To evaluate and describe results of aetiological investigations offered to a population level cohort of babies who had confirmed permanent hearing loss after they either (i) failed universal neonatal hearing screening or (ii) passed newborn screening but were detected with a permanent hearing loss in early childhood.

中文翻译：

---

人口水平的永久性儿童听力损失的病因

评估和描述向人口水平的婴儿群体提供的病因调查结果，这些婴儿在 (i) 未能通过通用新生儿听力筛查或 (ii) 通过新生儿筛查但在早期发现永久性听力损失后已确认永久性听力损失童年。