Chung D Y, Willson G N, Gannon R P
Audiology. 1983;22(2):199-205. doi: 10.3109/00206098309072783.
Usually equal noise exposure is considered to cause symmetrical hearing loss. In studying 1 461 audiometric records of claims for noise-induced hearing loss, it was found that 69 (4.7%) had a well-defined pattern of hearing loss in which only 2 kHz is asymmetrical by 20 dB or more. Audiograms of this type suggest that the cochlea of the worse ear has been damaged more extensively towards the apex. Of the 69 cases with a 2-kHz asymmetry, 82.6% had worse hearing thresholds in the left ear at 2 kHz. In 50% of the 69 cases, the asymmetry could not be accounted for even after the examination of their medical, occupational and nonoccupational histories. It is believed that the asymmetry at 2 kHz is a manifestation of a lateral difference in susceptibility to noise damage and that the left ear is the more susceptible one in the majority of cases.
通常认为，同等噪声暴露会导致对称性听力损失。在研究1461份噪声性听力损失索赔的听力记录时发现，69例（4.7%）有明确的听力损失模式，其中仅2千赫处的不对称性达到20分贝或更高。这种类型的听力图表明，较差耳朵的耳蜗向顶端的受损程度更广泛。在69例2千赫不对称的病例中，82.6%在2千赫处左耳的听力阈值更差。在这69例病例中，即使在检查了他们的医疗、职业和非职业病史之后，仍有50%的不对称情况无法解释。据信，2千赫处的不对称是对噪声损伤易感性的侧向差异的一种表现，并且在大多数情况下左耳更易受损。
