One recent afternoon in the midst of my daily exercise routine, approximately 5000 cilia in my left inner ear – those tiny hairs that convert vibration into electricity and send it to the brain as the perception of sound – went suddenly offline. At least that’s the way it felt, as though someone had abruptly pulled the plug on a number of sound frequencies in that ear.  I could still hear, my right ear was normal, but in the left ear sounds had become tinny, and there was a high-pitched background buzz that I associated with a blown speaker in an overtaxed stereo system.

At first I thought it might be congestion, a symptom of the summer allergies that pop up and recede as the local flora works its way through its life cycle.  But there was none of the muffled feeling that I associate with an allergic reaction, nor the inflammation or trapped liquids in the outer or middle ear that I’ve experienced after innumerable scuba dives or lengthy plane flights. This felt more like a “wiring” problem, something distinctly neurological.  Still, the onset was so sudden that I hoped it might go away just as quickly, and went about my day.

The next day was worse. It seemed that more frequencies had dropped offline, and the tinnitus – that white noise that has no source in the real world — had increased.  This put me on high alert, in part because of my experience with a long-time colleague’s hearing issues.

In our forties, Bob and I had been vacationing with our spouses in the Caribbean when he was overcome with an attack of vertigo that sent him to bed and required me and his wife to help him even across their bedroom to go to the toilet.  He was later diagnosed with Meniere’s syndrome, a disorder of the inner ear whose cause, in his case, was suspected to be viral, and which, in addition to the signature vertigo, often leads to partial or total hearing loss, usually in one ear, which is exactly what happened to Bob. I spent the next decade or so of our working life together repeating things to him and positioning ourselves at conference and dinner tables so that his one “good” ear was facing in the direction of people he needed to be able to understand. To this day he would be nearly deaf in one ear were it not for his high-tech hearing aid and other electronic prostheses, like the huge earphones he uses when watching TV.

So I was painfully aware and frightened of the phenomenon of sudden hearing loss, and knew it was nothing to mess around with. The only good news for me was that I had no vertigo at all. I got an appointment that very day with our internist, who peered into my left ear and saw exactly nothing unusual. I was given a simplified aural test with a hand-held tone emitter, and did fairly well – well enough that the doctor wanted to wait to resort to steroids, which I was surprised to learn are the gold standard of treatment for cases like this. I went home with instructions to call him over the weekend if anything changed.

Right on cue, things changed.  That night I lay awake in the dark of our bed, listening to what sounded very much like a jet engine in my left ear, a constant, rushing, high whine. Other random tones would come and go. When I held my right ear shut and snapped my fingers next to my left ear, I heard nothing.

Next morning I called the internist and was immediately put on prednisone, in a dose that would diminish over the course of a week. We also arranged an appointment two days later with an ear-nose-and-throat specialist.

The ENT visit entailed a thorough “audiological evaluation,” for which you sit in a dead-quiet metal closet with headphones on your ears and listen for a series of extremely soft, barely-detectable tones of varying frequencies and push a button if and when you hear one.  I abjectly failed this test in the left ear.  Hearing loss is graded on a spectrum in which “severe” is exceeded only by “profound,” meaning you are stone deaf.  Mine was “severe.”

My ENT specialist (an otolaryngologist, to be precise) was a tall black woman in her late thirties with a manner as precise, stern and all-business as you might expect a black, female M.D. in an advanced surgical specialty would have long ago learned to be. She said this “sudden sensorineural hearing loss,” or SSNHL, happens and we don’t know why, that my original sense of distressed cilia was exactly right, that the cause could be a virus, that the dosage of prednisone I was on was slightly wrong but she would correct it (it needed to taper off over a much longer period), and that the good news was that I’d come in early, as the effectiveness of the steroid is directly correlated with how soon after onset it is administered. In most cases where the treatment is begun promptly, some or most of the hearing loss resolves over time. She offered to administer the steroid by injection – that is, into the inner ear through the ear drum — but told me that there’s no good evidence that this works any better than the pills, so with her permission I gratefully declined the privilege of having my eardrum perforated with a needle. She prescribed an MRI to rule out possible but unlikely causes, such as stroke, a brain tumor, or tumors of the auditory nerve, which are apparently not uncommon but almost never malignant.

Somewhat reassured but still effectively deaf in one ear, I went home to wait. I read up on SSNHL, and realized that if my condition were permanent, I would have to become fiercely protective of my one working ear. Scuba would be out forever, loud music an anathema, the sirens of our small town’s fire engines an existential threat to my well-being.  And what if, God forbid, the same thing happened to the other ear (though I read in all the literature that, for some reason, this almost never happens)? I comforted myself with thoughts of great geniuses who had been deaf: Beethoven, Edison.  It’s a short list.

My mood was one not so much of fear as of great sadness bordering on depression, the way one might feel if a favorite pet who had been with you for your entire life might have to be put down. I was in anticipatory mourning for one of my senses, which might never again be as I’d known it.

As it was, the main impact of my malady was a complete loss of the “stereo” effect that is second nature to our sense of hearing.  I had no ability to detect where a sound was coming from.  A neighbor to across the street to my left would call out a hello and I would look instinctively to my right, where my good ear picked up the sound of his voice as it reflected off a wall. Driving became a much more tensely-focused endeavor, as I tried to screen out deceptive vectors of sounds.

Sight is frontal; we control its direction, its variations in its quality are obvious from moment to moment, and it is so plainly vulnerable that we dote upon it almost constantly. Even taste, though not as critical to a normal life as sight or hearing, still presents itself to our consciousness so sporadically and pointedly that our awareness of it is acute; we know when it’s “off” because the wine tastes funny, and we can usually guess why.

Hearing is one of those wallpaper senses, like touch, that operates so continuously and so subconsciously that we think about it almost not at all, and its acuity or lack thereof is usually beneath our notice. It’s just there, always, slowly degrading as we age, but so gradually that even when we find we can no longer understand what our spouse is saying over breakfast, we think it’s purely psychological on at least one of our parts.

The sudden failure of the body –the beloved vehicle of the mind– for no apparent reason, when we’ve done everything right or at least nothing wrong, is an unwelcome reminder that no machine lasts forever. Things fall apart; components fail. A disease you never heard of steals your hearing overnight. Minor injuries mutate into chronic disabilities. The guy who says he’s feeling great promptly keels over with a heart attack. We’re complex organic machines that grow old and fail; anything can happen. Yet the only story the body knows to tell its tenant is that this day will be like all the days before.  And we believe it.

I had the MRI and it was completely normal.  The steroid regimen ran its course, and by the end of it I thought I could hear a muffled click when I snapped my fingers beside my left ear.  The nighttime roar of the jet engine seemed to subside a bit. My wife and I spent a weekend in New York with my half-deaf friend Bob and his wife, who were more than conventionally sympathetic and with whom we laughed over how much more complicated our seating arrangements at dinners might become. Bob told me all about his latest hearing aid, which he can control for different aural environments with an app on his phone.  I was impressed but not covetous.

Since then, hearing in the damaged ear has returned ever so gradually but almost completely. It’s still not normal, as I can readily test by holding my cellphone to one ear and then the other in the midst of a conversation: certain tones and timbres – frequencies that were once the job of what must be crippled cilia – are still missing in the left ear, and in quiet moments the white noise of tinnitus is still there, like a long, unbroken note held forever on a moldy old piano.

But compared to the near-deafness of those first few days, this is a providential gift. I can live with this mostly-hearing, could live with it indefinitely, and may have to. I feel like an ungrateful child who has been taken aside and sternly reminded of how to behave in front of company; loss is what teaches us gratitude for what remains.