Low level. There are five levels of musical hearing loss.

1. First-degree mild deafness refers to the difficulty in hearing low-pitched conversations, usually 26 to 40 decibels.

2. Second degree moderate deafness, generally speaking difficulty, hearing threshold is generally 41-55 decibels.

3. The third degree is moderate and severe deafness. You must speak loudly to speak clearly, usually 56 to 70 decibels.

4. Fourth degree severe deafness requires speaking loudly in the ears. The hearing is generally around 70 to 90 decibels.

5. The degree of fifth degree deafness is high, the ear cannot hear, and the hearing threshold is generally greater than 90 decibels.