The Screening Level of Pure Tone Audiometry for Young Children

The aim of this study is to investigate the relationship between screening level of pure tone audiometry and back-ground-noise level. In the experiment I, the loudness of kack-ground-noise was measured ten quiet rooms in nursery schools and kindergartens selected atrandom in the city of Kanazawa. In the experiment 2, the thresholds (HL; JIS) for 0.25, 0.5, 1, 2, 4, 8kHz pure tones were measured in the presence of the four kinds of loudness levels (40, 45, 50, 55 phon dB (A)) of white noise. The subjects were 48 children aged from three to six (12 children in each age group). The following results were obtained: 1. The loudness levels of back-ground-noise of ten institutions were below 40 phon except intermittent large noise. 2. Asloudness of back-ground-noise was increased, the mean thresholds of each group at each frequencies tended to grow significantly. 3. The mean threshold was mainly increased at 1kHz. 4. The noise level, in which the mean threshold added to three times of SD was within the limits of 20dB (JIS), was below 40 phon in three and four years of the age groups, and below 45 phon in five and six years. 5. From the above-mentioned results and the fact that mild conductive hearing loss was much common in the pre-school children, it was postulated that the screening level of 20dB (JIS) of pure tone audiometry was appropriate.