John M. Levis is Professor of English and Applied Linguistics at Iowa State University, USA. He is a veteran ESL teacher, and his research is focused on second language acquisition, especially second language pronunciation.

Tracey M. Derwing is Professor Emeritus of TESL in the Department of Educational Psychology at the University of Alberta, Canada and Adjunct Professor at Simon Fraser University. She focuses her research on L2 pronunciation and investigates the elements of successful social integration of immigrants and refugees.

Sinem Sonsaat-Hegelheimer is Assistant Professor of English and Applied Linguistics at Iowa State University, USA. Her research is focused on pronunciation teaching, computer-assisted language learning, and teaching materials evaluation.