Today is the first day in many, many weeks that I won’t put any medicine in my left ear, and the first time in the last couple of years that I’m not doing so because all is presumably as it should be in the ear. The hearing is not what it was prior to the surgeries, there’s probably a little further correction that needs to be done in the TMJ on that side, and I still need to keep the ear dry for now (that no longer being necessary will be an enormous milestone), but I’m getting a little more comfortable thinking of myself as healed. All through this, I’ve been meaning to go back and describe some of what I’ve learned about how the process of hearing actually works. I figured it would be a nice change from the fretting and complaining that has so far been the bulk of what I’ve had to say about this experience, but I’ve been hesitant to do so, mostly out of a sense of superstition. Telling the story of my ear surgeries and the subsequent healing process before that healing was done felt a bit like writing an autobiography while still in my twenties–it seemed the sort of hubris that invites catastrophe. But now I’m willing to take a chance.
When I came home from the first surgery, the ear packed with antibiotic jelly and my head wrapped in gauze, I had no external hearing in my left ear (though I could hear a wet squishing in the ear itself whenever anything on that side of my head moved). At first, my brain, receiving external aural stimulus only from the right ear, located the sources of all sounds directly to my right. In its experience to that point, the only time that it would receive aural stimulus associated with a specific sound that much stronger from the right ear than the left ear would be when the source of that sound would be straight to off to my right, in much the same way that most people’s brains would interpret the sound from a stereo with the balance turned all the way to the right. That evening, I was sitting in front of my computer, and my wife passed behind me from my right to my left, touching me on the way past. She was standing ten or fifteen feet to my left, and I could just see her out of the corner of my left eye. She called out to me, and despite all of the information I had telling me she was to my left, I heard the sound as coming from my right and I reflexively turned my head that way.
Thankfully, that only lasted a couple of days. Somehow, whatever apparatus in my brain interprets sounds realized that it was receiving input from only one side and adjusted accordingly. This meant that I was now hearing sounds as though they were coming from a single monaural speaker rather than from a right-sided stereo speaker. Though this was a less distorted interpretation of my experience, I was no longer able to locate the sources of sounds based solely on my sense of hearing. If, while walking in the street, I heard a horn blown or a person yell, I would turn around and around trying to figure out where the sound came from. I would do the same in the elevator lobby of my office when the bell announcing the arrival of one of the elevators rang, spinning around until I could find the light signaling up or down for the elevator that had just arrived. This had further unexpected implications, especially in the office.
What we understand to be a collection of separate sounds are together contributing to a complex pattern of vibration of our eardrums. Our brain uses several mechanisms to reverse the process of aggregation that happens as these diverse vibrations in the air enter our ear canal, and to allow us to experience simultaneous sounds as distinct. I imagine that the calculation behind this process is staggering, but it seems to happen instantaneously and seamlessly. It feels effortless to sit in the middle of a room with our eyes closed and independently identify and locate the sounds of the air conditioner to our right, the television in front of us, and the person speaking to our left. However, with one ear, all of those sounds seem to be coming from the same place. We can separate them to the extent that the sounds are qualitatively different, but if they’re of similar frequency and timbre, they’re virtually impossible to separate. With our eyes open, it gets easier because we can connect visual cues to parts of the noise surrounding us and make intelligible sounds of those parts (by, say, reading lips). So for weeks after the first surgery, if I was in a meeting and more than one person was speaking, it was almost impossible to understand any of what was being said. And ambient noises outside or in crowded places had the same effect.
The effects on my ability to properly interpret my experience were mitigated as the hearing in my left ear gradually returned. After the second surgery, I returned directly to the monaural state, without going through the interim broken stereo state. Whatever had made the adjustment after the first surgery remembered it and made it again immediately after the second surgery. I’d be curious to see brain scans showing if and how the physical structure of my brain and the patterns of my neurological activity changed as these adjustments were made and then gradually became unnecessary. And the fact that it all happened outside of my conscious awareness makes it seem less like a subjective process in which I participated and more like an objective process to which I was subjected. The change from hearing everything to my right to hearing without direction wasn’t a change about which I had any choice, but it also wasn’t genetic. It was an adaptive and, in some abstract sense at least, reasoned response by a mechanism that would have to be considered part of me, but over which I have no conscious control. This disruption of the normally invisible process of interpretation that mediates all of our experience made that process, or at least its effects, temporarily apparent, and highlighted how far from bare awareness and how thoroughly conceptual conventional conscious experience actually is.