The increasing importance of voice onset time in the perception and production of Zurich German plosives: An ongoing sound change

Recent evidence suggests an ongoing sound change in Zurich German, where the primary cue between lenis and fortis plosives is commonly considered to be closure duration, while both plosive types are traditionally unaspirated and phonetically voiceless. There has been a shift toward more lexical items being aspirated by younger speakers, who also are shown to produce generally longer voice onset times (VOTs) in comparison to older speakers. The current study investigates word-medial and word-initial plosives in speech perception and production. Using the apparent-time paradigm, two experiments were conducted with 48 speakers of Zurich German belonging to 2 age groups. Results confirm that younger speakers produce more aspiration in word-initial fortis plosives than older speakers but disconfirm previous findings which found a reduction in closure duration of fortis plosives. Results from the perception experiment reveal that, word-initially, VOT seems to increase in importance and closure duration is not always sufficient in distinguishing between lenis and fortis plosives. Results further highlight the importance of lexical differences, according to which production and perception are either aligned or misaligned. Overall, the current study provides evidence for a sound change affecting word-initial fortis plosives in Zurich German in speech perception and production.