INDIVIDUAL DIFFERENCES IN VOWEL COMPACTNESS PERSIST UNDER INTOXICATION ACROSS FIRST AND SECOND LANGUAGES Charles B. Chang, Kevin Tang, & Andrew Nevins * Boston Univ.; Heinrich-Heine-Universität Düsseldorf & Univ. of Florida; Univ. College London cbchang@post.harvard.edu, Kevin.Tang@hhu.de, a.nevins@ucl.ac.uk ABSTRACT Alcohol intoxication facilitates inhibition of one’s first language (L1) ego, which may lead to reduced individual differences among second language (L2) speakers under intoxication. This study examined whether, compared to speaking while sober, speak- ing while intoxicated would reduce individual dif- ferences in the acoustic compactness of vowel cate- gories in sequential bilinguals exemplifying diverse L1–L2 pairs (German–English, Korean–English). Vowel compactness in F 1 × F 2 space varied by lan- guage (German, Korean, English) and by vowel, and was generally lower in intoxicated compared to sober speech, both across languages and throughout a bilingual’s language repertoire. Crucially, how- ever, there was still a wide range in compactness un- der intoxication; furthermore, individuals with more compact vowels while sober also produced more compact vowels while intoxicated, in both L1 and L2. Taken together, these findings show patterned variability of vowel compactness, suggesting that articulatory precision is an individual-difference di- mension that persists across speaking conditions and throughout the repertoire. Keywords: compactness, individual differences, vowels, bilingualism, alcohol. 1. INTRODUCTION How does drinking affect one’s speech? A grow- ing literature on alcohol intoxication and spoken lan- guage production suggests that there may not be a simple answer to this question. On the one hand, several studies have found, consistent with the gen- eral decline of motor control under intoxication, that intoxication degrades speech, in terms of more er- rors, less precise gestural coordination, more conso- nant lenition, slower speech rate, greater pitch vari- * We gratefully acknowledge the data contributions and re- search assistance of Kai Xin Bao, Marissa Carl, Erik Duch- nowski, Jenny Geng, Sam Green, Michael Hindley, Young Shin Kim, Peyton Krinsky, Ji Hye Kwon, Wen Jia Liu, Eliana Mugar, Yin Wang, Yifan Wu, and Steven Zhang, as well as the helpful feedback of two anonymous reviewers. ability, and/or lower intelligibility [1, 2, 3, 4, 5, 6, 7, 8]. On the other hand, studies that have exam- ined intoxication effects on speech in a bilingual’s second language (L2), in isolation or in comparison to speech in their first language (L1), have often ob- served that intoxication affects L2/nonnative speech differently from L1 speech [7, 9]. For example, in- toxication improved L1 German speakers’ pronunci- ation in Dutch [10], which can be explained in terms of intoxication making a speaker’s “language ego” less L1-biased, facilitating nonnative speech [9]. The possibility of facilitative intoxication raises interesting questions for L2 speech research. For one, if intoxication improves L2 production, might it “level the playing field” among L2 learners, who often show marked individual differences even from the same L1 background [11, 12, 13, 14, 15]? L2 speech research has been increasingly concerned with accounting for individual differences, linking them to factors such as cue-weighting preferences, memory variation, and perceptual and neural differ- ences [16, 17, 18, 19, 20]. In this study, we focused on individual differences in compactness, the acous- tic consistency of a phonetic category’s production [21], thought to reflect the “consistency of [speak- ers’] phonological-motor mapping” [22, p. 826]. Part of a larger project examining intoxication ef- fects on bilingual speech, the current study asked how individual differences among bilinguals in vowel compactness would be affected by intoxica- tion, across L1 and L2. Based on findings of intox- ication degrading L1 but facilitating L2 speech, we hypothesized that intoxication would result in less compact L1 vowels, yet—by enhancing access to L2 phonological-motor mappings—more compact L2 vowels. Given the persistence of variation in com- pactness across L1 and L2 [21, 22], intoxication- induced changes in compactness were not predicted to reduce individual differences in L1; that is, ha- bitually “less compact” speakers were predicted to become even less compact under intoxication along with “more compact” speakers. In contrast, if intox- ication does indeed have an L2-specific facilitation effect (and there is an upper limit on compactness), it could allow less-compact speakers to “catch up” 3. Speech Production and Speech Physiology ID: 1035 1182