Swoboda H, Welleschik B
Universitätsklinik für Hals-, Nasen-und Ohrenkrankheiten Wien.
Laryngorhinootologie. 1991 Sep;70(9):463-9. doi: 10.1055/s-2007-998078.
Pure tone audiograms of 80 workmen with preexisting endogenous cochlear hearing loss were investigated over an average of 16 years (range 10 to 26) of occupational exposure to noise. Further hearing deterioration was moderate in the majority of cases more severe hearing losses more often affected the low tone range. The pure tone threshold 0.25 to 8 kHz remained unaltered in at least one ear in 24% of cases, in the high tone range 3 to 6 kHz in 51%. The average hearing loss was least at 3 kHz, followed by 4 kHz. The average hearing loss was somewhat greater in the initially better hearing ear. Differences between the two sides mostly developed in the high and the low tone region of trough-shaped thresholds, and in the low tone region of sloping thresholds. Hearing losses were greater when preexisting impairment did not exceed 30 dB HL than in preexisting damage over 30 dB HL. The average hearing losses for 0.5, 1, 2, 3 and 4 kHz were all lower than the respective average values for noise-induced hearing loss. Thus there was no evidence of increased noise susceptibility in endogenous cochlear hearing loss, either in comparison with controls or in a comparison of the sides or frequency ranges.
对80名已有内源性耳蜗性听力损失的工人进行了纯音听力图检查，这些工人平均有16年（范围为10至26年）的职业性噪声暴露史。在大多数情况下，听力进一步恶化程度为中度，更严重的听力损失更常影响低音范围。在24%的病例中，至少一只耳朵的0.25至8kHz纯音阈值保持不变，在高音范围3至6kHz中，这一比例为51%。平均听力损失在3kHz时最小，其次是4kHz。最初听力较好的耳朵平均听力损失略大一些。两侧之间的差异大多出现在谷形阈值的高音和低音区域，以及斜坡形阈值的低音区域。与已有超过听阈30dB HL的损伤相比，已有损伤不超过30dB HL时听力损失更大。0.5、1、2、3和4kHz的平均听力损失均低于噪声性听力损失的相应平均值。因此，无论是与对照组相比，还是两侧或频率范围之间的比较，均没有证据表明内源性耳蜗性听力损失会增加噪声易感性。
