Attentional Modulation and Individual Differences in Explaining the Changing Role of Fundamental Frequency in Korean Laryngeal Stop Perception.

Abstract

Previous research has shown differential degrees of attention in processing hierarchical linguistic information where higher order cues require greater attention in speech processing. The current study investigated the influence of attentional resources on acoustic cue weightings in speech perception by examining Korean listeners' identifications of the three-way laryngeal stops (tense vs. lax vs. aspirated). Using a dual-task paradigm, we presented 28 adult Korean listeners with identification tasks blocked by no-distractor versus distractor conditions where arithmetic calculations distracted the listeners' speech processing. Auditory stimuli were prepared by combining voice-onset times (VOTs) and fundamental frequencies (F0s) based on natural production. Group analyses revealed that VOT was an informative parameter across the three stop laryngeal categories and the listeners' reliance on VOT was consistently reduced under the distracting condition. Subsequent individual-level analysis further showed that listeners with heavier perceptual reliance on VOT were hindered by the distractor more than others in utilizing VOT. Unlike VOT, the F0 cue did not systematically interact with the distracting listening condition. The findings indicated that VOT (but not F0) required greater attention in processing the Korean laryngeal stops, and was presumably a higher order acoustic cue than F0. The current study contributes to the understanding of attention and cue primacy in general as well as to the clarification of the relative roles of VOT and F0 for the Korean stop laryngeal contrast.