1. VA Portland Health Care System, VA National Center for Rehabilitative Auditory Research, Portland, OR, USA;
2. Department of Otolaryngology/Head and Neck Surgery, Oregon Health & Science University, Portland, OR, USA;
3. Department of Otorhinolaryngology, Division of Audiology, Mayo Clinic, Rochester, MN, USA;
4. Walter Reed National Military Medical Center, National Military Audiology and Speech Pathology Center, Bethesda, MD, USA;
5. Department of Otolaryngology, Yale University School of Medicine, New Haven, CT, USA