条件詮索反射聴力測定 (COR-audiometry) による乳幼児の正常聴力について

抄録

Hearing acuity of 420 normal children aged under 4 years was measured by means of COR-audiometry. The rate of successful test in each age group was as follows:
under 1yr. 39.4 per cent
1yr. to 1yr. 5mo. 79.4
1yr. 6mo. to 1yr. 11mo. 86.8
2yr. to 2yr. 5mo. 81.6
2yr. 6mo. to 2yr. 11mo. 91.9
3yr. to 4yr. 64.0
By using the modified method introduced by Ogiba, this rate of successful test was increased to 83.3 per cent for infants 8 to 11 months of age. Consequently, the majority of the tests for infant children under 1 year of age were administered by using Ogiba's modified method.
Average hearing threshold in each age group of each 50 examinees is indicated in the following table.
under 1yr. 27.4db
1yr. to 1yr. 5mo. 20.3
1yr. 6mo. to 1yr. 11mo. 16.2
2yr. to 2yr. 5mo. 13.7
2yr. 6mo. to 2yr. 11mo. 12.6
The tendency of the hearing acuity of small children to get closer to 0db as the child becomes older was clearly seen.
Comparison of the hearing thresholds obtained in the first and the second tests revealed the fact that the difference between the two thresholds fell within the limit of 5db in 90.2 per cent of the total examinees tested. Age difference in the test-retest variance was not recognized.