Earwitness Identification Research Articles

Evaluating earwitness identification procedures: adapting pre-parade instructions and parade procedure

ABSTRACT Voice identification parades can be unreliable, as earwitness responses are error-prone. In this paper we tested performance across serial and sequential procedures, and varied pre-parade instructions, with the aim of reducing errors. The participants heard a target voice and later attempted to identify it from a parade. In Experiment 1 they were either warned that the target may or may not be present (standard warning) or encouraged to consider responding “not present” because of the associated risk of a wrongful conviction (strong warning). Strong warnings prompted a conservative criterion shift, with participants less likely to make a positive identification regardless of whether the target was present. In contrast to previous findings, we found no statistically reliable difference in accuracy between serial and sequential parades. Experiment 2 ruled out a potential confound in Experiment 1. Taken together, our results suggest that adapting pre-parade instructions provides a simple way of reducing the risk of false identifications.

Voice Identification Experts

This article examines United States v. Schiro, 679 F.3d 521 (7th Cir. 2012) and the issue of reliability of voice identification or earwitness identification. Given that mistaken eyewitness identification is a major contributor to wrongful convictions, courts should instruct jurors of the frequency of voice identification mistakes. In addition, jurors should be educated as to factors that promote or detract from accuracy. Jurors should be instructed to examine identification testimony carefully.

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.

Earwitnesses: the effect of type of vocal differences on correct identification and confidence accuracy

Individual voice and speech characteristics are important for earwitness identification. A target-absent line-up with six foils was used to analyse the influence of voice and speech features on recognition. To create ecologically valid conditions for voice recognition, the present study used voices in conversation in the target event and for the foils. The participants were particularly successful in rejecting the two voice foils that were most dissimilar to the target voice in articulation rate and pitch. These two foils were also given somewhat higher confidence judgments than the other foils, although the level of that confidence was still somewhat low. In fact, participants as a collective were underconfident for these two foils but were overconfident for the other foils. In addition, they showed somewhat better ability in their confidence judgments to distinguish correct and incorrect responses for the two most dissimilar foils than for the four foils for which their identification responses were less successful. For the other four foils, which were more similar to the target voice, the participants showed in their confidence judgments very poor ability to distinguish between correct and incorrect identifications. Later positions in the parade were more often (erroneously) identified as the culprit, regardless of the specific foils used in those positions.

Earwitness identification performance: the effect of language, target, deliberate strategies and indirect measures

AbstractThe present study examined whether voice identification performance is influenced by language comprehension (i.e. familiar vs. non‐familiar language) and target presence (target‐present (TP) vs. target‐absent line‐ups (TA)). It also looked at the relationship of deliberate strategies and indirect measures (i.e. confidence, difficulty and pressure) with performance. Sixty Native English speakers were exposed to an auditory event involving 45 to 50 seconds of speech. After 30 minutes delay, participants listened to a voice line‐up (TP or TA) in either a familiar (i.e. English) or unfamiliar language (i.e. French) according to the language spoken during the event, and were then asked to identify the original speaker's voice. Participants demonstrated significantly better performance for the familiar language/TP line‐ups. Participants who reported using the ‘elimination’ strategy were significantly more accurate than participants who reported using either a ‘matching’ strategy or no strategy. Indirect measures were not found to be good predictors of performance, except for confidence regarding TA accuracy. Copyright © 2006 John Wiley & Sons, Ltd.

Lay people's and police officers' attitudes towards the usefulness of perpetrator voice identification

AbstractExpert and lay knowledge of factors that affect the identification of a voice is an area of research that is still relatively unexplored. Much more research has focused on eyewitness identification and eyewitnesses' common knowledge. However, results from ‘eyewitnessing’ studies may not be directly applicable to ‘earwitnessing’. The present study examines how knowledgeable British lay people and police officers were concerning earwitness identification performance. One hundred nine participants (i.e. 49 lay people and 60 police officers) responded to a specially designed questionnaire. Results showed respondents to be more knowledgeable than expected, although police officers were no more knowledgeable than the general population. The existence of meta‐knowledge is discussed in relation to previous studies. Copyright © 2006 John Wiley & Sons, Ltd.

Earwitness identification over the telephone and in field settings

Earwitnesses were asked to describe and identify the voice of a young woman to whom they had spoken approximately five minutes earlier either in a naturalistic field setting or over the telephone. Witnesses were given a single tape-recorded voice of either the target or a highly similar foil, or a target present or a target absent six-person voice line-up. Half of the witnesses in the naturalistic settings were given a photograph of the target as a retrieval cue when they attempted to describe and identify the voice of the target. Witnesses gave few descriptions of the speaker’s voice. Voice identification was poor in both types of setting. Those witnesses who were prepared for a memory test were superior to non-prepared witnesses on the subsequent identification test. Photographic retrieval cues did not influence voice descriptions, but did minimize false identifications on the target absent line-up for witnesses prepared for the test. The six-person line-up proved to be significantly superior to the one-person lineup in minimizing false identifications of the most highly similar sounding foil.

