Optimizing Second Language Learning: An Examination of Individual Differences in Speech Processing and their Role in Language Learning

Project Information

OptiSeLL

Grant agreement ID: 793919

DOI

10.3030/793919

Project closed

EC signature date 21 February 2018

Start date 1 September 2019

End date 21 December 2021

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 170 121,60

EU contribution

€ 170 121,60

Coordinated by

BCBL BASQUE CENTER ON COGNITION BRAIN AND LANGUAGE
Spain

Periodic Reporting for period 1 - OptiSeLL (Optimizing Second Language Learning: An Examination of Individual Differences in Speech Processing and their Role in Language Learning)

Reporting period: 2019-09-01 to 2021-08-31

Summary of the context and overall objectives of the project

When hearing spoken language, listeners segment the speech stream into speech sounds and assign each sound to a phoneme category. Recent research has shown that individuals differ in how they perform this task; some listeners can make categorical decisions while maintaining fine-grained acoustic information, while others seem to take a more step-like approach, according to which, they ignore acoustic information within phoneme categories. In other words, taking the speech sound /b/ as an example, some listeners are better than others in telling apart a good instance of a /b/ sound compared to a not-as-clear /b/. According to traditional views, listeners’ speech perception is tuned to the phoneme categories of their native language such that between-category differences are amplified, while –in contrast– listeners learn to ignore within-category differences. In this context, perceptual sensitivity to within-category differences has been considered a marker of suboptimal speech processing; however, recent work suggests that perceptual sensitivity may actually be a helpful aspect of speech processing. This fellowship examined perceptual sensitivity to within-category differences in the context of multilingual environments.

This project pursued three main objectives: (1) To examine how individual differences in speech processing affect learning of novel phonological contrasts, and –ultimately– individuals’ ability to reach a high level of proficiency in a foreign language, (2) To examine whether individual differences in speech processing ultimately affect listeners’ ability to learn foreign words, and (3) To assess the degree to which exposure to different phonologies affects the flexibility of the speech processing. For this purpose, a combination of cutting-edge experimental behavioral and neurophysiological tasks were used.

This research has several implications. First, it enriches our understanding about the fundamental mechanisms of speech perception. Recent work has revealed that –contrary to traditional views– maintaining within-category acoustic information may be an important aspect of spoken language comprehension. The results of this research project further enrich and expand on this literature by examining these processes in a multilingual population. Second, the results of this project demonstrate that high sensitivity to within-category information predicts higher achieved proficiency in a foreign language. Moreover, this relationship held over and above the effects of other predictors such as the amount of time dedicated to learning the new language. Third, it was found that bilingual status also plays an important role in terms of predicting foreign language proficiency; specifically, we found that early bilingualism and high sensitivity to within-category acoustic information each predict foreign language proficiency in the absence of the other. Thus, this research has made significant contributions in helping us identify the factors that facilitate foreign language learning.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

This fellowship consisted of three experimental studies. Study 1 included 164 adult Spanish-Basque bilinguals with various levels of English proficiency. Participants performed a number of behavioral tasks aimed at assessing: (1) listeners’ sensitivity to acoustic differences within a phoneme category in their L1 (Spanish), (2) listeners’ proficiency in a foreign language (English), and (3) key control measures such as overall exposure to English and baseline hearing acuity. In addition, all participants reported detailed information about their history of exposure to different languages. Study 2 includes 60 native Spanish speakers with various levels of sensitivity to within-category acoustic differences. It consists of participants learning a non-native phonemic contrast, which they then have to use in order to learn a set of novel words in a foreign language. Learning at the phonemic and lexical level is assessed via electrophysiological and eye-tracking methods. Finally, Study 3 includes further statistical analyses of Study 1 data with the goal to assess whether higher exposure to diverse phonologies during adulthood leads more flexible speech perception.

First, results revealed that individual differences in speech processing can predict how likely it is for an individual to master a foreign language; higher sensitivity to within-category differences in L1 (Spanish) predicted higher English proficiency. Second, bilingual status was also found to play a role in determining an individual’s success in learning a new language; for individuals with low perceptual sensitivity, being exposed to more than one language in a young age (< 4yo) predicted higher success rate in learning a foreign language. Third, it was found that exposure to phonological diversity during adulthood does not predict later success in foreign language learning. Together these results provide valuable insights into the nature of individual differences in speech perception and their role in language learning.

In a nutshell, the results of this project suggest that: (1) individual differences in speech perception are likely due to differences in the encoding of acoustic cues, and (2) these differences, as well as individuals’ bi-/multi-lingual exposure early in life, have significant implications for individuals’ ability to master a foreign language.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

These findings have a clear impact on the fields of speech perception, second language learning, and bilingualism. They contribute to the long-standing debate about the nature of individual differences in phonological processing by demonstrating that the perceptual sensitivity to within-category differences is a fundamental aspect of speech perception largely stemming from the idiosyncratic use of acoustic cues. As such, this sensitivity seems to play an important role not only in the processing of one’s native language, but also in the process of acquiring a foreign language. Moreover, the observed effect of bilingual status suggests that speech perception is fundamentally shaped during the earliest years of a person’s life, such that early bilingual exposure seems to facilitate learning of a new language later in life. Thus, more broadly, these results show how individual differences in speech perception can play a role a listener’s ability to master a foreign language, over and above other factors such as the amount of time dedicated to learning that new language. Understanding how individual differences in speech perception affect language learning can have widespread societal implications, as it can inform teaching practices and guide policymaking that aims at maximizing educational outcomes in second language acquisition settings.

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