In the past, the wearing of hearing aids had a lack of understanding: (1) deafness in one ear, the other ear is normal or available hearing, that do not need to wear; (2) mixed deafness hearing aids have a certain degree of help; (3) sensorineural deafness to improve the hearing poor; (4) hearing loss is not heavy do not need to wear a hearing aid. In fact, no matter which kind of deafness, sensorineural deafness, conductive deafness or mixed deafness, whether it is unilateral or bilateral deafness, bilateral hearing symmetry or asymmetry can be considered to wear different types of hearing aids. The advantages of wearing hearing aids binaurally include: (1) help to localize the sound source and distinguish the direction of the sound source; (2) make the sound sound three-dimensional, richer sound; (3) have a noise reduction effect, in the noisy environment, it can improve the ability to recognize speech and selective listening ability; (4) eliminate the head shadow effect, can avoid the impact of the head shadow caused by monaural hearing; (5) good integration function, due to the binaural effect, so the loudness of the sound is increased. (5) Good integration function, due to the binaural effect, the loudness of the sound is increased. Some people are concerned about the long-term use of hearing aids will have an adverse effect on the residual hearing, but worsening deafness, this view is similar to myopia and myopia for fear of deepening myopia and do not dare to wear glasses is a similar misunderstanding. According to research, no matter what kind of deafness, as long as the use of appropriate, will not be worsened by long-term use of hearing aids. Long-term habit of wearing a hearing aid people, leaving the hearing aid when they feel their hearing seems to be less than before, in fact, this is a “pseudo-deaf” performance, medically known as “functional deafness”, and is not a real deterioration of hearing. Some patients wearing hearing aids may also have a masking effect on the original tinnitus, so that the tinnitus symptoms to reduce or disappear. There are a few people in the use of the process of hearing loss, this may be other diseases itself or the body continues to progress in the cause of aging, and hearing aids have little to do.