Progressive, irreversible hearing loss can result from radiation therapy and platinum-based chemotherapy drugs such as carboplatin and cisplatin. The drugs damage the hair cells of the inner ear, making the ear less responsive to sound waves. A 2010 study by German scientists showed that hearing loss is worst among patients who were younger when they were diagnosed, probably because they have taken in higher doses of platinum drugs over their lives. Children and adolescents receiving platinum-based chemotherapy should have regular audiometric follow-up exams, especially for frequencies above 2 kHz, even long after treatment has wrapped up, the researchers said. Cochlear implants are one way to remedy hearing loss that becomes serious.