This chapter explores the intricate relationship between music and language, highlighting their shared neural processing in the brain. It looks at the musicality of speech, demonstrating how acoustic features such as pitch, rhythm, and timbre convey meaning and emotion in both music and language. Research reveals that even those who consider themselves unmusical possess an innate musicality, evident in their ability to perceive subtle differences in speech sounds. The chapter emphasizes that language acquisition in infants relies heavily on musical aspects, such as melody, rhythm, and prosody. Brain imaging studies confirm an overlap in neural networks for music and language processing, including Broca’s and Wernicke’s areas, traditionally associated with language. This ’music-language network’ is active from infancy, suggesting a deep biological connection between these two forms of communication. The chapter also highlights the therapeutic potential of music for language development. Musical activities can enhance speech perception, rhythmic skills, and reading abilities, particularly in children with language disorders or dyslexia. By engaging with music, children can playfully develop essential mental faculties, fostering overall cognitive and emotional growth.

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.

The Automatic Selective Perception (ASP) model posits that listeners make use of selective perceptual routines (SPRs) that are fast and efficient for recovering lexical meaning. These SPRs serve as filters to accentuate relevant cues and minimize irrelevant information. Years of experience with the first language (L1) lead to fairly automatic L1 SPRs; consequently, few attentional resources are needed in processing L1 speech. In contrast, L2 SPRs are less automatic. Under difficult task or stimulus conditions, listeners fall back on more automatic processes, specifically L1 SPRs. And L2 speech perception suffers where there is a mismatch between the L1 and the L2 phonetics because L1 SPRs may not extract the important cues needed for identifying L2 phonemes. This chapter will present behavioral and neurophysiology evidence that supports the ASP model, but which also indicates the need for some modification. We offer suggestions for future directions in extending this model.

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.

This chapter outlines studies within the domain of speech perception by bilingual adult listeners. I first discuss studies that have examined bilinguals’ perception of L1 and/or L2 speech segments, as well as those that have tested perception of unfamiliar, non-native speech segments. In turn, I examine each of the factors that are known to affect bilinguals’ perception of speech, which include age of L2 acquisition, effects of L1:L2 usage as they pertain to language dominance and proficiency, and short-term contextual effects on speech perception. I also provide an overview of the literature on bilinguals’ perception of suprasegmentals. Finally, I explore what I think are some of the crucial questions facing the field of bilingual speech perception.

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?).

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.