1. Epidemiology and Statistics Program; National Institute on Deafness and Other Communication Disorders, National Institutes of Health; Bethesda Maryland
2. Department of Otolaryngology-Head and Neck Surgery; The University of Texas Health Science Center at San Antonio; San Antonio Texas
3. Hearing Loss Prevention Team, Engineering and Physical Hazards Branch; National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention; Cincinnati Ohio
4. Stephenson and Stephenson Research and Consulting, LLC-West; Forest Grove Oregon U.S.A.