Organic thresholds and functional components in experimentally simulated exaggerated hearing loss.

Abstract

Previous studies on the relationship between functional overlays and underlying organic hearing levels in nonorganic hearing loss (NOHL) have relied upon the clinical resolution of the nonorganic portion of the loss. This study involved the first use of subjects with sensorineural losses in a simulated NOHL experiment. This is important because most adults with NOHLs have underlying sensorineural losses. Different configurations of the experimentally simulated functional components (the difference between the exaggerated and real thresholds) as a function of frequency were associated with (a) normal hearing; (b) losses becoming abruptly worse at 4000 Hz, and (c) sloping losses, respectively. Thus, the simulation data corroborate the observations made using clinical patients with resolved NOHLs, and provide further support for the notion that these patients typically employ a strategy involving the use of an internalized loudness-based anchor on a within-ear basis to generate their exaggerated audiograms. Moreover, the outcome of this study reveals the limitations of restricting the subjects used in simulated NOHL experiments to normal hearing individuals, and highlights the importance of using hearing impaired groups in future experimental simulations of nonorganic hearing losses.