A substance called d-methionine can prevent noise-induced hearing loss.

A substance called d-methionine can prevent noise-induced hearing loss. This is a preventative measure, not restorative, but pharmacologists have essentially identified a substance that that's an urban construction worker's dream come true – pills to protect your ears from the acoustic torment of a jackhammer.
The medicine so far has shown promising results in protecting against hearing loss for cancer patients receiving a common chemotherapy drug known as cisplatin. The drug often causes hearing loss as a side effect.
D-met has been shown to be effective in reducing or preventing painful irritation in the lining of the mouth among patients receiving radiation therapy for oral cancer. The irritation can lead to fatal consequences because it can make it difficult or impossible for people to eat normally.
Neither of the treatment applications has undergone enough research in humans to receive FDA approval, however. More research is time-consuming and costly, and government grants take time to request, Campbell said.

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