Abstract

The purpose of the current study was to gain a better understanding of speech adaptation by examining kinematic and acoustic adaptation to bite block perturbation over time. Fifteen native American English speakers (7 female, 8 male) with no history of speech, language, or hearing deficits participated in the study. Custom bite blocks were created for speakers which created a 10mm interincisal gap when inserted. Speakers produced five repetitions of the sentence, I say ahraw /ərɑ/ (as part of a larger set) prior to bite block insertion, immediately following bite block insertion, 2-mintues post insertion, 4-minutes post insertion, 6-minutes post insertion, and immediately following bite block removal. Participants’ speech was audio-recorded, and their lingual articulatory movements were measured with a Northern Digital Instruments Wave electromagnetic articulograph. The VC syllable /ɑɪs/ was analyzed kinematically from the midpoint of the /ɑɪ/ diphthong through production of /s/ using a custom Matlab application. Kinematic data were obtained via sensor coils placed in the tongue back, tongue mid, tongue front, jaw, lower lip and upper lip. Measures of displacement (mm), maximum velocity (mm/sec), and jaw contribution to the tongue and lower lip (mm) were taken during each recording. Spectral mean (Hz), standard deviation, skewness, and kurtosis were calculated for the central 50% of each /s/ production using acoustic analysis software. Kinematic analysis revealed no significant change in tongue measures upon bite block insertion or during the 6-minute adaptation period. In contrast, significant acoustic changes were observed upon bite block insertion and during the following 6 minutes, demonstrating adaptation over time. The changes observed in acoustic measures may have been a result of tongue shape changes and subsequent adaptations that were not detected via kinematic analysis. Future studies may provide further insight into the tongue’s ability to compensate for bite block perturbation by examining the relationship between mandibular positioning and tongue shape.

Degree

College and Department

David O. McKay School of Education; Communication Disorders

Rights

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