In the womb, a fetus may begin to hear at 18 weeks

Touch is the first sense a fetus develops in the womb

During gestation, our sense of touch begins to develop around 8 weeks, starting with the development of sensory receptors in the face and, about a month later, in the palms and soles of the feet.

Pediatricians look for a list of behaviors to signal typical hearing development

These markers of typical hearing development among infants and toddlers include turning head to sound sources within the first five months of life, babbling by about 11 months, and trying to imitate simple words by 17 months of age.

Babies taste food in the womb via amniotic fluid, and it may influence future taste buds.

Fetal development, week by week

Gestation is the period of time between conception and birth when a baby grows inside the mother's womb. Changes occur constantly over the course of these 40 weeks. At week 17, for instance, the skeleton of a fetus begins changing from soft...

What happens during the first eight weeks of pregnancy?

The first weeks of embryonic development, known as embryogenesis, are one of the most critical phases during pregnancy. This simple breakdown from the Khan Academy illustrates what we know about how the complex process unfolds.

Infants are particularly at-risk for ear infections

The Eustachian tubes, which connect the middle ear to the upper throat and help to drain fluids and equalize pressure, are relatively flat at birth, making it hard for gravity to assist with drainage. The angle of these tubes changes and becomes steeper as we age, making fluid buildup in the ear canal less common.

Newborns have a strong sense of smell

Babies are drawn to their mother's smell—and the particular odor of their mother's breast milk—within days, even as their vision remains blurry for months after birth. In the womb, the olfactory center also forms in the early stages of development.

The three smallest bones in the human body—the malleus, incus, and stapes—amplify the vibrations of sound waves by almost 20 times to help enable hearing.

Heightened sense of smell during pregnancy is not yet well understood

Boosted smell powers and strong reactions to them are often reported beginning around the six-week mark of pregnancy. Researchers say hormonal changes likely play a role, but the change remains poorly understood.

Exposing fetuses to certain flavors in the womb could lead to children being less picky eaters

A new study found that 3-year-olds were less averse to the smell of vegetables they had been repeatedly exposed to in utero, suggesting that what mothers eat in late pregnancy can leave a lasting imprint on their children's tastes.

Explore this week-by-week visualization of pregnancy

This graphic illustrates how development proceeds during each week of pregnancy, tracking what shifts and milestones typically occur during each stage of the process. It also includes typical weights of the fetus throughout.

Examine this captivating animation 'building' a human—illustrating the roughly 40 weeks of fetal development.

Neanderthals commonly had surfer's ear, a potential sign of extensive seafood collection

Analysis from 2019 found that about half of the 23 Neanderthal skulls scientists examined seemed to have the bony growths in the inner ear, signifying they had surfer's ear. Those growths suggest our ancient relatives, dating back to between perhaps 100,000 and 40,000 years ago, were potentially hunting fish, mollusks, or other marine resources in chilly waters.

Some animals possess sensitive hearing to help pinpoint prey and map the world

Bats and dolphins produce sound to reflect off surfaces and create a mental image of their surroundings. Owls' faces are dish-shaped to help funnel sounds to their ears, including that of mice moving along leaves or snow. Pinnipeds, such as seals and walruses, hear in both air and water.

Babies don't develop a circadian rhythm right away

Newborns don't develop circadian rhythm until they are a few months old, which helps to explain their erratic sleep schedules. When they're around three months old they begin to release melatonin, which influences sleep, and around the same time they develop more regular sleeping routines.

If hearing is damaged, the brain may amplify remaining sounds, perhaps causing tinnitus.

Embryonic stem cells can develop into any other cell type in the body

Embryonic stem cells emerge around five days after fertilization, during the blastocyst stage of embryonic development. At this point, the embryo consists of about 100 to 150 cells and forms a hollow structure, and these cells are the ultimate source of all other cell types during fetal development.

Surfer's ear, from repeated cold water exposure, leads to new bony protrusions in the ear

Frequent exposure to icy cold water, typical in surfing, can cause tiny bony growths to develop in the ear canal, informally called surfer's ear. While the exact cause for these growths is unknown, it may be the body's protective response to shield the ear drum from the cold. These protrusions can heighten the risk of swimmer's ear, lead to wax buildup, and result in hearing loss.

