Evidence For Selective Adaptation and Recalibration in the Perception of Lexical Stress

Hans Rutger Bosker

doi:10.1177/00238309211030307

Abstract

Individuals vary in how they produce speech. This variability affects both the segments (vowels and consonants) and the suprasegmental properties of their speech (prosody). Previous literature has demonstrated that listeners can adapt to variability in how different talkers pronounce the segments of speech. This study shows that listeners can also adapt to variability in how talkers produce lexical stress. Experiment 1 demonstrates a selective adaptation effect in lexical stress perception: repeatedly hearing Dutch trochaic words biased perception of a subsequent lexical stress continuum towards more iamb responses. Experiment 2 demonstrates a recalibration effect in lexical stress perception: when ambiguous suprasegmental cues to lexical stress were disambiguated by lexical orthographic context as signaling a trochaic word in an exposure phase, Dutch participants categorized a subsequent test continuum as more trochee-like. Moreover, the selective adaptation and recalibration effects generalized to novel words, not encountered during exposure. Together, the experiments demonstrate that listeners also flexibly adapt to variability in the suprasegmental properties of speech, thus expanding our understanding of the utility of listener adaptation in speech perception. Moreover, the combined outcomes speak for an architecture of spoken word recognition involving abstract prosodic representations at a prelexical level of analysis.

Highlights

The speech produced by the talkers we encounter in our everyday lives is highly variable: each talker has its own pronunciation habits
The present paper demonstrates that two types of such listener adaptation—selective adaptation and recalibration— extend to suprasegmental cues to lexical stress
The specific kind of retuning involved in selective adaptation is debated (Bowers et al, 2016; Kleinschmidt & Jaeger, 2015, 2016; Mitterer et al, 2018; Samuel, 2020), it is generally assumed to operate at multiple different levels, ranging from low-level auditory processing all the way up to decision-making (Remez, 1980; Samuel & Kat, 1996), supporting the representation of sensory information (Kleinschmidt & Jaeger, 2016)

Summary

Introduction

Acoustically very similar to another talker’s /ɛ/ (Ladefoged & Broadbent, 1957). One perceptual mechanism that helps listeners cope with this variability is adaptation: listeners may adjust perceptual boundaries between sound categories in response to previous exposure to a given talker’s speech. Dutch participants already preferentially fixated OCtopus well before hearing the segmentally disambiguating /p/ in the third syllable This finding, replicated in English (Jesse et al, 2017) and Italian (Sulpizio & McQueen, 2012), demonstrates that listeners use acoustic cues to lexical stress immediately and incrementally to support and constrain spoken word recognition. Experiment 1 targeted selective adaptation: Dutch participants passively listened to 24 exposure stimuli, after which they categorized six test stimuli sampled from a lexical stress continuum of the minimal word pair CAnon /ˈka:.nɔn/ “canon” versus kaNON /ka:.ˈnɔn/ “cannon.” Exposure stimuli involved either: (a) disyllabic words with a trochaic stress pattern (i.e., a strong–weak prosodic pattern; e.g., KAper /ˈka:.pər/ “hijacker”); (b) disyllabic words with an iambic stress pattern (i.e., weak– strong; e.g., kaPEL /ka:.ˈpɛl/ “chapel”); or (c) monosyllabic control words (e.g., kaas /ka:s/ “cheese”). It was predicted to find no difference between the two participants’ groups in the “non-word control” version of Experiment 2

Experiment 1

Method

Results

Interim summary

Experiment 2

General discussion