Biomechanically Conditioned Variation at the Origin of Diachronic Intervocalic Voicing

This paper addresses the question of how synchronic variation in intervocalic voicing of voiceless obstruents, as observed in several languages (e.g., Rome Italian /lato/ [lato] - [lado]), may initiate and give rise to a regular sound change (e.g., /t/ > /d/ between vowels). We hypothesize that a biomechanically motivated linkage between male gender, speech rate, and voicing may provide a way to accelerate the spread of the phenomenon and lead to an eventual generalized recategorization. In order to explore this hypothesis, first we reanalyze the results of a previous study on intervocalic voicing in Spanish, focusing on individual differences and, in particular, the possible role of gender. Then we report on a study of the same phenomenon in Basque, focusing also on interspeaker variation. Finally, we report on a controlled experiment where speech rate was manipulated.