International standard for deafness

International standard for deafness

The so-called deafness refers to the hearing loss or hearing loss caused by abnormal sound transmission and sensory function of the auditory system, which is called deafness.

The frequency of sound that humans can hear is20-20000HzChildren can hear high frequencies24000HzLeft and right, the language frequency zone is500-3000Hzbetween. Because humans have different recognition and intelligibility to language and pure tone acceptance mechanism, the two can be inconsistent. Sometimes the result of pure tone audiometry shows that the hearing loss is not heavy, but the language is not understood, the sound is incomprehensible, mostly the central side of the lesion; sometimes the pure tone is displayed3000HzThe above frequency loss is heavier, and the frequency loss under it is very light or normal, and it has no effect on listening to ordinary conversation. Therefore, the degree of deafness, the location and nature of the lesion must be determined through various primary and objective hearing tests. As far as the current situation is concerned, the grading standard for hearing loss, which is hearing impairment, is mostlyWHO (1997)The standard recommended by the Geneva conference, based on pure tone audiometry, frequency (500,1000,2000,4000HzAverage hearing threshold, an increase from the previous standard4000HzThe hearing threshold fully considers the high-frequency hearing loss of hearing-impaired people and has certain clinical value.2006The second national sample survey of disabled persons, reference to the standard of hearing disabilityWHO (1997)Standard and previous1986The annual disability standard has been revised. The details are as follows.