Many, probably most, of us learned the mechanism for hearing in biology class. Basically, sound waves vibrate the eardrum, causing tiny bones to move, and so on until the vibrations reach hairs in the cochlea. What hasn't been known is how the vibrations are then converted to electrical impulses to be interpretted by the brain. Any biochemist would have been confident guessing that it was a protein, but noone knew which one. Scientists at Harvard appear to have finally found it. Mice and zebrafish where a protein called TRPA1 has been blocked from the tips of these hairs are deaf. When the hairs move, TRPA1 opens ion channels. These moving ions are an electrical impulse that the brain interprets. It turns out that this response is faster than that of any other sense.

After decades of searching for it, the protein appears to have been found, but more testing is necessary to determine if this is the cause of natural hearing loss in humans and, if so, how this knowledge can be applied.

That is amazing! So it is possible that they may only need to find a way to introduce that protein to hearing impaired humans, and they can cure deafness?

Not all deafness, though, right? Aren't there other causes of deafness, like damage to the ear drum and things like that?

Right. This couldn't repair physical damage, but there are already significant treatments for that.

The first step is to find out whether naturally deaf people are deficient in the protein (the mice were artificially made deficient). If so, the next step is to find a way to overcome this deficiency (which will likely involve determining why they are deficient - is there another chemical blocking it? Is there an error in the part of the genetic code coding for the protein or a part coding for the modifications made to the protein after it is made?) Just injecting the protein is an unlikely solution because it won't be able to get inside the cell, but there may be some treatment to encourage the deaf person's own cells to make the protein.

That is really amazing. I wonder, if they find that it is a chemical blocking the protein, how will they correct that? I can't wait to see what comes of this!

That would be a bit too much conjecture for me. It would depend on the mechanism that the chemical (if that is the/a cause) is using to block the protein's action.