Acknowledgments
The authors would like to thank all those who took part in this study.
Disclaimer statements
Contributors Kristin M. Sjoberg conceived of the project, collected data, contributed to manuscript.
Ms Virginia D. Driscoll assisted in project development, including writing tests used in study, collected data, assisted with manuscript preparation. Dr Kate Gfeller supervised Ms Sjoberg in project development, provided collaboration, assisted with manuscript preparation. Ms Anne E. Welhaven completed statistical analyses and assisted in results of study. Dr Karen Iler Kirk provided research tests used, collaborated with Dr Gfeller and Ms Sjoberg, assisted in manuscript preparation. Dr Lindsay Prusick assisted in test creation and access.
Funding This study was supported by grant 2 P50 DC00242, RO1 DC012082-10, and 5 RO1 DC008875-06 from the NIDCD, NIH, and the Lions Clubs International Foundation, the Iowa Lions Foundation.
Conflicts of interest The authors declare no conflicts of interest.
Ethics approval Our research project requested, and received, approval from the Humans Subjects Office at the University of Iowa.