Deafness refers to the hearing impairment or hearing loss caused by the acoustic and auditory dysfunction . There are many types of deafness , with mild or severe hearing loss , the course of which can be either long or short .
耳聋是指听觉系统的传音感音功能异常所致听觉障碍或听力减退，耳聋有许多种类型，听力损失有轻有重，病程有长有短。
hearing impairment/loss