Schmucker C, et al. - Researchers performed this review of the epidemiological literature to estimate the prevalence of hearing loss in children and adolescents residing in Germany as an illustration for a Western country. They identified 11 reports by exploring Medline, Web of Science, Cochrane Library, ScienceDirect and LIVIVO as well as via manual search and exploration of ongoing investigations and/or not yet published data in clinicaltrials.gov. Despite a decline in the prevalence estimates, it was challenging to produce a comprehensive and coherent set of estimates when the threshold was increased because of the observed clinical heterogeneity including the disparity in age, the research setting, the definition of hearing loss and the evaluation method. They also noted that impaired representativeness (external validity) was common because the estimates lacked currentness (ie, referring to former West Germany) or selected (patient) data and may not be typical for a more general population. Concerning hearing loss, public awareness of its high prevalence is increased by the findings. Issues related to epidemiological research were also emphasized in this study.