Why autism gave me supersonic hearing

And what that reveals about how our brains predict, filter, and endure the world

When I watch TV, subtitles are on—always. When I go out to dinner, I never catch the specials. At parties, bars, anywhere with a buzzing crowd, about half the time I’m only pretending to hear what’s been said.

And yet, I can hear the pitter patter of tiny feet on a staircase two rooms away. Despite earplugs, my husband’s loud breathing keeps me from falling asleep. And once I do, the soft creak of a window shifting in its frame is enough to wake me again.

If these things seem utterly contradictory to you, you’re not alone. For years, I’ve been flummoxed: how could I be so hard of hearing in some situations, and supersonic in others?

It turns out, there’s nothing wrong with my hearing itself—my ears are garden-variety.¹ The issue lies in auditory processing, or how my brain processes sound.

I put this together after reading a lengthy research review² on a different subject: the predictive skills of people with autism.

Many things are tied up with our ability to make predictions, but of particular importance here is habituation. In one study, habituation was defined as “the attenuation of neural or behavioral response over repetitions of the same stimulus,” which is really just referring to the point at which the brain says: I’ve seen (or heard or felt) this before—I don’t need to react so strongly now.

The more predictable something is, the more the brain tends to habituate (calm down, stop reacting). A habituation response is a signal that the brain has successfully made a prediction and decided it no longer needs to keep reacting. Without that prediction, the brain is alerted whenever the sensory input occurs. The more a person struggles with prediction, the less pronounced their habituation responses will be.

To see habituation at work, imagine someone moves into an apartment above a busy intersection. At first, they might jolt awake at every honk or siren. But after a few weeks, they sleep through it. Their brain has become accustomed to the noise—the sounds are predicted—and no longer reacts with the same intensity. Habituation is the brain’s natural “tuning out” process.

In autism, due to challenges with certain kinds of predictions, habituation happens more slowly. The world stays loud, bright, and distracting even when it’s familiar.

This explains my ping-ponging hearing, in which I struggle to hear what people are saying in some situations, and hear such teensy noises at other times that I lose sleep.

(Not all predictive capabilities are impaired in autism. A specific domain is affected: contextual modulation, which causes challenges with integrating or relying on environmental signals when making predictions.)³

Those times I’m straining to hear what’s being said, it’s because there’s a lot of background noise. That happens to everyone, you might say. True, but my problem is that I’m uniquely unable to hear in these situations. Everyone else follows the conversation just fine, as the background noise fades into irrelevance. But for me, every sound remains equally loud, equally important. Nothing gets filtered out.

They can hear what’s said because they’ve become habituated to the din around us. Their brains zero in on the useful sounds: the voices in the immediate conversation. My brain hasn’t habituated—it hasn’t turned down the volume on the background noise—and as a result I can’t distinguish what the person next to me is saying from the clatter of dishes or the music floating through the sound system.

Even though at night my hearing is seemingly too good, it’s the same mechanism at work. When it’s time to sleep, most people’s brains habituate to the nighttime soundscape. Their brains tell them the neighbor’s barking dog or the AC turning on is nothing important. My brain, on the other hand, reacts to each noise anew: Hear that? And that? Oh there it is again!

(Not really, of course; there’s no internal chatter about these sounds. This isn’t something I can will away. Habituation happens below the level of conscious awareness. If I could choose which sounds to ignore, I would have done it long ago.)

That’s the irony: what looks like contradictory hearing—partially deaf in one context, hypersensitive in another—is really the same mechanism at work. A brain that doesn’t know when to stop paying attention.

This habituation slowdown likely also explains why some autistic people experience sensory overload. The slower the brain is to habituate, the louder, brighter, itchier, smellier, and altogether more overwhelming the world becomes. What is tolerable or even pleasant to someone whose brain habituates easily may be utterly intolerable to a person with autism.

My sensory sensitivity, for all my trouble conversing and sleeping, isn’t particularly severe. It doesn’t stop me from going to concerts, or attending sporting events (my lifelong disinterest in sports stops me from that). But understanding how my lack of habituation does result in a sonar experience that’s completely out of sync with others has given me more empathy for the extreme range of autistic experience.

