Spectral properties of anterior sibilant fricatives in Northern Peninsular Spanish and sibilant-merging and non-merging varieties of Basque

This paper focuses on the spectral properties of anterior sibilant fricatives in Northern Peninsular Spanish, and sibilant-merging and non-merging varieties of Basque. Non-merging varieties of Basque have two voiceless anterior sibilant fricatives, characterized as apico-alveolar and lamino-alveolar. In other Basque varieties, however, these two phonemes have merged with varying results. Twenty-four participants divided into four different groups have been studied. One group is a set of monolingual Spanish speakers from north-central Spain, while the remaining three are Basque–Spanish bilingual groups with different sibilant fricative systems in Basque. The goal is to describe the spectral properties of anterior sibilant fricatives and examine the effect of the L1-Basque sibilant system upon L2-Spanish. The Basque varieties chosen are: (i) Azpeitia Basque, where merging in favor of the lamino-alveolar sibilant fricative has occurred; (ii) Lemoa Basque, where the merging in favor of the apico-alveolar sibilant fricative is widespread; and (iii) Goizueta Basque, where no merging has happened. Participants took part in an elicitation task where they produced sentences containing target words with an intervocalic anterior sibilant fricative in Basque and Spanish. Bayesian probability was used for inferential statistics. Speakers of the non-merging Basque variety show the narrowest acoustic dispersion of /s/ in Spanish, as opposed to broader diffusion in the other three groups. Regarding L1 transfer, while the Azpeitia group does not show transfer into Spanish, the Lemoa and Goizueta groups do. Results show that /s/ is more fronted for monolingual Spanish speakers from north-central Spain than the previous literature has reported.