We set out to validate our hearing screener, which uses a spatial-hearing paradigm to detect hearing loss. We didn’t expect young adults to have any trouble with the test. After all, most research suggests they should perform well—if not better than older adults—on tasks involving binaural processing.
But that’s not what we found.
In our pilot study, we tested 30 individuals under 30 and 56 individuals over 30 using the Hearing Diagnostics Screener (HD-S). The test is simple: participants listen to simulated spatial sounds through headphones and turn towards them to localise them, relying on their binaural processing—the ability to use sound cues from both ears to determine where a sound is coming from.
The results were completely unexpected:
- 95% of adults over 50 with normal hearing localised the sounds without any issues.
- Only 60% of adults under 30 with normal hearing were able to localise the sounds.
At first, I was convinced something had gone wrong. I’ve spent years researching central auditory processing and spatial hearing, and this went against everything I’d seen before. But as we continued testing, the trend remained.
It wasn’t until we started chatting with the younger participants that a possible explanation emerged. Many told us they struggled to hear in noisy environments. When we asked about their listening habits, a pattern became clear: most were using headphones for hours every day—for university, gaming, socialising, you name it. Some had been wearing them all day, every day, since high school—years of near-constant headphone use.
It’s Not About Noise Cancellation Alone—It’s About Headphone Exposure
A common reaction to our findings is to assume that noise-cancelling headphones might be the issue. But I don’t think that’s the case. The concern isn’t noise cancellation itself—it’s the nature of headphone listening overall.
Headphones, by design, deliver non-spatial sound. Music, podcasts, and most digital audio don’t replicate how sound behaves in the real world. When listening through speakers, sound interacts with the environment, creating natural cues that help us determine direction and depth. But headphones strip away those spatial cues, feeding sound directly into the ears without real-world relevance.
If young people are growing up primarily listening through headphones, are they missing critical exposure needed to develop spatial hearing properly?
Could Headphones Be Affecting Auditory Development?
Binaural processing and spatial hearing aren’t just inbuilt skills—they develop over time. As we grow, our auditory system adapts to the world around us, learning how to interpret the complex cues that tell us where sounds are coming from. Even in adulthood, the brain remains flexible.
A fascinating study by Marc Schönwiesner’s lab in Montreal demonstrates this adaptability. Participants were given custom-made earmoulds that altered the way they perceived sound direction. At first, they struggled to localise sounds properly. But after wearing the moulds while going about their daily lives, their brains adjusted—they learned to process the new cues and could localise sounds accurately again. Even after the moulds were removed, their adapted spatial hearing profile lingered before gradually returning to normal.
Now, imagine a similar scenario, but instead of temporary earmoulds, young people are constantly listening through headphones—which don’t offer real-world spatial cues. Could this be preventing their auditory system from fully developing its binaural processing abilities?
Our Screener: A Step Towards More Comprehensive Hearing Health Testing
An exciting thing we’ve learned from this study is that our screener seems to be testing for two important components of hearing health:
- Hearing thresholds (what is the quietest sound you can hear?).
- Central auditory processing (how your brain processes and interprets sounds, including localisation).
This opens up the potential for a screener that not only assesses hearing loss, but also provides a more complete picture of a person’s real-world listening abilities. If we can better understand how individuals process sound in space, we can give them more accurate, actionable information about their hearing health.
We’re still at the beginning of this journey, but the possibilities are promising.
What Does This Mean for the Future?
Our findings raise big questions about how modern listening habits are shaping auditory development. This isn’t just about hearing loss or noise exposure—it’s about the way we process sound in space. If young adults are struggling with spatial hearing now, what might this mean in the long run?
We don’t have all the answers yet, and this needs further investigation. If you work in auditory neuroscience, audiology, or related fields, we’d love to hear your thoughts. Let’s figure this out together.
Since publishing this article, we have followed up our findings with a brief, informal questionnaire focused on headphone-listening habits among our younger participants (under 25 years of age). While not a scientifically validated instrument due to the small sample size and lack of proper controls, it provided a preliminary insight into the patterns we were seeing. The responses strongly supported our hypothesis that near-constant headphone use affects listening performance in young adults. Most strikingly, one-sided listening (i.e. using a single earbud or AirPod) emerged as a particularly significant factor, even in individuals with symmetrical audiograms. Exposure to active noise cancellation, by contrast, only moderately accounted for the results.