Perstimulatory suprathreshold auditory adaptation in children.

The decline in loudness of a pure tone was used as a criterion of perstimulatory suprathreshold auditory adaptation. The testing technique consisted of continuous binaural balancing of a steady adapting stimulus with an interrupted comparison tone of equal frequency, the pulse and pulse intervals being of 200 msec duration. The measurements were carried out in the majority of cases at 60 dB sensation level for frequencies 2 000 to 4 000 Hz. In normal-hearing test subjects younger than 15 years, as compared with adults, adaptation was of a different character. It could be demonstrated only in a few cases, which were almost without exception among the oldest in their group. The amount of adaptation in the group of 15-18-year-old subjects did not differ statistically from that of the adult persons, even though the adaptation was slight in 25% of the cases. The lacking or slight adaptation was noticeable also in all types of hearing disorders in the young patients.