First of all, hearing AIDS can amplify sound signals to ensure that users can feel the sound to the maximum extent. We all have the experience that it is not easy to hear too small a voice; Secondly, hearing AIDS can selectively amplify sounds of different frequencies according to the hearing loss of users (for example, for patients with severe high-frequency hearing loss, high-frequency multiple amplification; For patients with severe low-frequency hearing loss, amplify the low frequency more, and try to ensure that users can listen and hear clearly; Third, most hearing AIDS focus on amplifying language frequency to ensure language communication; Fourthly, with some special circuits, some hearing AIDS can amplify weak sound and limit the output of loud sound as needed. With the above functions, hearing AIDS can benefit most users.
However, hearing AIDS are not "all-purpose", can not be perfect, and can not solve all the problems of deaf patients. For example, the upper limit of the high frequency of normal hearing is 20000Hz, and the frequency response range of hearing AIDS can reach 8000Hz, which is very good, and rarely responds to sounds with frequencies exceeding 8000 Hz. In this sense, no matter how good hearing AIDS the deaf wear, they will not get better hearing than normal people. Therefore, it is completely unrealistic to think that hearing impairment will no longer occur when hearing AIDS are worn.