So Neuroscientists Have Found a Way to Stop It, But What Exactly Is Tinnitus?
Silencing the dull screech of hardcore shows gone by.
Image: Pig Destroyer/Josh Sisk/used with permission
At my music critic peak, I was going to probably five or six shows in any given seven days, and probably more than that taking into account nights where it might be possible to drop in on two or three in a single go, or maybe even more if you include wasted afterparty DJs in suddenly rather bleak warehouse spaces. This seemed about as reasonable then as my current evening equivilent of reading textbooks about data structures and microarchitecture, or parsing papers about single-dimensional Bose gases and mystery photons in the intergalactic medium. One nice thing about the latter pastime is that I don't tend to wake up the next morning enveloped by the piercing high whine of tinnitus.
I say "high whine" because that's how it manifested for me, though the condition can take many forms, including phantom buzzing, ringing, whistling, hissing, humming, or whooshing. The basic idea of tinnitus is that it's some sound not present in the real world that invades your ears and won't go away, usually the result of some sort of ear damage caused by being around loud noises or of age-related hearing declines. In rare cases, it might have a distinct physical cause (as in, it's a real sound), typically high blood pressure, but mostly not so much. It's just there and, while talk therapy can be helpful, tinnitus is moreso just a thing that sufferers have to deal with until it goes away on its own—or doesn't.
In more severe cases, tinnitus can even be rather devastating, leading to chronic insomnia, stress, anxiety, memory problems, and depression. When a more drastic intervention is called for, doctors may prescribe devices or hearing aids that produce white noise specifically calibrated to mask the tinnitus ringing. Even more advanced devices might adapt to an individual's own tinnitus, creating a pitch that not just masks the sound but retrains the ear to ignore it. In still even more severe cases, doctors might prescribe antidepressants or antianxiety meds like Xanax.
A new treatment currently undergoing testing in the US, marketed as the "Serenity System," however, gets to the very root of the condition in a new way, literally plugging into the vagus nerve, the big one connecting the brain to the body's myriad organs, and releasing pulses that help the auditory cortex of the brain "retune" itself in such a way as to eliminate the bothersome sounds. (Hat tips: New Scientist, FACT.)
The proposed treatment exploits what's known as "neuroplasticity," or the brain's (marvelous) ability to remake parts of itself in response to changing conditions or behavior. In concert with plasticity-fostering stimulation, patients are subject to brief bursts of noise, degrading the "frequency tuning of auditory cortex neurons," according to a 2010 Nature paper that found significant success with the technique in rats. "Repeatedly pairing tones with brief pulses of vagus nerve stimulation completely eliminated the physiological and behavioural correlates of tinnitus in noise-exposed rats," the paper reported. "These improvements persisted for weeks after the end of therapy." The current round of trials hopes to replicate this in human subjects.
Perhaps the most popular theory of common tinnitus, e.g. the sort that might result from being blasted with dangerous sound levels, is that damage to the tiny hairs lining the inner-ear's cochlea produces long-lasting auditory effects. That is, when your cochlea is blasted with noise, those hairs get bent or flatten, affecting the electrical signals transmitted to the brain's auditory cortex by the inner-ear. With skewed signals, a tinnitus sufferer experiences a skewed perception of sound—up to and including hyper-annoying, persistent sounds that aren't there.
Those cochlear hairs might in time correct themselves, but it might also not make much difference. The brain by then may have already reorganized itself in the image of that sound. The illusion then has become a "phantom phenomenon," in the words of a 1998 study finding high degrees of reorganization in the auditory cortices of tinnitus sufferers. The paper found that amounts of neural reorganization increased in tandem with the reported degree of the phenomenon. These neural changes are similar to those seen in amputees reporting phantom-limb pain; that is, phantom limbs are likewise tied to physical reorganization within the brain resulting from apparent increases in plasticity within the brains sensory cortex.
I suppose I got lucky with tinnitus and the whole standing-in-front-of-an-amp lifestyle generally (to say little of a full-on ruptured eardrum incurred in a highly ungraceful diving board accident), though I know at least a few of my peers in the music writing/music making worlds haven't been so lucky. Take heart, middle-age metalhead, science hasn't forgotten about you or the phantom tones that keep you awake at night.