Second Language Acquisition of Regionally Indexed Phonological Variation: The Case of the Castilian Spanish /θ/

Abstract

This dissertation examines perception and production of the regionally indexed interdental fricative /θ/ found in north-central Spain among first language (L1) English second language (L2) Spanish speakers. Specifically, this study explores the relationship between L2 learners’ perceptual discrimination of /θ/ and /s/, grapheme-to-phoneme (re)mapping of /θ/ to follow Castilian Spanish norms, and language attitudes on variable acquisition of the /θ/. Additionally, this study conducts an acoustic analysis to analyze [θ] realizations among L2 learners who adopt /θ/ to investigate potential differences in phonetic realizations of this sound between L2 and native speakers.

Twenty study abroad (SA) L2, 27 advanced L2, and 29 native Castilian Spanish speakers participated in four tasks to explore learners’ perception, mapping, and production of /θ/ and /s/, and language attitudes: an ABX discrimination task, a four-alternative forced choice identification task (Schmidt, 2018), a verbal guise task, and a picture description task. Forty tokens of /θ/ and /s/ per speaker were acoustically analyzed (Beristain 2022; Regan, 2022). Mixed-effects models were run to determine how perception and individual factors like time abroad and attitudes impact production of /θ/ and /s/.

The findings show that the SA L2 learners were significantly less accurate at discriminating and mapping /θ/ and /s/ than the advanced L2 and native speakers who patterned similarly. Additionally, participants perceived Castilian Spanish as sounding friendlier than Non-Castilian Spanish. Advanced L2 speakers’ use and acoustic realizations of /θ/ showed development toward native-like patterning while the SA L2 learners’ production of /θ/ was infrequent. These findings contribute to variationist SLA and phonetics/phonology by showing that the acquisition of regional variants involves complex perceptual and productive processes influenced by multiple factors. This study also highlights the importance of acoustic analyses in capturing fine-grained differences in phonological development, demonstrating that advanced learners can approximate native-like patterns in both perception and production.