Introduction: Hearing in a Different Light
Hearing is one of the most used of our faculties and one of the secret unknowns of the biology of humans. We’ve known we lose our hearing as we get older and that loud sounds—those of city streets or ear-rupturing concerts—grate away at eardrums. But a study published on March 28, 2025, in *Scientific Reports* revealed a secret in plain sight: sex. Women, it turned out, had significantly better hearing than men, enjoying a steady two-decibel lead across population groups globally. And importantly, it dwarfed the impact of age as the single biggest indicator of hearing amplitude, reversing decades of assumption in terms of dwindling hearing.
Led by France’s Centre for Biodiversity and Environmental Research’s Patricia Balaresque and in collaborative effort with the UK’s University of Bath’s Professor Turi King, the international study investigated the intricate interaction between environment and biology in hearing. Screening 450 people in 13 populations across the world, ranging from countries in Ecuador, England, and Gabon to South African and Uzbekistan, the scientists were able to paint a detailed picture of hearing variability that was both reflective of evolutionary origin and modern environment. Detailing their study in full, the article dissects implications for health, science, and current knowledge of adaptation in humans.
The Science of Sound: how the study was conducted
In measuring hearing sensitivity, researchers looked to the cochlea, that spiral device deep in the inside of the ear that collects sound vibrations and transfers them in the form of electrical signals to the brain. They were taking a measure of Transient-Evoked Otoacoustic Emissions, or TEOAE, which is a measure that listens in on how the cochlea responds to a sequence of varying sound frequency and intensity. It’s nothing more than an echo: as sound comes in, the cochlea emits a very soft emission that can be detected and quantified. It enabled researchers to measure not only how loudly people can perceive sounds, but how well-tuned their hearing system is to a wide range of pitches.
The groups were chosen in a strategic sample of societies diverse in type, drawn to include wide ranges of culture and ecology. From Gabon’s rainforests to Uzbekistan’s mountains, and English and Ecuadorian towns in the rural environment to English towns, the groups offered the rare opportunity of comparing hearing in relation to Western nations’ usual preoccupation. To view the world as a single unit, and not to view Western societies compared to Western societies, is a new approach in the study of audition, one that, until now, had relied extensively in most cases on European or North American samples to which non-Western and rural societies had remained under-researched.
The Big Reveal: Sex Steals the Day
The results were unexpected. Women had two decibels better hearing acuity on average than men in 13 groups of humans—a disparity that persisted across geography, language, and lifestyle. And although two decibels may not sound like much (a range of roughly that between whispering and hushed conversation), it was a significant statistical disparity that implies a simple biological one. And one that outranked one other cause of hearing amplitude variability: age.
Professor King, sampling in the UK for the University of Leicester, was taken aback by the discovery. “We were amazed that we were able to find that the women had two decibels’ better hearing in all of the groups that we were sampling, and that explained almost all of the individual variability,” she explained. For perspective, we find that as you get older, hearing gets worse—hair cells in the cochlea get damaged, neural impulses get slowed—and that the right ear hears better than the left ear due to asymmetry in the brain. But we weren’t anticipating dominance by sex, so the researchers probed further for other explanations.
Why would women’s hearing be better? One hypothesis centers on hormones. Female and male versions of estrogen and testosterone are structurally very different, and the cochlea may be influenced by this in utero, perhaps changing in structure or sensitivity in some subtle fashion. And it may be anatomical: men and women may be subtly different in cochlea size, or cochlea shape or cell structure, though differences of this type are somewhat of a mystery. And in addition to simple sensitivity, women also score better on speech perception tests, which means their auditory processing—performed by the brain—may be better. As Professor King explained, “Women also perform better in other hearing tasks and in speech perception, which means their brains are also better at interpreting the information.”
