Ivana Rehman, PhD

Applied Linguistics & Technology, Iowa State University

Research Interests

L2 Pronunciation Learning & Teaching

L2 Pronunciation & Technology

Computer-Assisted Pronunciation Training

Oral Language Assessment & Rater Behavior

Research Products

Golden Speaker Builder (GSB) is an online interactive tool that allows L2 learners to build a personalized pronunciation model that mirrors their own voice but with a native accent (i.e. a “golden speaker”). Learners are able to create their own account, and build and save their golden speaker model. The provided voice produces intelligible speech with the voice quality of the L2 learner, and the prosody of the source native speaker normalized to the pitch range of the L2 learner. Learners can use the model voice and follow the exercises provided in order to practice their pronunciation. Our research so far shows that practising with GSB leads to improved fluency and comprehensibility.

This non-native English speech database includes recordings from twenty-four (24) non-native speakers of English whose L1s are Hindi, Korean, Mandarin, Spanish, Arabic and Vietnamese, and each L1 contains recordings from two male and two female speakers. Each speaker recorded approximately one hour of read speech from which we generated orthographic and forced-aligned phonetic transcriptions. We also manually annotated 150 utterances per speaker to identify three types of mispronunciation errors: substitutions, deletions, and additions, making it a valuable resource not only for research in voice conversion and accent conversion but also in computer-assisted pronunciation training.

Vowel Viewer

Vowel Viewer is tailored towards effective vowel production training based on results of current research and is grounded in second language acquisition theories – it is the first of this kind to be developed for vowel production training. It is expected that the results of this project will show that training with Vowel Viewer is not only effective, but efficient as it results in improvement of L2 vowel production after only five hours of interaction with the program. Such accessible and practical tool would be a useful addition to any L2 classroom, offering learners more motivation and enhancing learner achievement through engagement in individualized vowel production training.