Martin J. Ball is Hawthorne-BORSF Endowed Professor, and Head of the Department of Communicative Disorders, and Director of the Doris B. Hawthorne Center for Special Education and Communication Disorders at the University of Louisiana at Lafayette. He is an Honorary Fellow of the Royal College of Speech and Language Therapists (London). Dr Ball has authored and edited twenty books, over 20 contributions to collections and over thirty refereed articles in academic journals. He is co-editor of the journal Clinical Linguistics and Phonetics. His main research interests include clinical phonetics and phonology, and the linguistics of Welsh. He is currently President of the International Clinical Phonetics and Linguistics Association.

Nicole Müller is Associate Professor in Communicative Disorders at the University of Louisiana at Lafayette, and also holds a Hawthorne- BORSF professorship. Dr Müller has published widely in both book and journal form in various areas of language disorders, as well the syntax and semantics of natural language. Particular areas of interest include historical and comparative Celtic linguistics, clinical discourse studies and pragmatics, specifically as applied to Alzheimer's Disease, communication disorders and multilingualism, and professional voice use in university professors.