Cochlear implants stimulate nerves inside the ear to provide the sensation of sound

In a surgical procedure, one part of the implant is placed under the skin behind the ear and electrodes are threaded into the cochlea in the inner ear. Another part of the implant sits behind the ear and picks up sound and then converts it into patterns of nerve stimulation.

How the heart achieves its first beat

Scientists observed zebrafish embryos as they grew and isolated the several-second-long initial heartbeats to better understand this crucial moment in every heart's life. The zebrafish's heart starts beating 20 hours into their existence. Each heart cell activates electrically at random, without rhythm. As these cells mature, they become more sensitive to electrical charges; as they all fire, a rhythm is established and a pulse is born.

Gene therapy for a rare type of deafness is allowing deaf children and adults to hear for the first time, according to research results reported in April 2026.

One decibel of hearing loss increases tinnitus risk by 6% for older people

That's according to an analysis of more than 18,000 people published in BMC Medicine in 2023. The tinnitus risk is not just limited to older people: The research also concluded that one decibel of hearing loss increases the risk of developing tinnitus among young adults by 3 percent.

Children are at increased risk of contracting swimmer's ear

Kids may be more likely to spend time at the pool so they have that water exposure. They also tend to have narrow ear canals, a prime location for water to get trapped. Frequently wearing earbuds or excessively trying to rid ears of earwax, however, can also increase the chances of painful swimmer's ear infections at any age.

A pregnant woman's brain sheds gray matter, perhaps explaining 'baby brain.'

Tornadoes produce inaudible signals to humans hours before forming

Researchers at the National Oceanic and Atmospheric Administration have found that tornado-producing storms generate specific sounds below the range of human hearing, much like the infrasonic signals produced by earthquakes and avalanches. Although difficult to distinguish from wind noise, scientists hope to build systems that use these signals to improve tornado forecasting.

Some animals may speak because of duplicated connections in the brain

Neuroscience suggests that connections responsible for motion made during embryonic brain development—such as those connecting hearing and movement pathways that allow reactive motion when started—are duplicated and connected to the larynx in some animals. This allows some mammals and song-learning birds to speak, provided they have the necessary physiological structures.

Some men may be at elevated risk of inheriting tinnitus

A 2017 Swedish Twin Registry study suggests that bilateral tinnitus—when tinnitus occurs in both ears instead of just one—appears to be heritable, at least in men.

Explore how the placenta acts as lungs, kidneys, and more in the womb.

The science and ethics of artificial wombs

Artificial wombs may be able to help preterm babies survive their early entry into the world and possibly curb the long-term adverse health effects associated with such premature birth. This article dives into the current ethics and science behind artificial wombs and ectogenesis, which is when a fetus develops in artificial conditions.

Most custom earmolds for in-ear hearing aids are made using 3D printing

The technology has also been utilized for behind-the-ear and receiver-in-canal hearing aids, allowing for the creation of structures tailored to the patient's anatomy for enhanced effectiveness. 3D printing has also been used to print retinal eye cells and custom eyeglass frames.

See this graphic describing what different decibel levels mean for hearing loss.

See what loud noises do to inner ear hair cells

This animation illustrates how louder music can affect inner ear hair cells. Damage to these cells is generally considered permanent. Hearing protection like ear plugs can reduce the level of sound entering into the ear and help protect those cells.

More than 90% of American deaf children are born to hearing parents

The National Institute on Deafness and Other Communication Disorders have collated top statistics about hearing loss in the US including differences by age, racial groups, and other factors.

See why wearing earbuds—instead of over-the-ear headphones—can cause ear infections

Earbud headphones can heighten the risk of ear infections. They can lead to earwax buildup and create a dark, moist environment as you sweat—ideal conditions for germs to thrive. Wearing external over-the-ear headphones or ones that don't enter deep into the ear canal can help.

Listen to the earliest known recording of a whale song

A recording of a humpback whale was taken by scientists from the Woods Hole Oceanographic Institution near Bermuda in 1949, but forgotten for decades. When first captured, researchers didn't know what animal they were hearing, and therefore didn't catalogue the recording. The well-preserved audio was found by the team's archivist in 2025.

Understand the complex, biological journey of pregnancy with this science explainer.

