Date of Graduation

Spring 2014

Degree

Doctor of Audiology

Department

Communication Sciences and Disorders

Committee Chair

Letitia White

Keywords

mismatch negativity, mmn, electrophysiology, speech, hearing, audiology, place of articulation, voiced consonants, voiceless consonants

Subject Categories

Communication Sciences and Disorders

Abstract

The effects of different stimulus parameters, such as frequency, intensity, duration and the interstimulus interval (ISI) on the features of the mismatch negativity (MMN) have been studied extensively. Based on the Phillips, et al. (2000) design, this study examined the effects of multiple features of speech stimuli on the MMN response, predicting a larger amplitude response to multiple features. Three conditions were created: 1. A condition replicating the Phillips, et. al. (2000) design using a voicing continuum from /tӕ/ to /dӕ/. 2. A comparison condition using a continuum from a voiced bilabial consonant, /bӕ/, to a voiced alveolar consonant, /dӕ/. 3. Finally, a condition building upon the Phillips, et. al. (2000) design utilizing continua from voiced to voiceless consonants but at three different places of articulation, /tӕ/ to /dӕ/, /pӕ/ to /bӕ/, and /gӕ/ to /kӕ/. Results indicated multiple features tend to lower the amplitude of the MMN, a contrast to the original hypothesis. The difference in results may be attributable to the regularity-violation hypothesis of the MMN which posits that in order to elicit a robust MMN, participants must be able to accurately predict the next sound to occur in the sequence. The study does continue to further our understanding of how the auditory centers of the brain process categorical information.

Copyright

© Jaime Michelle Sutton

Campus Only

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