Less than careful speech: Exploring the roles of target duration and time varying intensity in spoken language processing

Abstract

Despite substantial phonetic variation in the production of natural speech, listeners are quite adept at processing varying speech signals. Further, the recognition of spontaneous speech is a multifaceted problem where listeners are drawing information from many sources in the recognition process. Previous research has begun to outline the influence of both syntactic and semantic contributions to spoken word recognition; however, it has been argued (Ernestus et al., 2002; van de Ven et al., 2012) that such cues reach a ceiling in their contributions, and that acoustic information also aids the listener when processing language. There has been limited discussion on what information encoded within a given speech signal lends itself to more effectively processing spontaneous speech. The present study contributes to such a discussion, using responses from 85 participants in modified Cloze tasks and speech in noise manipulations, where results serve as a starting place to describe the contributions of duration and intensity in natural speech (as well as their relative effects on spoken language processing). The introduction of particular acoustic information—over and above syntactic and semantic cues—has been observed within this study as a statistically significant contributor to more effective spoken language processing.