1. Rehabilitation Engineering Research Center on Alternative and Augmentative Communication, State College, Pennsylvania, USA
2. Koester Performance Research, Asheville, North Carolina, USA
3. Department of IRSE, Madonna Rehabilitation Hospital, Institute of Rehabilitation Science and Engineering, Lincoln, Nebraska, USA
4. Department of OT, Occupational Therapy Department, Madonna Rehabilitation Hospital, Lincoln, Nebraska, USA
5. Communication Sciences and Disorders Department, State College, Pennsylvania State University, Pennsylvania, USA