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“Hearing music with only one ear engages only half of the brain. Hearing Clair de lune with two ears was like the difference between a live and a dead body: the form was the same, but the experience was oh so different.”
On January 24, 2008, I sat in my audiologist’s office waiting to have my new right ear turned on. For the first time in 30 years, I was about to hear in stereo again.
I’d dealt with hearing loss all my life, because my mother got rubella when she was pregnant with me. I had used hearing aids since the age of three, but gave up on the right ear in the 1980s after it gradually died. In 2001, the left ear died too. During a business trip in Reno, things began to sound fuzzy. After four hours I canceled my meetings and stumbled back to San Francisco, shocked, dizzy, and totally deaf.
The cause of what happened that day in 2001 is unknown, but the general reason for my deafness was clear. The inner ear, called the cochlea, is a pea-sized, snail-shaped organ lined with thousands of tiny hair cells that vibrate when sound hits them. The hairs trigger nerve endings, which send information to the brain. Most cases of deafness are caused by damage to the hair cells precipitated by things such as noise or viral infections. Before 2001 I had enough hair cells remaining in the left ear to benefit from the amplified sound of a hearing aid. Then, for some reason, they too were destroyed. My auditory nerves remained intact, but there was nothing to trigger them.
The nerves could be triggered, though, by a device called a cochlear implant. In September 2001, a surgeon at Stanford Hospital drilled an inch and a half into my head and threaded 16 tiny electrodes into my left ear’s cochlea. The electrodes were controlled by a computer chip embedded in the surface of my skull underneath the scalp. After a few weeks of healing, I got an external computer that sent it data. It sat on my ear, looking like a hearing aid, and radioed a megabit of data per second to the chip in my head.
I had only one ear done in 2001 because it was the standard practice at the time. It had worked out well: I was able to use telephones, listen to the radio, and converse at parties. But with only one ear, I still had significant limitations. I couldn’t tell where my students’ voices were coming from. A sound coming from a person’s right side will reach the left ear a few hundredths of a second later. The brain has neurons specifically designed to compare the two ears and detect time differences, giving rise to the sensation of it’s over there.
With one ear, I had to rubberneck until I found who was speaking. It took me a second or two to do that, hence I lost the entire first sentence and apologetically had to ask the student to start over. In 2006, after another frustrating semester, I quit teaching. I went to my surgeon and said, “I think it’s time to go bilateral.”
At first my insurer, Aetna, wouldn’t cover getting a second ear. Of about 100,000 implant users worldwide, about 3,000 of them had gone bilateral. (One implant costs about $50,000; getting two simultaneously costs somewhat less than twice as much, since there is only one surgery.) Drawing on that population of 3,000, many studies had come out since 2001 confirming the benefits of having two functioning ears. In late 2007 Aetna changed its policy, joining a growing list of insurers that cover bilateral implants.
On December 17, I had my right ear implanted. The surgery was amazingly easy—much easier than the first time. It took the surgeon only 43 minutes. I went in at 8 a.m. and was back home by 2 p.m. Instead of being groggy for three days, as I was with the first ear, I stuffed myself with omelettes that night and went to the supermarket two days later.
