1. The Minnesota Ear, Head and Neck Clinic; International Hearing Foundation, Minneapolis, MN; and Taipei Medical College Hospital, Taiwan.
2. The Minnesota Ear, Head and Neck Clinic; Department of Otolaryngology, University of Minnesota Medical School; and International Hearing Foundation, Minneapolis, MN.
3. Department of Otolaryngology, University of Minnesota Medical School.
4. The Division of Biostatistics, University of Minnesota School of Public Health, Minneapolis, MN.