If you’re neurotypical, understanding how habituation works might help you empathize, too. Imagine a time when something was just too much for you—too loud, too bright, an overpowering stench, a feeling that made your skin crawl. That’s how it feels for some people constantly, as the initial punch of a strong perfume never fades, or the idle bleating of a car alarm demands all their attention. The sensation might feel within the range of normal to you, but that’s because your brain has calibrated it. For them, it’s dialed all the way up.

It can get bad. In one study,⁴ researchers compared the autistic sensory overload—rooted in a chronic inability to make predictions from sensory input—to torture:

Several studies have demonstrated that unpredictability of stressors is one of the key aspects of torture and leads to the development of anxiety, fear, and aversion. “Acoustic bombardment” has long been used as an instrument of torture. Unfamiliar, and hence unpredictable, music is found to be especially effective. Tying this back to the domain of autism, the PIA hypothesis suggests that an endogenous predictive impairment causes environmental stimuli to appear more chaotic, leading to reduced habituation and hence greater stress.

All this urges attention to autistic children in particular. Children lack control over their environments and can’t easily flee when sensations become too much. Although it’s hard to understand a sensory meltdown if the environment seems just fine to you, appreciating that their experience is truly different—and that they’re powerless to stop the sensations flooding in—can lead to more patience. Their suffering is real, even if you can’t experience the cause.

And thus ends the story of how I finally figured out why my hearing is whacky. Thanks for listening.

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Did you like this deep dive into neurodivergence research? If so, support my work by putting a small amount in my tip jar. That’ll allow me to keep publishing without a paywall. Thank you!

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To branch out from here, you might read:

• Jyoti Madhusoodanan’s article for The Transmitter, Confusion at the crossroads of autism and hearing loss

• Nick Dean at Neurokindness’s piece “Sensory overload. Heathrow. I should have thought this through”…

• Jack Eaton at Asterisk Mag on misophonia in The Unbearable Loudness of Chewing

• Ebony Nash from Meticulously Organized Chaos on Reasons I thought I may be autistic: Sensory Edition

1. Because I’m me, while writing I looked up the origin of the term “garden-variety,” as used to refer to the utterly mundane. The term has its roots in horticulture (figures). A “garden-variety” plant is one that is commonplace, unexceptional: the kind you might have in your garden. As distinguished from a rare, exotic, or specially bred plant or cultivar.

2. Cannon, J., O'Brien, A.M., Bungert, L., & Sinha, P. (2021). Prediction in Autism Spectrum Disorder: A Systematic Review of Empirical Evidence. Autism Research, 14(4), 604–630. https://doi.org/10.1002/aur.2482

3. As mentioned, this isn’t about a blanket inability to make predictions. Autistic people are often excellent at forming certain types of predictions, particularly those rooted in consistent, rule-based systems. What’s different is the way the brain adjusts or updates predictions in dynamic, noisy, or uncertain environments. The issue lies in what’s called contextual modulation: neurotypical brains tend to “tune” their predictions based on how reliable a situation is likely to be. In autism, this tuning mechanism works differently. As a result, the brain may not “learn” that a repeated stimulus is safe to ignore, which slows habituation. Instead of calming down in response to familiar sounds or sensations, the brain keeps flagging them as important. This can lead to hypersensitivity, not because the senses are stronger, but because the brain hasn’t filtered out irrelevant inputs.

For more, see Bianco, V., Finisguerra, A., Betti, S., D'Argenio, G., & Urgesi, C. (2020). Autistic traits differently account for context-based predictions of physical and social events. Brain Sciences, 10(7), 418. https://doi.org/10.3390/brainsci10070418

4. Sinha, P., Kjelgaard, M.M., Gandhi, T.K., Tsourides, K., Cardinaux, A.L., Pantazis, D., Diamond, S.P., & Held, R.M. (2014). Autism as a disorder of prediction. Proceedings of the National Academy of Sciences, 111(42), 15220–15225. https://doi.org/10.1073/pnas.1416797111