Identifying and Quantifying Hidden Hearing Loss

Objectives: The purpose of this study was to identify and quantify a so-called ‘Hidden Hearing Loss,’ which is defined as degraded speech perception in background noise with no hearing threshold elevation. We hypothesized that 1) the loss of auditory nerve fibers, or cochlear synaptopthy, causes hidden hearing loss, and 2) the level of medial olivocochlear reflex (MOCR) reflects cochlear synaptopathy, thus predicting hidden hearing loss. Design: Eighteen subjects were recruited for this study and complained of difficulty understanding speech in environments with high noise levels. All participants completed behavioral and MOCR testing, followed by a speech-in-noise understanding test. A modified Noise Exposure Questionnaire (NEQ) was also completed by each subject in order to account for their noise exposure history. Results: The level of MOCR did account for variance in SiN accuracy. Age and pure-tone audiometry also contributed significantly to SiN accuracy, but in a redundant manner. However, noise exposure history did not seem to have any correlation to SiN understanding within this present study.