Variable production and indexical social meaning: On the potential physiological origin of intervocalic /s/ voicing in Costa Rican Spanish

In several dialects of Spanish, men tend to exhibit more intervocalic /s/ voicing than women, e. g., oso ‘bear’ as [ozo], and this difference may have a physiological basis. File-Muriel et al. (2015, Disentangling the physiological from the socially-learned in gradient, sociophonetic processes: Evidence from s-realization in Barranquilla, Colombia. Unpublished manuscript) found that vocal tract size conditions /s/ aspiration in Barranquilla, and Nadeu and Hualde (2013, Reinterpretation of biomechanics as gender-conditioned variation in the origin of diachronic intervocalic voicing. Available at http://washo.uchicago.edu/pub/workshop/nadeu.pdf) contend that speakers with larger vocal tracts may have greater difficulty controlling vocal fold cessation. The present work serves as a continuation of these studies, utilizing 18 sociolinguistic interviews to determine (i) what factors are most predictive of intervocalic [z] in Costa Rica and (ii) whether physiology can potentially explain its origin. The results of a statistical analysis using 1,647 tokens of /s/ show that both gender and physiological factors significantly condition voicing (p < 0.001), with more voicing in men’s speech, as F2 decreases, and as f0 decreases. However, one would expect more gradient voicing in men’s speech if physiological factors caused the gender-based voicing difference, but women voice more gradiently while men produce higher rates of 0 % and 100 % voicing. We conclude that while physiological factors may have been its original source, non-physiological factors currently condition /s/-voicing in Costa Rica, with male speakers aiming for categorical targets for social motivations.