many people, loss of hearing is irreversible.

对许多人来讲，听力的丧失是一件无法挽回的事。

For scientists trying to figure out what can be done about that, one answer may lie -- or swim, actually -- in freshwater aquariums².

对致力于研究这一问题的科学家来说，避免听力丧失的一个办法可以在淡水水族馆里找到。

About one of every 10 Americans suffers from hearing impairment, according to a survey conducted by the Better Hearing Institute, a nonprofit advocacy group. By far the most common cause of hearing loss is damage to the so-called hair cells in the inner ear as a result of excessive noise, certain illnesses and drugs, and simple aging. The problem is that once hair cells die, humans (like other mammals) aren't able to grow new ones.

非营利组织改善听力协会(Better Hearing Institute)的一项调查表明，大约每10个美国人中就有一人患有听力障碍。到目前为止，听力丧失最常见的原因就是内耳中所谓的“毛细胞”受到损害或者仅仅是因为上了年纪。过量的噪音以及某些疾病和药物会损害毛细胞。问题的症结在于毛细胞一旦死亡，人类(像其他哺乳动物一样)不能再生出新的毛细胞。

In recent years, a research team at the University of Washington in Seattle has been working on finding a way to resolve that problem in experiments involving the zebrafish, a common aquarium¹ denizen³. The zebrafish, like many aquatic⁴ creatures, has clusters of hair cells running along the outside of its body that help sense vibrations⁵ in the water, working in a similar way to hair cells in the human inner ear. But unlike humans, zebrafish are able to regenerate⁶ their damaged hair cells. Researchers hope their work can unlock secrets to protect human hair cells from becoming damaged and to stimulate⁷ the cells to regenerate.

近年来，华盛顿大学西雅图分校的一个研究团队一直在对一种水族馆里常见的观赏鱼类──斑马鱼进行研究，试图解决人类听力丧失的问题。和许多其他水生生物一样，斑马鱼在身体表面长有毛细胞。这些毛细胞的作用是探测水中的振动，其原理与人类内耳中的毛细胞相似。但是，与人类不同的是，斑马鱼的毛细胞在受损后还可以再生。研究人员希望他们的工作可以揭开谜底，保护人类的毛细胞免受损伤、并推动毛细胞的再生。

Hair cells, which took their name because under the microscope they look like cells with little hairs growing out of them, are an essential link in hearing. The filament⁸ hairs, or cilia, bend with vibrations caused by sound waves entering the ear. That induces the hair cell to create an electrical signal that is passed on to the auditory nerve and sent to the brain. Devices such as hearing aids, which amplify⁹ sounds, and cochlear implants¹⁰, which stimulate the auditory nerve directly, help people hear, but neither restores hearing to normal.

内耳中的这种细胞是人类听觉不可或缺的一环。之所以称为“毛细胞”，是因为它们在显微镜下看上去就像是在细胞外长出了绒毛。这些细细的绒毛，或者说纤毛，会因为声波进入耳朵以后产生的振动而摆动。这种运动会让毛细胞产生出一种能够经由听觉神经传给大脑的电信号。像助听器和人工耳蜗等设备都有助听效果，但都无法让人们的听力恢复到正常水平。助听器能够增加声音的强度，而人工耳蜗则会直接刺激听觉神经。