Phonetic Category Formation is Perceptually Driven During the Early Stages of Adult L2 Development

Abstract

Research on the acquisition of L2 phonology in sequential language learners has stressed the importance of language use and input as a means to accurate production and perception; however, the two constructs are difficult to evaluate and control. This study focuses on the role of language use during the initial stages of development of phonetic categories related to stop voicing and analyzes the relationship between production and perception. Native English-speaking late learners of Spanish provided production/perception data on a weekly basis throughout the course of a seven-week immersion program in which L1 use was prohibited. The production/perception data were analyzed using generalized linear mixed effects models. Generalized additive mixed models were used to analyze and compare the learning trajectories of each modality. The analyses revealed phonetic learning in both production and perception over the course of the program. Perception gains paralleled those of native bilinguals by the conclusion of the program and preceded production gains. This study is novel in that it provides production/perception data in a semi-longitudinal design. Moreover, the beginning adult learners are examined in a learning context in which L1 use was minimal and L2 input was maximized. Taken together, the experiments suggest that L2 phonetic category formation can occur abruptly, at an early stage of development, is perceptually driven, and appears to be particularly fragile during the initial stages of learning.

Revisiting Perception–Production Relationships: Exploring a New Approach to Investigate Perception as a Time‐Varying Predictor

“…The fact that the between‐subjects but not within‐subjects perception predictors were significantly related to production in the current study intersects with previous research showing significant positive correlations when perception and production are sampled cross‐sectionally (e.g., Evans & Alshangiti, 2018; Flege et al., 1999; Saito & van Poeteren, 2017) but varying degrees of alignment when the two modalities are sampled longitudinally (Casillas, 2020a; Hanulíková et al., 2012; Kartushina et al., 2015; Nagle, 2018). Given the growing body of work on the topic, there seems to be an emerging consensus that “accurate L2 speech perception is not sufficient for accurate L2 speech production” (Kartushina et al., 2015, p. 828) or that the relationship between the two modalities is at least more complex and time‐sensitive (e.g., Nagle, 2018) than current theory would suggest.…”

“…Given that the speech learning model (Flege, 1995) hypothesizes that listeners must discriminate similar sounds before they can create a new phonetic category in the L2, an identification task, where listeners must associate an auditory stimulus with a category label, may be a more appropriate measure of perceptual learning (i.e., category formation) than the categorial discrimination task used in this study. Along the same lines, other approaches to operationalizing perception and production accuracy, such as through the use of crossover boundaries (Casillas, 2020a), may prove beneficial. Simply put, until a larger body of longitudinal studies has been accumulated, definitive conclusions about the time‐varying nature of the perception–production link cannot be reached.…”

“…In contrast to training studies, many of which have examined the link over two to three data points, at least two studies have assessed perception and production in multiwave designs. Casillas (2020a) assessed English speakers’ perception and production of Spanish stops on a weekly basis while learners were enrolled in a 6‐week summer immersion program. He found that both perception and production improved, but changes in perception boundaries occurred before changes in production boundaries.…”

Advancing the State of the Art in L2 Speech Perception-Production Research: Revisiting Theoretical Assumptions and Methodological Practices

“…For example, a weak correlation could signal a lagged relationship, in which case cross-lagged measures would show a stronger relationship than their time-locked counterparts. To that point, longitudinal developmental studies-studies that observed perception-production relationships over time without providing training in either modality-point to a lagged model (Casillas, 2020a(Casillas, , 2020bNagle, 2018).…”

“…Listeners heard each stimulus and were asked to classify it using a closed set of options. Similar tasks have been used to evaluate L2 listeners' reliance on spectral and duration cues in the perception of L2 vowel contrasts (e.g., Flege et al, 1997;Sakai, 2016) and to gain insight into the precise location of L2 phonemic boundaries, including how such boundaries change over time as a function of L2 experience (e.g., Casillas, 2020b).…”