1980 年 23 巻 3 号 p. 127-135
For the purpose of auditory training in children or infants with nerve deafness, it is very important to use the hearing aids as earlier as possible, and then also essential to find out the real ability of hearing. However, it is relatively difficult to get the hearing threshold of the impaired children or infants, because the results of response do not necessary mean the real sensitivity.
These children were observed for a long period, and their threshold were discussed from many viewpoints, for example, the types or grades of hearing level and frequencies (0.5kHz, 1kHz, 2kHz and 4kHz). The results were as follows.
The threshold of hearing was tended to decrease until the children grew up to 8 to 10 years old, particularly in 0.5kHz. This decreasing tendency was observed up to the age of 8 to 9 years at 1, 2 and 4kHz, and about 12 years old at 0.5kHz. Therefore, the reliable threshold of hearing in children should be determined after twelve years of age.
In addition, the increasing tendency of the hearing threshold was observed not only in high frequency response (4kHz), but also in middle ones (1kHz and 2kHz).