Abstract
Nine cases (18 ears) of juvenile sensorineural hearing loss were followed up for a period from 6 to 18 years (average 13.2 years). Hearing (average of 1-4kHz) was deteriorated in 13 ears. Sever deterioration (pure tone threshold elevation≥30dB) was seen in 8 ears. Mild deterioration (30dB≤pure tone threshold elevation>15dB) was seen in 5 ears. The rest of 5 ears had no remarkable threshold shift. There were two major patterns of the threshold evevation in the pure tone threshold. One was that the pure tone threshold elevated rapidly and largely following gradual and small threshold elevation. Another was that the pure tone threshold elevation was small and occurred gradually. These differences of threshold change may cause the differences of damage and/or vulnerability in their ears.
