Niwa H, Yanagita N
Department of Otorhinolaryngology, Nagoya Univerisyt, School of Medicine.
Nihon Ronen Igakkai Zasshi. 1990 Sep;27(5):545-9. doi: 10.3143/geriatrics.27.545.
Presbyacusis is senescence in the auditory system. Currently, the etiology of presbyacusis is thought to be mainly due to environmental noise and arterial sclerosis. Cumulative effects of social noise influence the auditory function gradually. Sclerotic change of arteries in the brain occurs along the total auditory pathway. Histopathological findings reveal characteristic changes in all parts of the auditory pathway in elderly persons. Alterations include thickening of the ear drum, sclerotic change of the ossicles joint, decreasing number of hair cells, degeneration of the eighth nerve and of the neurons in the auditory center. Pure tone audiograms show gradually progressive sensorineural hearing loss at high frequencies due to lesions characteristic of senescence. During the 30's the threshold at 8 KHz increases a little, but in the 60's the pure tone threshold increases over all frequencies. The maximum speech discrimination parallels the drop in the pure tone threshold level. In contrast to the normal speech discrimination score, the speech discrimination score using frequency distorted words is very low in senile persons. There is no known therapy for presbyacusis. Hearing aids compensate hearing impairment to some extent, but patient's adaptation to hearing aids is undetermined.
老年性聋是听觉系统的衰老。目前，认为老年性聋的病因主要是环境噪声和动脉硬化。社会噪声的累积效应逐渐影响听觉功能。脑内动脉的硬化性改变沿整个听觉通路发生。组织病理学研究结果揭示了老年人听觉通路各部分的特征性变化。改变包括鼓膜增厚、听小骨关节的硬化性改变、毛细胞数量减少、第八神经和听觉中枢神经元的变性。纯音听力图显示，由于衰老特征性病变，高频处逐渐出现进行性感音神经性听力损失。在30多岁时，8千赫兹处的阈值略有增加，但在60多岁时，所有频率的纯音阈值均升高。最大言语辨别力与纯音阈值水平的下降平行。与正常言语辨别分数相比，老年人使用频率畸变词的言语辨别分数非常低。目前尚无已知的老年性聋治疗方法。助听器在一定程度上可补偿听力损害，但患者对助听器的适应性尚不确定。
