Beating stress: Evidence for recalibration of word stress perception

Speech is inherently variable, requiring listeners to apply adaptation mechanisms to deal with the variability. A proposed perceptual adaptation mechanism is recalibration, whereby listeners learn to adjust cognitive representations of speech sounds based on disambiguating contextual information. Most studies on the role of recalibration in speech perception have focused on variability in particular speech segments (e.g., consonants/vowels), and speech has mostly been studied with a focus on talking heads. However, speech is often accompanied by visual bodily signals like hand gestures, and is thus multimodal. Moreover, variability in speech extends beyond segmental aspects alone and also affects prosodic aspects, like lexical stress. We currently do not understand well how listeners adjust their representations of lexical stress patterns to different speakers. In four experiments, we investigated recalibration of lexical stress perception, driven by lexico-orthographical information (Experiment 1) and by manual beat gestures (Experiments 2-4). Across experiments, we observed that these two types of disambiguating information (presented in an audiovisual exposure phase) led listeners to adjust their representations of lexical stress, with lasting consequences for subsequent spoken word recognition (in an audio-only test phase). However, evidence for generalization of this recalibration to new words was only found in the third experiment, suggesting that generalization may be limited. These results highlight that recalibration is a plausible mechanism for suprasegmental speech adaption in everyday communication and show that even the timing of simple hand gestures can have a lasting effect on auditory speech perception.