Is it reasonable to use 1 and 8kHz anchor points in the medico-legal diagnosis and estimation of noise-induced hearing loss?

摘要

BackgroundIn the United Kingdom, use of 1 and 8kHz as anchor point frequencies has been recommended for the medico-legal diagnosis and estimation of noise-induced hearing loss. There appear to be four assumptions behind the use of 1 and 8kHz anchor point approach: (i) The frequencies of 1 and 8kHz are not damaged by noise; therefore, the measured hearing thresholds at the said frequencies solely reflect age-related hearing loss, even in the noise-exposed; (ii) The hearing thresholds at 1 and 8kHz are a valid predictor of the likely age-related hearing loss thresholds at the other frequencies; (iii) Age and noise damage are always completely additive; (iv) Individual's susceptibility to age and noise damage is not proportionate. Doubts have been expressed in the medical circles about the legitimacy and validity of their use as anchor points.