WHO (WHO) classification criteria for hearing impairment and its daily performance

In general, humans perceive sounds from 20HZ to 20kHZ, from 0dB HL to 130dB HL. When the sound reaches or exceeds 130 dB HL, people feel earache and discomfort. Based on the frequency of sound and the ability of people to perceive sound intensity, the World Health Organization has developed a grading standard for hearing impairment. It is recommended that the hearing impairment be divided into four levels based on the average pure tone hearing threshold of 0.5, 1, 2, and 4kHz: 26~40dB HL is mild, 41~60dB HL is moderate, and 61~80dB HL is severe. ≥ 81dB HL is extremely heavy. Hearing disability is a type of severe permanent hearing disorder that is classified according to the functional impact of hearing impairment on people. When the severity of hearing impairment reaches the legal standard and continues to affect the daily activities and social functions of the patient, it can be considered as a hearing disability.

In addition, Children are at a critical stage in speech and language development, and listening to health is especially important. Therefore, some foreign scholars suggest that as long as children’s hearing loss is higher than 15dB HL or hearing loss in a single ear, timely attention and intervention should be given. To emphasize the importance of children’s hearing health, the World Health Organization defines adult hearing disability as the standard for hearing disability: XIUX, 0.5, 1 and 2 kHz 4 frequency permanent non-hearing threshold average ≥ 4dB HL Children’s hearing disability is defined as better ears 41, 0.5, 1 and 2 kHz 4 frequency permanent non-hearing threshold average ≥ 4 dB HL.