Through a case study of the ‘speaking machine’ constructed by doctor-poet Erasmus Darwin between 1770 and 1771, this chapter aims to demonstrate that Romantic-era projects on the mechanics of speech were both new and controversial in their potential to undermine the religious, political, and philosophical status quo. It explores how Darwin’s simultaneous investigations of anatomy and machinery are suggestive of a materialist approach to the human, and particularly the speaking, body and how his materialist model of speech production simultaneously allows and is allowed by Darwin’s dual identity as philosopher and physician which informs the interdisciplinarity of his thought and practice. The chapter concludes by making the case that Darwin’s multidisciplinary approach to speech underpins both politicised reactions to his work and his own account of the role that a materialist understanding of speech and the voice can play in the development and improvement of society.

Study abroad is typically viewed as a catalyst for pronunciation learning because it affords learners both massive amounts of L2 input and abundant opportunities for meaningful L2 use. Yet, even in such an environment, there is substantial variability in learning trajectories and outcomes. The nature of the target structure is also a powerful determinant of learning; some structures seem to develop effortlessly, whereas others do not improve much at all. Additionally, study abroad research brings to light the important issue of speaker identity, as learners often make decisions about how they want to sound and what pronunciation features they will adopt. This chapter examines developmental time frames, trajectories, and turning points in the phonetics and phonology of L2 learners in a study abroad context. We also describe how learners acquire the regional pronunciation variants of their host communities considering the phonetics of the target feature and learners’ attitudes and beliefs. We argue that study abroad should be situated within a dynamic, longitudinal, and context-dependent view of phonetic and phonological learning.

Researchers in bilingualism seek to identify factors that are associated with specific features of bilingual speech. One such predictive factor is language dominance, typically understood as the degree to which one of the languages of a bilingual is more often and more proficiently used. In this chapter we review landmark studies that demonstrate the power of language dominance in predicting fine-grained phonetic and phonological characteristics of speech production and on the perceptual and processing abilities in one or both languages of bilinguals. We then critically examine the construct of dominance and identify ways that dominance can be and has been measured, as well as challenges inherent in the measurement of dominance. We follow demonstrating the dynamic character of dominance by reviewing research on dominance switches and shifts. This is followed by a review of extant studies on language dominance in bilingual speech production, perception, and processing in both languages. We conclude with four areas where research can be fruitfully directed.

This chapter reviews research on the phonetic and phonological production patterns of children exposed to two or more languages in early childhood. Much of the research has examined whether bilingual children differ from monolingual children in their production patterns and, when differences have been found, whether such patterns can be explained by language-internal (e.g., the influence of the phonological properties of one language on the other), language-external (e.g., language input or dominance), or other factors (e.g., the developing lexicon). We focus on language-internal influences, also referred to as cross-linguistic interaction, and review models that have been used to account for interaction. Our findings reveal that, while systematic differences between monolingual and bilingual speech exist, the differences are not large and may be explained by multiple factors. The chapter concludes with a discussion of research limitations which include small participant numbers and a predominance of certain language pairs, factors that have hindered attempts to model cross-linguistic interaction.

This chapter provides a thorough, up-to-date review of the literature on the phonetics and phonology of early bilinguals. It pulls together studies from a range of bilingual settings, including bilingual societies and heritage language contexts. While the chapter mostly reviews evidence from adolescent and adult participants, it also makes reference to the child bilingualism literature, where appropriate. The chapter first reviews studies on the accents of early versus late bilinguals, followed by a discussion of the various explanatory accounts for the observed differences between these two groups. Subsequently, the critical significance of early linguistic experience on bilingual speech patterns is considered, with particular reference to the evidence from childhood overhearers and international adoptees. The following sections then review studies comparing simultaneous and early sequential bilinguals, and those exploring the role of language dominance, continued use, the language of the environment in bilinguals’ pronunciation patterns, and the role of sociolinguistic factors in early bilingual speech patterns. The chapter concludes with suggestions for future research.

