standard old/new recognition task in order to see whether seeing and hearing the target interfered with subsequent recognition. Participants studied either visual or audiovisual stimuli prior to a face recognition test, and studied either audio or audiovisual stimuli prior to a voice recognition test. Analysis of recognition performance revealed a greater ability to recognise faces than voices. More importantly, faces accompanying voices at study interfered with subsequent voice identification but voices accompanying faces at study did not interfere with subsequent face identification. These results are similar to those obtained in previous research using a lineup methodology, and are discussed with respect tothe interference that can result when earwitnesses are also eyewitnesses