Indicators of noise damage: Association between lifetime noise-exposure questionnaire, high-frequency audiogram, and categorical loudness scaling

Some effects of noise-induced hearing loss may be evident at the neural level, such as cochlear synaptopathy but not necessarily manifest at the audiogram level (0.25–8 kHz); although indicators of early noise-induced hearing loss may be observable at higher audiometric frequencies. The current study compares two populations; both populations have normal hearing up to 8 kHz; however, one population has minimal lifetime exposure history for high-level noise, and the second population has previous and ongoing significant noise-exposure history. The individual‘s experience of noise exposure is assessed with a structured interview approach eliciting the level and duration across a range of noise exposure activities. Categorical loudness scaling (CLS) is used to quantify individual loudness perception. The slope of the low-level portion of the CLS function may be associated with increasing audiometric threshold. Different fitting procedures for the CLS were evaluated. The CLS slopes were compared with audiograms (0.25-16 kHz) as well as two evaluations of uncomfortable loudness levels (ULL); one using the traditional audiometric tonal stimuli and the second using the CLS broadband noise stimuli. This study investigates the extent to which noise damage can be deduced from a lifetime noise-exposure questionnaire, high-frequency audiogram, and categorical loudness scaling data.