老年性聋和噪声暴露都可引起永久性听器损害,但老年性聋的病变涉及整个听觉系统。典型的噪声性聋的听力图呈4000 Hz凹陷,而老年性聋的听力图则随其不同类型而异。多数作者认为噪声暴露和老年这两个因素,在对听力影响的作用上是相加的;也有人认为是协同性的。然而这两个因素虽是相加的,又可以不相加。例如当某一区域内的感觉细胞完全破坏后,再有其它破坏 Senile deafness and noise exposure can cause permanent hearing loss, but senile deafness affects the entire auditory system. A typical noise-induced deaf audiogram shows a 4000 Hz depression, whereas the audiogram of senile deafness varies from one type to another. Most authors consider the two factors, noise exposure and aging, additive in the effect on hearing; some consider it synergistic. However, although these two factors are additive, they can not add up. For example, when the sensory cells in a certain area are totally destroyed, there is another damage