In 1928, Sham´baugh et al. reported the statistical analysis, according to audiometric and vestibular results with 3,120 deaf-school children and recently, Sandberg and Terkildsen (1965), and Swisher and Gannon (1968) also studied about the comprison of auditory and vestibular response with hearing impaired children.
In Korea, R.S. Hall, a missionary methodist began to educate two blind girls in 1898. At that time lack of education for these handicapped children made the special education developed slowly, in spite of its long hisfosy.
At present, there are 33 special schools, in Korea with 4,170 students: and more than half of these are hearing impaired. However, the Kyong Buk Education Committee estimated that there are more than 28, 000 ´hearing impaired children in Korea. With above data it is quite clear that only a part of them are receiving special education.
Now, there are little study in audiological aspect in Korea, so author studied about the history of illness, audiological and vestibular response with 607 deaf-school children, and the following results were obtained.
1. Hearing impairment occurred in in most cases before 3 years of age.
2. Causes of hearing impairment were genetic in prenatal period (22.7%), meningitis and measles in postnatal period (respectively 3.1%) and unknown (23.9%).
3. Types of hearing impairment were more than 90% of sensorineural type and less than 10% of mixed type, and no case of conductive type hearing loss.
4. Curvature of audiogram was descending, horizontal, basin etc. in descending order.
5. Degree of hearing impairment was more than moderate, and mostly profound hearing loss according to Goodman´s classification.
6. Air-bone gap of low frequency (250~500 Hz) was present in more than half and residual hearing was present in 25.3% among cases of no response on speech range.
7. Sppech reception threshold could not check in most cases and discrimination score was very poor, and speech detection threshold was about 20 dB better than pure tone average.
8. Caloric response was normal in 67.4% and diminished or absent in 32.6%, in genetic causes. was somewhat higher than other causes, and meningitis showed diminished or absent caloric response in all cases.
9. The more severe hearing impairment was present, the lower caloric response rate showed.
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