I believe Dr. Christopher called it the Ear and Nerve formula.
The easiest and best thing to do would be to buy MH's ear product.
Otherwise you would have to buy the herbs seperately from, say, here:
mountainroseherbs.com
and read up on how to make a tincture with herbs. A tincture is a concentrated form of the steeped herbs and then preserved in a alcohol solution. Sorry, haven't tried it yet, but seeing as I'm slowly going more deaf, I plan on experimenting one of these weekends.
Try to read more about it here, look under ailments "deafness." herballegacy.com
I know you're not trying to cure deafness, but it can help rebuild the nerves in the ear.