Studies of Initial Tonal Acquisition by American English Speakers Learning Yoruba

This thesis examines the perception and production of Yorùbá tone by adult American English speakers with no prior exposure to a tone language, investigating whether tonal acquisition is possible after the critical period. Using an elicited imitation experiment with forty-four participants divided into four groups — students in an elementary Yorùbá class, speakers of non-tonal L2s, speakers of Mandarin Chinese as an L2, and monolingual English speakers — the study finds that prior exposure to any tone language significantly improves tonal acquisition performance, and that near-native tonal proficiency remains achievable by adult learners. The thesis also identifies and describes an "upstep" phenomenon in Yorùbá tone not previously documented in the published literature. Pitch range data collected using Praat software is analyzed alongside error patterns across all participant groups. Originally submitted in August 2012 to the Department of English, Southern Illinois University Edwardsville, in partial fulfillment of the requirements for the Master of Arts degree, under the name Kolawole Olatubosun. Supervisor: Ronald P. Schaefer.