Assessing the influence of phonetic variation on the perception of spoken threats

In spite of the belief that there is such a thing as a ‘threatening tone of voice’ (Watt, Kelly and Llamas, 2013), there is currently little research which explores how listeners infer traits such as threat from speakers’ voices. This thesis addresses the question of how listeners infer traits such as how threatening speakers sound, and whether phonetic aspects of speakers’ voices can play a role in shaping these evaluations. Additionally, it is sometimes the case that a victim of a crime will never see the perpetrator’s face but will hear the perpetrator’s voice. In such cases, attempts can be made to get the witness or victim to describe the offender’s voice. However, one problem with this is whether phonetically untrained listeners have the ability to accurately describe different aspects of speakers’ voices. This issue is also addressed throughout this thesis. Over five experiments, this thesis investigates the influence of a range of linguistic and phonetic variables on listeners’ evaluations of how threatening speakers sounded when producing indirect threat utterances. It also examines how accurately phonetically-untrained listeners can describe different aspects of speakers’ voices alongside their evaluative judgements of traits such as threat and intent-to-harm. As well as showing that a range of linguistic and phonetic variables can influence listeners’ threat evaluations, results support the view that caution should be adopted in over-reliance on the idea that people will “know a threat when they hear one” (Gingiss, 1986:153). This research begins to address the phonetic basis for the perceptual existence of a ‘threatening tone of voice’, along with how listeners evaluate and describe voices in earwitness contexts. Suggestions are made at the end of the thesis for improvements in the elicitation and implementation of accurate, meaningful information about speakers’ voices from linguistically-untrained listeners in evaluative settings involving spoken threats

Assessing the abilities of phonetically untrained listeners to determine pitch and speaker accent in unfamiliar voices

It is sometimes the case that a victim of a crime will never see the perpetrator’s face, but will be exposed to his or her voice. This could occur in situations such as masked robberies, telephone fraud, or the receipt of bomb threats via phone or voicemail. In such cases, attempts can be made by the police or intelligence services to get the witness or victim to describe the voice of the offender. However, there is a high likelihood that a given earwitness will lack the linguistic expertise and technical vocabulary of the kind used by trained phoneticians when they describe voices. One question that arises from this problem is whether phonetically untrained listeners have the ability, using verbal means, to accurately capture different aspects of speakers’ voices. This paper presents an experiment in which a group of listeners were tasked with assessing how ‘high-pitched’ the voices of 12 speakers were, along with providing a description of each speaker’s accent. These assessments were then compared to measured Fundamental Frequency (F0) values and prior knowledge of the speakers’ accents in order to assess listener performance. The results suggest that while some listeners have the ability to make reliable judgements of relative vocal pitch, the overall correlations between measured (F0) and perceived pitch were weak. With regard to accent, the results suggest that the more unfamiliar a speaker’s accent is to the listener, perhaps owing to the geographical distance of the area where the accent is spoken from the listener’s place of origin, the harder it will be for the listener to accurately describe that accent. We argue that testing the abilities of earwitnesses to assess aspects of speakers’ voices before their descriptions are used further would be a useful safeguard against the use of potentially inaccurate or erroneous earwitness evidence in police investigations

'For the Record': applying linguistics to improve evidential consistency in police investigative interview records

The ‘For the Record’ project (FTR) is a collaboration between a team of linguistic researchers and police in the England & Wales jurisdiction (E&W). The aim of the project is to apply insights from linguistics to improve evidential consistency in police interview transcripts, which are routinely produced by transcribers employed by the police. The research described in this short report is intended as a pilot study, before extension nationally. For this part of the project, we analysed several types of data, including interview audio and transcripts provided by one force. This identified key areas where current transcription practice could be improved and enhanced, and a series of recommendations were made to that force. This pilot study indicates that there are three core components of quality transcription production in this context: Consistency, Accuracy, and Neutrality. We propose that the most effective way to address the issues identified is through developing new training and guidance for police interview transcribers

