This thesis comprises two papers. Paper One: Previous research in relation to young people who are at risk of school exclusion can be criticised for the lack of studies that truly elicit and foreground the voices of these young people within a school context. While retrospective studies have explored their views post exclusion, few have examined their perceptions within a mainstream context prior to exclusion. This can be explained in terms of the inherent difficulties of engaging disaffected young people with research, often attributed to a combination of poor language skills and negative perceptions of adults, and schools’ reluctance to foreground these voices. This paper reports how a participatory research method, which took into account the individual needs of disaffected young people, overcame these difficulties and succeeded in eliciting the voices of ten young people at risk of school exclusion within their mainstream context. Rich, meaningful and contextualised data were generated about disaffected young people’s perceptions of their mainstream school experiences. The data were thematically analysed and then interpreted using self determination theory (Ryan & Deci, 2000). This revealed that from young people’s perspectives the need for a sense of relatedness was more relevant than the need for a sense of autonomy. The need to feel competent only became relevant in certain subject contexts. Findings showed a more holistic and nuanced perspective of disaffection. The young people perceived their engagement to be context driven and, importantly, were able to view themselves as positively engaged with some aspects of school. This highlights the need for further research into disaffected young people’s voices regarding what they perceive to be positive engagement as this may differ from practitioners’ perceptions. Implications for practice are that Educational Psychologists (EPs) are well placed to foreground the voice of disaffected young people with practitioners. In so doing they help them make better sense of disaffected young people’s school experiences and enhance practitioners’ ability to support these young people. Paper Two: Interventions in relation to young people at risk of exclusion tend to be drawn from education practitioner views which focus on a particular perspective of disaffection such as within child or curricular factors. Consequently interventions are ‘done to’ rather than ‘with’ young people and lack an integrated, holistic approach. In this small case study the researcher facilitated an intervention with seven Learning Mentors (LMs) set within two different school contexts. The aim of the intervention was to engage LMs with the voice of disaffected young people. The LMs met in two groups over two months during which vignettes of disaffected young people’s voices were used as stimuli for prioritising, implementing and evaluating changes to current LM practice. LMs’ personal constructs of disaffected young people were elicited pre and post intervention. The findings reveal that when LMs are facilitated to engage with the voice of disaffected young people it can have a positive impact on their perceptions of those young people. The effectiveness of the impact was dependent on the context of the school, level of training received and the extent to which LMs engaged with the facilitative process. As this is one of few studies which have implemented an intervention to engage schools with the voice of disaffected young people, further research exploring whether the intervention could be replicated in other school contexts would be of value. This study adds to the body of knowledge on school disaffection in young people and indicates that EPs are well placed to manage facilitative processes aimed at engaging schools with the voices of disaffected young people. In doing so they support practitioners to broaden their understanding of these young people and, importantly, enable them to act on their voices.

La capacité humaine de reconnaitre et d’identifier de nombreux individus uniquement grâce à leur voix est unique et peut s’avérer cruciale pour certaines enquêtes. La méconnaissance de cette capacité jette cependant de l’ombre sur les applications dites « légales » de la phonétique. Le travail de thèse présenté ici a comme objectif principal de mieux définir les différents processus liés au traitement des voix dans le cerveau et les paramètres affectant ce traitement. Dans une première expérience, les potentiels évoqués (PÉs) ont été utilisés pour démontrer que les voix intimement familières sont traitées différemment des voix inconnues, même si ces dernières sont fréquemment répétées. Cette expérience a également permis de mieux définir les notions de reconnaissance et d’identification de la voix et les processus qui leur sont associés (respectivement les composantes P2 et LPC). Aussi, une distinction importante entre la reconnaissance de voix intimement familières (P2) et inconnues, mais répétées (N250) a été observée. En plus d’apporter des clarifications terminologiques plus-que-nécessaires, cette première étude est la première à distinguer clairement la reconnaissance et l’identification de locuteurs en termes de PÉs. Cette contribution est majeure, tout particulièrement en ce qui a trait aux applications légales qu’elle recèle. Une seconde expérience s’est concentrée sur l’effet des modalités d’apprentissage sur l’identification de voix apprises. Plus spécifiquement, les PÉs ont été analysés suite à la présentation de voix apprises à l’aide des modalités auditive, audiovisuelle et audiovisuelle interactive. Si les mêmes composantes (P2 et LPC) ont été observées pour les trois conditions d’apprentissage, l’étendue de ces réponses variait. L’analyse des composantes impliquées a révélé un « effet d’ombrage du visage » (face overshadowing effect, FOE) tel qu’illustré par une réponse atténuée suite à la présentation de voix apprise à l’aide d’information audiovisuelle par rapport celles apprises avec dans la condition audio seulement. La simulation d’interaction à l’apprentissage à quant à elle provoqué une réponse plus importante sur la LPC en comparaison avec la condition audiovisuelle passive. De manière générale, les données rapportées dans les expériences 1 et 2 sont congruentes et indiquent que la P2 et la LPC sont des marqueurs fiables des processus de reconnaissance et d’identification de locuteurs. Les implications fondamentales et en phonétique légale seront discutées. / The human ability to recognize and identify speakers by their voices is unique and can be critical in criminal investigations. However, the lack of knowledge on the working of this capacity overshadows its application in the field of “forensic phonetics”. The main objective of this thesis is to characterize the processing of voices in the human brain and the parameters that influence it. In a first experiment, event related potentials (ERPs) were used to establish that intimately familiar voices are processed differently from unknown voices, even when the latter are repeated. This experiment also served to establish a clear distinction between neural components of speaker recognition and identification supported by corresponding ERP components (respectively the P2 and the LPC). An essential contrast between the processes underlying the recognition of intimately familiar voices (P2) and that of unknown but previously heard voices (N250) was also observed. In addition to clarifying the terminology of voice processing, the first study in this thesis is the first to unambiguously distinguish between speaker recognition and identification in terms of ERPs. This contribution is major, especially when it comes to applications of voice processing in forensic phonetics. A second experiment focused more specifically on the effects of learning modalities on later speaker identification. ERPs to trained voices were analysed along with behavioral responses of speaker identification following a learning phase where participants were trained on voices in three modalities : audio only, audiovisual and audiovisual interactive. Although the ERP responses for the trained voices showed effects on the same components (P2 and LPC) across the three training conditions, the range of these responses varied. The analysis of these components first revealed a face overshadowing effect (FOE) resulting in an impaired encoding of voice information. This well documented effect resulted in a smaller LPC for the audiovisual condition compared to the audio only condition. However, effects of the audiovisual interactive condition appeared to minimize this FOE when compared to the passive audiovisual condition. Overall, the data presented in both experiments is generally congruent and indicate that the P2 and the LPC are reliable electrophysiological markers of speaker recognition and identification. The implications of these findings for current voice processing models and for the field of forensic phonetics are discussed.