Arranging a voice line-up in a foreign language

Speaker identification by lay witnesses is an area that is still relatively unexplored. The volume of empirical research in this field contrasts sharply and unfavourably with the wealth of work reported in the literature on human identification in the visual domain. Nor is it clear that the findings of eyewitness research are sufficiently well known in forensic phonetic circles, in spite of their patent relevance to earwitness identification. Many of the issues over which consensus has been reached among those working in the field of eyewitness identification (Wells et al. 1998) continue to be unresolved in the forensic speaker identification community. Attempts to take matters further by taking on board the unquestioned insights gained in the visual field have so far met with a lukewarm reaction at best. After a promising start (Hollien et al. 1995, Broeders 1996, Hollien 1996), little progress has been made in recent years within either IAFP (the International Association for Forensic Phonetics) or the ENFSI (European Network of Forensic Science Institutes) Expert Working Group for Forensic Speech and Audio Analysis in formulating generally accepted procedures for the conduct of voice line-ups. At the same time, debate seems to have come to a virtual standstill, as witness the lack of response to the most recently proposed set of guidelines (Broeders and Van Amelsvoort 1999). Yet, ever since McGehee’s (1937) work following the Lindbergh trial, the need to develop proper procedures in the conduct of earwitness identification has been abundantly clear.

Arranging a voice lineup in a foreign language

Speaker identification by lay witnesses is an area that is still relatively unexplored. The volume of empirical research in this field contrasts sharply and unfavourably with the wealth of work reported in the literature on human identification in the visual domain. Nor is it clear that the findings of eyewitness research are sufficiently well known in forensic phonetic circles, in spite of their patent relevance to earwitness identification. Many of the issues over which consensus has been reached among those working in the field of eyewitness identification (Wells et al. 1998) continue to be unresolved in the forensic speaker identification community.
 
 Attempts to take matters further by taking on board the
 unquestioned insights gained in the visual field have so far met with a lukewarm reaction at best. After a promising start (Hollien et al. 1995, Broeders 1996, Hollien 1996), little progress has been made in recent years within either IAFP (the International Association for Forensic Phonetics)
 or the ENFSI (European Network of Forensic Science Institutes) Expert Working Group for Forensic Speech and Audio Analysis in formulating generally accepted procedures for the conduct of voice line-ups. At the same time, debate seems to have come to a virtual standstill, as witness
 the lack of response to the most recently proposed set of guidelines (Broeders and Van Amelsvoort 1999). Yet, ever since McGehee’s (1937) work following the Lindbergh trial, the need to develop proper procedures in the conduct of earwitness identification has been abundantly clear.

Speaker Identification Utilizing Noncontemporary Speech

The noncontemporariness of speech is important to both of the two general approaches to speaker identification. Ear-witness identification is one of them; in that instance, the time at which the identification is made is noncontemporary. A substantial amount of research has been carried out on this relationship and it now is well established that an auditor's memory for a voice decays sharply over time. It is the second approach to speaker identification which is of present interest. In this case, samples of a speaker's utterances are obtained at different points in time. For example, a threat call will be recorded and then sometime later (often very much later), a suspect' s exemplar recording will be obtained. In this instance, it is the speech samples that are noncontemporary and they are the materials that are subjected to some form of speaker identification. Prevailing opinion is that noncontemporary speech itself poses just as difficult a challenge to the identification process as does the listener's memory decay in earwitness identification. Accordingly, series of aural-perceptual speaker identification projects were carried out on noncontemporary speech: first, two with latencies of 4 and 8 weeks followed by 4 and 32 weeks plus two more with the pairs separated by 6 and 20 years. Mean correct noncontemporary identification initially dropped to 75-80% at week 4 and this general level was sustained for up to six years. It was only after 20 years had elapsed that a significant drop (to 33%) was noted. It can be concluded that a listener's competency in identifying noncontemporary speech samples will show only modest decay over rather substantial periods of time and, hence, this factor should have only a minimal negative effect on the speaker identification process.

Verification of impression of voice in relation to occupational categories.