Ultrasound machines emit and receive high-frequency sound waves to construct images of the body's interior, with differences in the penetrating power of different frequencies allowing medical professionals to identify different structures.

Explore why swimmer's ear will not go away on its own

This infection is typically treated with ear drops to reduce inflammation and fight the bacteria or fungus that led to the issue. But without treatment, complications can arise, including a deep tissue infection, bone or cartilage damage, or—very rarely—spreading beyond the ear into the skull bones and surrounding areas.

Doctors explain that most ear infections—but not swimmer's ear—affect the middle ear

A typical ear infection occurs in the area behind the eardrum, but swimmer's ear is an infection of the ear canal. Its characteristic symptom is pain whenever the ear is moved, though it can also include itching and a sense of fullness. Symptoms typically begin within a few days or a week of a water buildup not being addressed.

Each day, about 60 US pregnancies end in stillbirth

This online memorial for families who experienced the unexpected death of a fetus 20 weeks or older is the result of ProPublica reporters inviting 60 families to share their baby's name and answer some questions about their unfulfilled wishes for their children. About 21,000 babies are stillborn in the US annually. About the same number of children die in the US during their first year of life.

Gene therapy is restoring hearing among kids with genetic deafness

Gene therapy for profound genetic deafness has been advancing in recent years, with multiple clinical trials enabling hearing at normal levels for the first time without hearing aids or cochlear implants. The therapies target hearing loss caused by mutations in the OTOF gene that codes for a protein called otoferlin. That protein normally plays a key role in relaying sound signals in synaptic transmission between the ear's inner hair cells and the auditory nerve.

Ancient Egyptian papyrus from 16th century BCE seems to reference tinnitus

Ancient Egyptians wrote that they treated "bewitched ear" with herbal concoctions that involved frankincense and other ingredients, which were placed in the ear.

‘Hope for Healing’: The first-ever use of an in utero stem cell treatment

In 2023, researchers at UC Davis performed the first-ever fetal stem cell transplant, attempting to cure a case of spinal bifida prior to childbirth using stem cells derived from the placenta. The trial, and others including an effort to treat muscular dystrophy, highlight the potential power of stem cell therapy.

Steps for buying your first hearing aids

Hearing aids have advanced in aesthetics, simplicity, and cost in recent years, but acquiring them can be daunting for first-timers. Experts suggest finding a high-quality audiologist and knowing your rights with medical services. They also recommend buying them sooner rather than later, as hearing issues can compound and grow more costly over time.

Tinnitus estimates vary, but may occur in 10%-15% of the population

This video discusses the mechanisms underlying tinnitus and explores the knowns and unknowns about the condition. Tinnitus most commonly occurs among those with hearing loss, suggesting that cochlear damage may be a factor.

Notch music therapy may filter out some tinnitus frequencies

Researchers in Germany have developed a smartphone app-based therapy for individuals with tinnitus associated with hearing loss. Some people with tinnitus can use this Notch app with their hearing aids to at least partially block sound frequencies matching their tinnitus pitch—turning down the volume of their tinnitus.

Pregnancy at older ages increases the chances of fetal abnormalities

Chromosomal irregularities are more likely at older maternal ages so genetic testing for a fetus of mothers-to-be at age 35 and older is often recommended. Conditions that can be screened for in utero include cystic fibrosis, Tay-Sachs disease, sickle cell disease, Down syndrome, spina bifida, Duchenne muscular dystrophy, and more.

People with tinnitus should avoid silence—sound-rich environments distract the brain

This podcast from an audiologist discusses common questions about tinnitus. It notes that tinnitus could be described as a phantom sound associated with hyperactivity in the brain. It's linked with loud sound exposures above 85 decibels, hearing loss associated with aging and stress, among other factors.

How hearing protection became cool

In recent years, the WHO shared research findings that over 1 billion teens and young people face risks of hearing loss due to unsafe listening practices. While earplugs used to hold a reputation for being uncool, this article explores how awareness has led to more people fashioning different types of hearing protection. Explore the growing trend of earplugs at raves, concerts, and other loud events.

Using artificial wombs to improve preterm infant health outcomes

Researchers at a hospital in the US have successfully used artificial wombs to care for preterm lambs and are now looking at the possibility of human trials. This nine-minute video includes interviews with the researchers and explains the reasoning...