Non-native tones are considered challenging for adult second language speakers to perceive and produce. The current study examined the effect of a laboratory-based intensive training in improving American English speakers’ tone production. Participants’ task was to repeat Mandarin words after the model. There were two conditions in the experiment: in one condition, participants did not get any external feedback; whereas in the other condition, participants received detailed visual feedback, which was the pitch contour of their tone production alongside the native version. Eight participants completed training with no feedback and another eight participants were trained with visual feedback. Results revealed that participants in both groups did not improve their tone production after training, and participants trained with visual feedback did not show more improvement than those trained with no feedback. Given the lack of improvement in participants’ tone production after training, methodological and theoretical limitations with respect to the use of a repetition-based training paradigm are discussed.

Recent studies have come to contradicting conclusions as to whether international adoptees, who experience a sudden change in language environment, lose or retain traces of their birth language (Pallier et al., 2003; Ventureyra, Pallier & Yoo, 2004; Pierce, Klein, Chen, Delcenserie, & Genesee, 2014). Though these studies have considered cortical differences between international adoptees and individuals from their birth counties, none has looked at subcortical differences in the brain between the two groups. The current project examined the frequency following response of adult Chinese international adoptees (N = 9) adopted as infants by American English-speaking families in the United States compared to native Mandarin (N = 21) and American English (N = 21) controls. Additional behavioral tasks were completed to explore different levels of linguistic features from phonetics to phonology to semantic knowledge to suprasegmental characteristics of speech. The FFR results indicate mostly good pitch tracking abilities amongst the adoptees that may support future tonal language learning in the adoptees. The behavioral data suggest that the adoptees have minimal access to all levels of linguistic levels of linguistic processing (i.e., phonetic, phonological, lexical, suprasegmental) after adoption and after early exposure to English. Overall, the data provide evidence for the neural commitment theory that humans’ language acquisition is attuned to their language environment early on in life.

L’objectif de cette étude est d’apporter une contribution aux recherches portant sur les effets prosodiques du contact de langues à travers l’étude du système prosodique du français centrafricain, une variété de français ayant émergé suite au contact avec une langue africaine à densité tonale maximale, le sango. La République centrafricaine est un pays extrêmement multilingue. Entre 60 et 100 langues y sont parlées, outre les deux langues officielles que constituent le sango – lingua franca, et le français – langue principale de l’enseignement et de l’administration publique. Dans la capitale, Bangui, le sango est la langue parlée d’ordinaire dans la vie quotidienne, tandis que le français s’utilise essentiellement dans des contextes professionnels. Cette étude se base sur des enregistrements de parole spontanée de 12 locuteurs francophones de Bangui. Des analyses acoustiques montrent que l’intonation du français centrafricain partage des caractéristiques communes avec le sango. La majorité de mots ont des patrons tonals qui restent inchangés quel que soit leur place dans l’énoncé, et chaque syllabe porte un ton. Le système se distingue ainsi considérablement du système intonatif du français européen où la courbe mélodique est contrainte au niveau post-lexical et dépend entre autres de facteurs rythmiques, syntaxiques et pragmatiques. La conclusion principale de cette étude est que le français centrafricain se classifie d’un point de vue typologique comme une langue à tons lexicaux. Il ressort que le système prosodique du français centrafricain est plus proche de celui du sango et que de celui du français européen. Les faits mis au jour dans cette thèse montrent que la prosodie peut changer de façon fondamentale dans une situation de contact de langue. / This study is concerned with prosody and language contact. The fact that language contact induces change is well documented, but few studies focus on the prosodic effects of contact-induced change. The aim of this study is to provide a case study of the prosodic system of the contact variety Central African French, which has emerged from the contact between French and the African tone language, Sango.The Central African Republic is a multilingual country with between 60 to 100 different regional languages spoken within its borders in addition to two official languages, the lingua franca Sango and French. French has been the main language of education and of public administration since colonial times. In the capital Bangui, Sango is the most used language in everyday communication whereas French is spoken in professional contexts. This study is based on recordings of spontaneous speech of 12 French-speaking informants from Bangui. Acoustic analyses of the recordings show that the prosody of Central African French shares with Sango some fundamental characteristics: most words have fixed tonal patterns independently of their position in the sentence and every syllable carries a static tone. This system greatly differs from the system of European varieties of French, where the sentence melody is determined at the post-lexical level and depends on factors such as rhythm, syntax and pragmatics. The main conclusion of this study is that Central African French may be classified as a tone language and thus is endowed with a prosodic system that is closer to Sango than to European French. This finding suggests that intonation might change radically in contact situations ; the change is not only superficial but concerns the underlying system.

Cette thèse vise à caractériser le traitement auditif des informations spectro-temporelles impliquées dans la perception de la parole au cours du développement précoce. Dans ce but, les capacités de discrimination de contrastes phonétiques sont évaluées à l’aide de deux méthodes comportementales chez des enfants âgés de 6 et 10 mois. Les sons de parole sont dégradés par des « vocodeurs » conçus pour réduire sélectivement les modulations spectrales et/ou temporelles des stimuli phonétiquement contrastés.Les trois premières études de cette thèse montrent que les informations spectro-temporelles fines de la parole (les indices de modulation de fréquence et détails spectraux) ne sont pas nécessaires aux enfants français de 6 mois pour percevoir le trait phonétique de voisement et de lieu d’articulation. Comme pour les adultes français, les informations de modulation d’amplitude les plus lentes semblent suffire pour percevoir ces traits phonétiques. Les deux dernières études montrent cependant que les informations spectro-temporelles fines sont requises pour la discrimination de tons lexicaux (variations de hauteur liée au sens de mots monosyllabiques) chez les enfants français et taiwanais de 6 mois. De plus, ces études montrent l’influence de l’expérience linguistique sur le poids perceptif de ces informations de modulations dans la discrimination de la parole chez les jeunes adultes et les enfants français et taiwanais de 10 mois.Ces études montrent que les mécanismes auditifs spectro-temporels sous-tendant la perception de la parole sont efficaces dès l’âge de 6 mois, mais que ceux-ci vont être influencés par l’exposition à l’environnement linguistique dans les mois suivants. Enfin, cette thèse discute les implications de ces résultats vis-à-vis de l’implantation précoce des enfants sourds profonds qui reçoivent des informations de modulations dégradées. / The goal of this doctoral research was to characterize the auditory processing of the spectro-temporal cues involved in speech perception during development. The ability to discriminate phonetic contrasts was evaluated in 6- and 10-month-old infants using two behavioral methods. The speech sounds were processed by “vocoders” designed to reduce selectively the spectro-temporal modulation content of the phonetically contrasting stimuli. The first three studies showed that fine spectro-temporal modulation cues (the frequency-modulation cues and spectral details) are not required for the discrimination of voicing and place of articulation in French-learning 6-month-old infants. As for French adults, 6-month-old infants can discriminate those phonetic features on the sole basis of the slowest amplitude-modulation cues. The last two studies revealed that the fine modulation cues are required for lexical-tone (pitch variations related to the meaning of one-syllable word) discrimination in French- and Mandarin-learning 6-month-old infants. Furthermore, the results showed the influence of linguistic experience on the perceptual weight of these modulation cues in both young adults and 10-month-old infants learning either French or Mandarin.This doctoral research showed that the spectro-temporal auditory mechanisms involved in speech perception are efficient at 6 months of age, but will be influenced by the linguistic environment during the following months. Finally, the present research discusses the implications of these findings for cochlear implantation in profoundly deaf infants who have only access to impoverished speech modulation cues.