The present study examined how personality traits, physical characteristics, and occupational categories derived from listening to human voices are related to each other. Stimuli were 25 tape-recorded male vocal samples. In Study 1, 114 undergraduate and graduate students rated each of the 25 voices on 22 personality traits and 11 vocal characteristics. Participants were also given a list of 34 occupational categories from which they selected one suitable occupational category for each of the 25 voices. Of 34 occupations, 20 occupations selected most frequently were used in Study 2 wherein 90 junior college students rated the voices on the 20 occupational categories. Factor analyses produced three factors for personality characteristics, for vocal characteristics, and for occupational categories. Also, significant correlations among those factors (both positive and negative) indicated participants consistently attributed particular personality and vocal characteristics to specific voices and assigned those voices to particular occupational categories. Stereotypical perception of voices is discussed in terms of earwitness identification.

Verification of Impression of Voice in Relation to Occupational Categories

The present study examined how personality traits, physical characteristics, and occupational categories derived from listening to human voices are related to each other. Stimuli were 25 tape-recorded male vocal samples. In Study 1, 114 undergraduate and graduate students rated each of the 25 voices on 22 personality traits and 11 vocal characteristics. Participants were also given a list of 34 occupational categories from which they selected one suitable, occupational category for each of the 25 voices. Of 34 occupations, 20 occupations selected most frequently were used in Study 2 wherein 90 junior college students rated the voices on the 20 occupational categories. Factor analyses produced three factors for personality characteristics, for vocal characteristics, and for occupational categories. Also, significant correlations among those factors (both positive and negative) indicated participants consistently attributed particular personality and vocal characteristics to specific voices and assigned those voices to particular occupational categories. Stereotypical perception of voices is discussed in terms of earwitness identification.

Earwitness recall and identification: comparison of the cognitive interview and the structured interview.

77 undergraduates instructed to act as kidnap victims heard taped instructions given by a mock abductor. Two days later witnesses' recall of the culprit's monologue was tested using either a Cognitive Interview or a Structured Interview. Participants then rated the abductor's voice for nine speech characteristics and attempted to identify his voice from an audiotaped lineup. No significant differences were found between the two interview conditions for accuracy or error rates in free recall, for ratings of descriptive voice characteristics, or for performance in voice identification. These earwitness results are consistent with eyewitness investigations which have yielded no positive influence of the cognitive interview on identification. It is concluded that the success of the cognitive interview is best explained through its influence on social components of interviewing.

Realism of confidence in earwitness versus eyewitness identification.

The confidence-accuracy relation in earwitness identification is studied with calibration and diagnosticity analysis. In comparison to eyewitness identification in similar circumstances (P. Juslin, N. Olsson, & A. Winman, 1996), earwitness accuracy is po

Realism of confidence in earwitness versus eyewitness identification.

Realism of confidence in earwitness versus eyewitness identification.

Consideration of guidelines for earwitness lineups

This presentation is part essay and part report. In the first instance, the responsibilities and challenges faced by forensic phoneticians who attempt to deal with the earwitness problem are addressed. The report, in turn, involves a description of the progress being made by a committee on earwitness identification which was appointed by the International Association of Forensic Phonetics in response to their obligations in this regard. The two will be combined here into a single effort.

Earwitness identification: common ground, disputed territory and uncharted areas

In the last decade there has been a growing interest in the questions raised by the auditory identification of persons by victims and witnesses. Within IAFP, the International Association for Forensic Phonetics, this has led to the call for guidelines or criteria for identification procedures such as the voice line-up. Against this background, parallels and contrasts with the more widely studied field of visual identification are discussed, as are a number of (un)resolved issues and/or misconceptions surrounding voice line-up procedure. These include the use of repeated trials, blank trials, familiar vs. unfamiliar voices, the use of actors, verbatim text or transcripts, and the notions of propitious heterogeneity and ecphoric similarity. Accepted notions are critically examined. The dearth of estimator-variable research is noted.

Earwitness identification: Some influences on voice recognition.

Earwitness identification: Some influences on voice recognition.

Earwitness identification: Some influences on voice recognition.

Earwitness identification: Some influences on voice recognition.

‘Earwitness’ voice recognition: Factors affecting accuracy and impact on jurors

AbstractTwo studies were conducted examining voice recognition testimony and its impact on jurors. In the first experiment, subjects listened to a tape recording of a brief sales pitch. After a retention interval of either 0, 7 or 14 days, subjects were unexpectedly asked to pick the salesperson's voice out of a five‐voice taped lineup. Retention interval did not have a significant effect on hit rates or false alarms. Accuracy and pre‐lineup confidence were not significantly correlated, although accuracy was related to post‐lineup willingness to testify. In the second experiment, undergraduate subjects were asked to read a summary of a trial, describing a situation similar to that studied in experiment 1; the independent variables were the presence of an earwitness, the gender and confidence of the earwitness, and the retention interval. Only the presence of an earwitness had a significant main effect upon mock jurors' verdicts. However, there was a significant interaction between witness confidence and witness gender when an earwitness identification was presented.