Identifying subclinical hearing problems

Abstract

Noise exposure and aging can cause subclinical hearing problems that are not identified with conventional audiometry. Potential clinical assessments were studied that could identify subclinical hearing deterioration: (1) Electrocochleography (ECoG); (2) Middle Ear Muscle Reflex (MEMR); (3) Extended High Frequency (EHF) thresholds (10–16 kHz); and (4) word recognition in noise. Sixty-one young, normal-hearing people were recruited. Each completed the four auditory assessments and the Life-Time Exposure to Noise Solvents Questionnaire (LENS-Q). ECoG and MEMR measurements were measured as a function of sound level using clinical equipment. Word recognition in noise was measured with a diotic, closed-set, 12-alternative spondees-in-noise test. It was hypothesized that normal-hearing individuals reporting more noise exposure would have slower growth of the ECoG measures and MEMR magnitudes with increasing levels. Individuals reporting higher noise exposure with the LENS-Q had significantly reduced MEMR magnitudes and smaller slopes, supporting the hypothesis. Gender effects were observed. No significant effect of self-report noise-exposure was seen with ECoG AP growth functions or SP/AP ratios, though modest age effects were observed. EHF thresholds were the only significant predictor of word recognition in noise. The results suggest that word recognition in noise, EHF audiometry, and MEMR could indicate subclinical hearing problems.