Threshold of hearing (0.125-20 kHz) in children and youngsters.

Pure-tone air-conduction audiometry has been performed in three groups of children and youngsters aged 10, 14 and 18 years old. The complete frequency range of 0.125 to 20 kHz was measured, and number of different questions were raised. Firstly, the hearing threshold in the conventional frequency range was compared to the international standard ISO 389. Significant differences from ISO zero were found for all groups and at all frequencies of 0.125 to 8 kHz. Secondly, possible noise damage, shown as dips in the audiograms at 3, 4 or 6 kHz was examined; and thirdly, high-frequency (8-20 kHz) sensitivity between groups was compared. Only a few audiograms, the majority being in the youngest age group, were found to be a result of possible noise damage, and in the extra-high-frequency range, a systematic decrease in sensitivity was found for the two older groups compared to the 10-year-old children at frequencies higher than 14 kHz.