This chapter reviews evidence that the orthographic forms (spellings) of L2 sounds and words affect L2 phonological representation and processing. Orthographic effects are found in speech perception, speech production, phonological awareness, and the learning of words and sounds. Orthographic forms facilitate L2 speakers/listeners – for instance in lexical learning – but also have negative effects, resulting in sound additions, deletions, and substitutions. This happens because L2 speakers’ L2 orthographic knowledge differs from the actual working of the L2 writing system. Orthographic effects are established after little exposure to orthographic forms, are persistent, can be reinforced by factors other than orthography, including spoken input, and are modulated by individual-level and sound/word-level variables. Future research should address gaps in current knowledge, for instance investigating the effects of teaching interventions, and aim at producing a coherent framework.

Many have expressed concerns regarding the replicability of scientific research. However, little of this ongoing discussion has focused on research examining the production of vowels and consonants or the many important choices that researchers must make in pre-analysis phases of speech production research. The literature reviewed here indicates that not all speech production studies have been replicated, and that how speech is elicited may affect the results that are obtained. Many different elicitation techniques are in current use, but none represents a gold standard. The new Characteristic Speech Production (CSP) technique presented here aims to augment replicability by obviating the need for participants to accommodate their speech to that of others or adopt a particular speaking style as they give meaningful answers to meaningful questions. Given the novelty of the CSP technique, the chapter provides a protocol that is designed to test its efficacy. If the CSP technique can be shown to yield speech samples that are more representative of individuals’ speech than a standard list-reading technique, a change in how speech is elicited for production research will be warranted.

This chapter examines the acquisition of vowels and consonants in perception and production during typical second language (L2) acquisition by sequential, dominant bilinguals. The acoustic and articulatory studies reviewed serve to illustrate general patterns of L2 segmental learning with a focus on four principal themes, each structured around one or two main research questions: 1) cross-linguistic influence (How does a sequential, dominant bilingual’s first language shape L2 segmental perception and production?); 2) development (Are there universal patterns to L2 segmental speech development? Are certain vocalic and consonantal phenomena acquired more easily?); 3) inter- and intralearner variability (What are the sources of differences in perception and/or production between learners and for the same learner over time and in different communicative contexts?); and 4) training effects (What are the effects of training on learning? How do variables such as task and stimuli type condition effectiveness?).

Adults undertaking the endeavor of learning a new language can attest to the difficulty involved with producing the sounds and prosody of the target language. A principal aim of research on adult speech production is to comprehend the mechanisms and processes that differentiate adult bilingual speech development from bilingual speech that develops earlier in life. It is clear that individuals who learn an additional language in adulthood typically encounter some difficulties that early learners do not. In particular, these difficulties arise at the segmental level when acquiring novel sound categories and novel sound contrasts, as well as at the suprasegmental level when learning to produce non-native prosodic structures related to intonation, stress, rhythm, tone, and tempo. The present chapter provides a selective overview of the current state-of-the-art in adult bilingual speech production. Furthermore, this chapter considers theoretical and methodological areas for improvement, as well as avenues for future research.

Evidence that listeners attend to and track subphonemic phonetic details is indicated by listeners’ ability to reliably connect subphonemic variation and, often, socio-indexical associations in ways that align with the patterns realized in production. Bilinguals are presented with the task not only of associating within-language variation (e.g., social group X is connected to a particular range of phonetic realizations within language Y) but also of attending to how ethnolects and bilingually accented speech index social categories across languages. Having access to multiple languages also gives bilingual speakers a larger repertoire with which to index language- and community-specific social meaning. This chapter outlines the linguistic structures bilinguals may connect across their languages and then presents a specific exemplar model, noting the opportunities within the model’s structure for bilingual dynamics. The heterogeneity of bilingual individuals and speech communities is necessarily addressed, as this dynamic adds to the complexity and intrigue of studying bilingual populations.

In this chapter, we thoroughly describe the L2LP model, its five ingredients to explain speech development from first contact with a language or dialect (initial state) to proficiency comparable to a native speaker of the language or dialect (ultimate attainment), and its empirical, computational, and statistical method. We present recent studies comparing different types of bilinguals (simultaneous and sequential) and explaining their differential levels of ultimate attainment in different learning scenarios. We also show that although the model has the word “perception” in its name, it was designed to also explain phonological development in general, including lexical development, speech production, and orthographic effects. The chapter demonstrates that the L2LP model can be regarded as a comprehensive theoretical, computational, and probabilistic model or framework for explaining how we learn the phonetics and phonology of multiple languages (sequentially or simultaneously) with variable levels of language input throughout the life span.