2011-Present Member, Chairs Advisory Committee, College of Arts and Sciences, The Ohio State University
2010-Present Member, Steering Committee, Center for Cognitive Science, The Ohio State University
2010-Present Member, Steering Committee, Center for Cognitive and Behavioral Brain Imaging, the Ohio State University
2008- Present Adjunct Professor, Center for Advanced Study of Language, University of Maryland.
2008- Present Chair, Steering Committee, Buckeye Language Network, The Ohio State University.
2002- Present Co-Coordinator, Disabilities Minor Program, The Ohio State University
2002- 2010 Co-Coordinator, American Sign Language Program, The Ohio State University
1998- Present Courtesy Appointment, Professor, Department of Linguistics, The Ohio State University.
1995- Present Chair, Department of Speech and Hearing Science, The Ohio State University.
1992- Present Professor, Department of Speech and Hearing Science, The Ohio State University.
1986-92 Associate Professor, Department of Speech and Hearing Science, The Ohio State University.
1983-86 Assistant Professor, Department of Speech and Hearing Science, The Ohio State University.
1980-83 Assistant Professor, Department of Linguistics, The Ohio State University.
1979-80 Visiting Assistant Professor, Department of Linguistics, The Ohio State University.
1975-76 Research Assistant, Phonetics Laboratory, Department of Linguistics, University of Chicago. Supervisor: Dale Terbeek.
1974-79 Production Assistant, Head of Computer Applications, The Astrophysical Journal, The University of Chicago Press.
1973-74 Research Assistant, Department of Linguistics, University of Chicago. Supervisor: Victor Yngve.