As we all know, we call the ability of the auditory organ to perceive sound as hearing, and the clinical evaluation of good or bad hearing is to find a standard that can be regulated by a number, and this is the role of “hearing threshold”. The patient’s hearing loss is more than 30 dB, that is, the hearing threshold of the frequency has increased by 30 dB, can be diagnosed as deaf. When the noise is very strong and the top of the spectrum changes a lot, jumping up and down, etc., the hearing threshold will rise when the noise damages the ear. So, how should the differential diagnosis of rising hearing threshold be made in patients? The following is a brief introduction: a. Hearing impairment: Hearing impairment refers to the congenital or acquired causes, resulting in structural defects of the auditory organs, or partial or total functional impairment, resulting in difficulty in hearing or recognizing sound; the identification criteria are as follows: 1. After receiving a conscious pure tone hearing examination, the superior ear speech frequency hearing of more than twenty-five decibels. 2.If you are unable to undergo the pure tone hearing test in the preceding paragraph, you will be identified by other hearing tests. Second, auditory fatigue: when you go into the strong noise environment, you will feel the ear uncomfortable, stop a period of time out, you will feel the hearing becomes dull, the original can hear the slight sound also can not hear, this is because your hearing threshold upward, thus leading to your hearing loss. But as long as you leave the noise environment to rest for a period of time, human hearing will gradually return to its original state, this phenomenon is called temporary hearing offset, also known as auditory fatigue. It is only a temporary physiological phenomenon, the auditory organs are not damaged. If one works under strong noise conditions for years and years, the inner ear auditory organ is often stimulated by strong noise, this auditory fatigue will be fixed and will not return to normal, and a permanent hearing loss or hearing threshold shift is produced. This phenomenon is called noise-induced deafness.