Hearing loss affects 36 million Americans to some degree, often leaving them feeling isolated, but it has received little attention from the pharmaceutical industry - until now. Small firms have brought a handful of potential therapies to the development pipeline, and pharmaceutical heavyweights are taking notice, according to an article in Chemical & Engineering News (C&EN), the weekly magazine of the American Chemical Society.

The story states that the most common cause of hearing loss is loud noise, either from a single event like the bang of a firecracker or from chronic exposure, say daily listening to a cranked-up iPod. Although severe hearing loss can be treated with a hearing aid or cochlear implants, options are scarce for those suffering from milder damage. But there is growing interest to fill the void and to even develop preventative treatments. Several drug candidates have already advanced through early clinical testing in patients.

Lisa M. Jarvis, a senior editor at C&EN, notes that potential treatments generally focus on two areas: the inner ear, where sound is first perceived, and the central nervous system (including the brain), where sound is processed. Researchers are using small molecules and gene therapy approaches to target different components, from re-growing the ear's hair cells to controlling how nerve cells involved in hearing work. Small companies firing up the field such as Audion Therapeutics have shown enough success that deeper-pocketed firms Eli Lilly & Co., Novartis and Roche are backing them up.