On her arm.

Another squicky warning. If you don't want to see an ear growing out of a person's forearm, don't click on the link.

Byrne and a team of doctors harvested cartilage from Walter's ribs, shaped it into an ear and placed it under the skin of her forearm. Nourished by surrounding blood vessels, the new ear developed skin of its own and, after four months, the surgeons removed it. Next, they attached it to blood vessels in Walter's head, sculpting tissue to affix it permanently in March of this year.

Since March, Walter's surgeons have focused on the more cosmetic aspects of the process, shaping and sculpting the new left ear to match the right one as much as possible. Though she still needs to undergo a few more surgeries to complete the process, Walter's hearing has been restored with the help of a special hearing aid.

Gross, but amazing. So, yay science. I'm glad it exists, but I don't want to have to see it.