Doctoral Dissertation Research: Developing phonetic training for improving the learning of second language stress

Stress, or the location of prominence within a word, may be encoded and used differently across languages. Second language (L2) learners whose native language does not use stress to contrast word meaning often face difficulty in perceiving stress in their L2. Even when both languages do use stress contrastively, stress acquisition may be challenging if the two languages differ in their phonetic cues used for stress, or if stress plays a stronger role in differentiating words in the L2 compared to the first. While phonetic training has been shown to be effective for improving the perception of L2 speech segments and tone acquisition, whether it is effective for improving suprasegmental stress perception in a L2 has not been well established. This doctoral dissertation investigates whether the perception of stress by L2 learners may be improved through phonetic training and whether the benefits of training generalize to untrained syllable positions. Additionally, this dissertation investigates the role of attention in the learning of L2 stress. The importance of attention for the acquisition of unfamiliar speech sounds has been discussed by L2 learning models, but few studies have examined its role during phonetic training for non-segmental features. Understanding whether phonetic training is effective for improving stress acquisition and the role that attention plays during training can help inform linguistic theories for L2 acquisition and aid in developing effective pedagogical methods for teaching second language stress. The doctoral dissertation aims to establish whether the perception and phonological processing of suprasegmental stress by L2 learners may be improved through phonetic training, the role that attentional allocation plays during the acquisition of suprasegmental features, and whether the benefits of training are generalizable to untrained syllable positions. The Automatic Selective Perception model posits that attentional focus is required during the early stages of L2 learning in order to successfully perceive and acquire novel L2 sounds. This predicts that mere exposure to L2 sounds may not result in improving perceptual accuracy if a learner’s attention is not directed towards the feature in question. The present dissertation provides participants with a series of four phonetic training sessions. While all participants are exposed to the same stimuli during training, they are split into two groups with different tasks: a stress group and a segmental group. The stress group receives feedback during training directing their attention to identifying stress placement, while the segmental group has their attention directed to initial consonant voicing. Four pre- and post-tests are given to measure performance differences after training: a sequence-recall task, two discrimination tasks (an AX task and a novel AQX task), and an identification task. In sum, this dissertation aims to contribute to our understanding of the role of attention during L2 stress acquisition and determine whether phonetic training is effective for improving stress perception for first and second language pairs that differ in their instantiation of stress. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.