Contextual influences on speech perception in developmental populations

Abstract

A major goal of speech perception research has been to describe how listeners recognize individual consonants and vowels from the speech stream given rampant acoustic-phonetic variability in their instantiation. Findings in healthy adults indicate that listeners achieve perceptual stability, at least in part, by dynamically adjusting phonetic boundaries to accommodate contextual influences in speech production. The current work examines the developmental trajectory of such functional plasticity in typically developing children. Across two experiments, we examined the influence of speaking rate and place of articulation on stop consonant identification. Stimuli consisted of three voice-onset-time continua: “goal” to “coal” at a fast speaking rate, “goal” to “coal” at a slow speaking rate, and “bowl” to “pole” at a slow speaking rate. The results showed that 8-10-year-old children are sensitive to how these contextual influences pattern in speech production. Specifically, the identification responses indicated that the voicing boundary was located at longer VOTs for the slow compared to the fast speaking rate continuum and for the velar compared to the labial continuum. These findings suggest that perceptual sensitivity to contextual influences in speech production emerges early in development, illustrating a critical role for functional plasticity toward the healthy end-state system.