Audiology is a science that studies people's hearing function, diagnosis, treatment and rehabilitation of hearing impairment and the harm of environmental noise to people's ears. The research scope of audiology is very wide, with the following branches: basic audiology, experimental audiology, clinical audiology, pediatric audiology, industrial audiology, forensic audiology and so on. People are more interested in clinical audiology, including diagnostic audiology and rehabilitation audiology. The former mainly includes auditory function test, test result analysis and auditory function state evaluation, which helps otology, neurology and surgery to find lesions and provide suggestions for the diagnosis and treatment of speech-language disorders. The latter mainly includes drug therapy, hearing reconstruction surgery, hearing aid application and listening and speech training. Audiology is a new major set up by Chinese universities in the new century to meet the needs of 60 million hearing-impaired people in China. This subject studies the physiology, pathology and hearing rehabilitation methods of listening, and it is an interdisciplinary subject of biological science, electroacoustics, linguistics and medicine. In the United States, audiologists have become one of the top ten most popular occupations.