Perceptual instability in police interview records: Examining the effect of pauses and modality on people’s perceptions of an interviewee

This article examines whether the representation of linguistic features within transcripts and audio recordings of police interviews can influence people’s perceptions of the interviewee. We specifically examine the influence of the representation of pauses through an experimental methodology. Participants were presented with a police interview either in audio format or in one of a series of transcript formats and asked to make a series of judgements about the interviewee. We manipulated both the presence and representation of pauses within the audio and transcript stimuli to assess how this would influence perceptions. Results showed differences between perceptions of the interviewee in the audio and transcript conditions, and that different representations of pauses within transcripts created perceptual instability between participants. The findings illustrate that the presence and representation of linguistic features in transcripts can affect perceptual judgements. We argue this should be explicitly considered by those using transcripts within the legal system

The role of face and voice cues in predicting the outcome of student representative elections

First impressions formed after seeing someone’s face or hearing their voice can affect many social decisions, including voting in political elections. Despite the many studies investigating the independent contribution of face and voice cues to electoral success, their integration is still not well understood. Here, we examine a novel electoral context, student representative ballots, allowing us to test the generalisability of previous studies. We also examine the independent contributions of visual, auditory and audiovisual information to social judgements of the candidates, and their relationship to election outcomes. Results showed that perceived trustworthiness was the only trait significantly related to election success. These findings contrast with previous reports on the importance of perceived competence using audio or visual cues only in the context of national political elections. The present study highlights the role of real-world context and emphasises the importance of using ecologically valid stimulus presentation in understanding real-life social judgement

Voice as a design material : sociophonetic inspired design strategies in Human-Computer Interaction

While there is a renewed interest in voice user interfaces (VUI) in HCI, little attention has been paid to the design of VUI voice output beyond intelligibility and naturalness. We draw on the field of sociophonetics - the study of the social factors that influence the production and perception of speech - to highlight how current VUIs are based on a limited and homogenised set of voice outputs. We argue that current systems do not adequately consider the diversity of peoples’ speech, how that diversity represents sociocultural identities, and how voices have the potential to shape user perceptions and experiences. Ultimately, as other technological developments have influenced the ideologies of language, the voice outputs of VUIs will influence the ideologies of speech. Based on our argument, we pose three design strategies for VUI voice output design - individualisation, context awareness, and diversification - to motivate new ways of conceptualising and designing these technologies

Perception of threat and intent to harm from vocal and facial cues

What constitutes a “threatening tone of voice”? There is currently little research exploring how listeners infer threat, or the intention to cause harm, from speakers’ voices. Here, we investigated the influence of key linguistic variables on these evaluations (Study 1). Results showed a trend for voices perceived to be lower in pitch, particularly those of male speakers, to be evaluated as sounding more threatening and conveying greater intent to harm. We next investigated the evaluation of multimodal stimuli comprising voices and faces varying in perceived dominance (Study 2). Visual information about the speaker’s face had a significant effect on threat and intent ratings. In both experiments, we observed a relatively low level of agreement among individual listeners’ evaluations, emphasising idiosyncrasy in the ways in which threat and intent-to-harm are perceived. This research provides a basis for the perceptual experience of a “threatening tone of voice,” along with an exploration of vocal and facial cue integration in social evaluation. </jats:p

Understanding the role of transcription in evidential consistency of police interview records in England and Wales

Evidential records of investigative interviews serve an important institutional purpose within the legal system in England and Wales. Academic scholars have long recognized that little institutional attention is paid to the transformation process that occurs when written records of the spoken are produced, nor to the potential impact this has on later interpretation by users of the records during the investigation of crimes and later in court. We analyse 29 digitally recorded investigative interviews and their corresponding official written ‘Record of Taped/Videoed Interview’ (ROTI/ROVI) transcripts, taking an ethnomethodological, conversation analytic (CA) approach to examine the social actions that are transformed in this activity by comparing the audio record of police interview evidence to the written transcripts. The intended outcome of this work, within the wider project of which this forms, is to better understand this process within the legal system, and to incite improvements