A number of the problems that cause hearing loss for our patients can’t be reversed which is quite frustrating for our hearing specialists. One of the principal causes of hearing loss, for example, is damage to the tiny hair cells in our inner ears that vibrate in reaction to sounds. Our sense of hearing is the result of these vibrations being translated into electrical energy and transmitted to the brain for interpretation.
These hair cell structures must be very small and sensitive to do their jobs correctly. It is precisely because they are very small and sensitive that they are also easily damaged. Aging, certain medications, infections or prolonged exposure to high-volume sounds (resulting in noise-induced hearing loss) are all potential sources of damage. The hair cells in human ears can’t be regenerated or “fixed” after they are damaged or destroyed. Therefore, hearing professionals and audiologists have to treat hearing loss technologically, using hearing aids or cochlear implants.
If humans were more like fish or chickens, we’d have other options available. That may sound like an odd statement, however it is true, because – unlike humans – some fish and birds can regenerate inner ear hair cells, and thus regain their hearing after it is lost. For reasons that aren’t fully understood, zebra fish and chickens have the ability to spontaneously duplicate and replace damaged inner ear hair cells, and thus achieve full functional recovery from hearing loss.
Bearing in mind that this research is at a very early stage and has as yet produced no proven benefits for humans, some hope may be on the horizon in the treatment of hearing loss as a results of research called the Hearing Restoration Project (HRP). Financed by a non-profit organization called the Hearing Health Foundation, this research is presently being carried out in 14 different laboratories in the U.S. and Canada.What the HRP scientists are trying to do is isolate the compounds that allow this replication and regeneration in animals, with the ultimate goal of finding some way of stimulating similar regeneration of inner ear hair cells in humans.
The research is painstaking and difficult, because so many different molecules either help with replication or hinder hair cells from replicating. But their hope is that if they can isolate the molecules that enable this regeneration process to happen in fish and avian cochlea, they can find a way to enable it to happen in human cochlea. The scientists in the various HRP labs are taking different approaches to the challenge, some pursuing gene therapies, others working on the use of stem cells, yet all share the exact same objective.
Our entire staff extends to them our best wishes and hopes for a great success, because nothing would delight us more than being able to fully cure our clients’ hearing loss.