Hearing thresholds for "otologically normal" adults from the National Health and Nutrition Examination Surveys 2011-12 and 2015-16.

Abstract

Hearing threshold levels (HTLs) get worse with advancing age in adults. Publications of nationally representative data from U.S. adults have been confined to HTLs from unscreened individuals. ISO 7029:2017 provides equations for the hearing loss of adults of various ages. Equations were generated from a synthesis of international studies of HTLs for "otologically normal" or screened adults. No nationally representative data for screened U.S. adults were included in the ISO synthesis. This study investigated three different levels of screening rigor, referred to here as Screened, Screened+, and Screened++. Median HTLs are provided for Screened (N = 1545) and Screened++ (N = 795) groups from the National Health and Nutrition Examination Surveys for 2011-12 and 2015-16, the two most recent surveys of adults from 20 to 69 years of age with audiograms. Median HTLs from the Screened and Screened++ groups differed slightly between the sexes, were not affected by race/ethnicity, and increased substantially with age. For young adults, there were no differences in HTLs between screened (any level) and unscreened adults, but such differences in HTLs increased with advancing age, especially at higher frequencies. The default power-function model from ISO 7029:2017 did not provide a good description of the median age-associated HTLs from screened U.S. adults.