Role of the Environment: Forests, Altitude, and Noise
Sound was the remaining variable, though—environment was a close second in range and scope of sound heard by man. Forest dwellers, for example, in Gabon, had the most acute sense of hearing. Perhaps it is an evolutionary adaptation to a bird call, leaf rustling, and ambient-noise environment where acute hearing may be a survival adaptation to tune in to predator or prey. Perhaps it’s simply a lower exposure to modern toxins of the kind like traffic exhaust or factory din that degrade auditory processes over the lifetime of a person.
Compare them to humans living in high altitude, e.g., residents of Uzbekistan, lowest sensitivity. There may be many reasons: thinner air in high altitude may mute sound transmission, less oxygen may affect biology of the ear, or air pressure may distort readings of TEOAE. We remain in the unknown as to what the mechanism is, although the trend is consistent across the board. City folk—consider Londoners in their day-to-day hustle and bustle—had a trend toward hearing higher frequencies, perhaps in order to drown out the rumble of cars and machinery that is life in cities. Rural residents had greater sensitivity across the board.
Such differences in environments are transient responses to modern day conditions or are real evolutionary adaptations that have built up over hundreds of generations? We were unable to settle this argument in this study, but we point in the direction of how thoroughly environments condition how we see the world.
Beyond Biology: Culture, Language, and Pollution
They also learned that population, language, and immediate environment were all significant in the perception of variation, although these strands were hard to separate. Language, for instance, may affect the way we perceive—tonal language speakers like people in certain African or Asian nations may tune in differently to non-tonal language speakers like English speakers, for instance. Cultural custom may also be operating: a fieldworker in a remote corner of Ecuador may employ acute hearing in everyday life in a different way to a Johannesburg city resident.
Pollution remained a wild card. Cigarette smoke and city sounds, and chemical pollutants, all damage hearing, and the study’s urban/rural division confirms it. Forests, which also tend to keep air fresh and the planet quieter, may save hearing, while cities erode it. High-altitude environments, where the unique atmospheric complications there exist, provide yet one additional confounding factor. As Dr. Balaresque explained, “Assigning causes of natural hearing variability will inform knowledge of hearing loss and variations in susceptibility to noise among people.”
The Double-Edged Sword of Sensitive Hearing
Improved hearing in women is a superpower that sounds desirable, though it comes with a catch. In noisy settings-noisy pubs, construction sites, or sleepless nights near highways-increased sensitivities mean increased stress, disrupted sleep, or even increased cardiovascular risk as increasingly, pollution through sound is tied to heart disease. “With the detrimental effect of sound on overall health,” Professor King mused, “there may never be benefit in having greater hearing in noisy environments.” It is one of life’s contradictions: what is a strength in one sense is a vulnerability in another.
Implications and Future Research Directions With hearing loss continuing to rise globally—driven by aging, city life, and earbuds galore—this study offers a new perspective on prevention and cure. With environment and sex also becoming determiners in the equation, audiologists would then be able to tailor treatments increasingly precisely, either in the form of tailor-made hearing aids or sound-reduction strategies in the environment. It also makes one-size-fits-all treatment of hearing suspect and compels researchers to look beyond the extremes of both aging and sound exposure. The outcomes also raise broader questions of evolution. “We know that we are evolving,” said Professor King. “So the question then is: Can we tune hearing in accordance with the environment overall, or is there a genetic adaptation occurring?” Is the acute hearing of the wood dwellers the product of natural selection over centuries, or is it a transient adaptation to the environment? Is the urban dwellers’ love of high frequencies a heritable condition? Those are questions to be sorted out in the years ahead by the scientific community. Conclusion: A Symphony of Difference This study, publishing in *Scientific Reports* as “Sex and environment shape cochlear sensitivity in human populations worldwide” (DOI: 10.1038/s41598-025-92763-6), is a wake-up call to rethink the nature of hearing. It has nothing to do with twiddling it later or growing old—it’s one of whom we are and where we come from and how we’ve learned to tune in to the din of the world. For women, it is a quietly triumphant victory of biology; for science, it is a wake-up call that in all of its variations, we are defined by what we are yet to listen for.
