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

A cochlear implant stimulates parts of the cochlea directly, with limited pitch and timbre capabilities

People with these devices have to learn or relearn how to train their brains to interpret nerve signals as sound. The range of the type of sounds that the brain can distinguish with a cochlear implant is limited and consequently it's difficult to understand a tonal language or distinguish individual speakers in a crowd.

The first neural devices were cochlear implants, designed to treat hearing loss

Neural interfaces connect with our nervous system to restore or enhance abilities, such as hearing or movement. These neuroprostheses have enabled the restoration of mobility, communication, and activities of daily living that might otherwise require a caregiver.

Cochlear implants are raising questions about deaf identity and culture

The rise of cochlear implants, which are usually covered by insurance and can enable hearing for many patients, raises questions about what it means to be deaf, the effects on deaf individuals learning American Sign Language, and about deaf culture. Watch this video that discusses the controversies and spotlights a little girl who hears for the first time with her cochlear implant.

736,900 cochlear implants had been implanted by 2020 worldwide

In the United States, roughly 118,100 devices had been implanted in adults by that point and 65,000 in children. These estimated figures come from the US Food and Drug Administration, which first approved cochlear implants for adults experiencing hearing loss in the mid-1980s, and collected reports from cochlear implant manufacturers approved for the US market.

Mind-controlled bionic arms use nerve implants to restore sensation and movement

Unlike traditional prosthetics that rely on surface electrodes or mechanical parts, this system uses implanted titanium and nerve-connected electrodes to enable a seamless brain-to-arm connection. Patients train in virtual reality with their implanted signals before using the physical prosthesis.

Brain implants can help colorblind people hear colors

Colorblind artist Neil Harbisson was born into a world of grey. In 2004, he had a chip installed connected to an external color frequency sensor. Once the sensor "reads" a color, it sends a signal to the chip and plays an associated sound both in and outside Harbisson's head.

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

Recent mouse brain and ear imaging revealed that the creature compensates for hearing loss by sending signals to the cochlea in the inner ear. This triggers nerve fibers in the inner ear to increase volume and become more sensitive. Learning about these boosted-sensitivity messages from the brain to the cochlea—if they're similar in humans—might help explain tinnitus and fuel experimental approaches to turn down that sensitivity.

We hear because soundwaves are converted into electrochemical signals in our ears

This science teacher video systematically walks through the biology of the outer, middle, and inner ear. The explanation starts with the auricle, an external part that funnels sound through the auditory canal, and the tympanic membrane (the ear drum), which vibrates when sounds hit it. Beyond that, as the video details, is the eustachian tube, which is connected to the back of our throats and allows air to pass in and out to equalize ear pressure.

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.

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.

Open brain surgery is not required for BCIs inserted via blood vessel injection

Synchron's brain-computer interface, the Synchron Switch, takes advantage of preexisting medical devices, such as stents and catheters. Cells grow over the device over a 90-day period, incorporating it into the vessel wall and minimizing clots.

We may be using Q-tips in our ears—even when we shouldn't—because they can stimulate pleasure nerves

People continue to use Q-tips inside their ears even though we know it's risky. Some clinicians suggest that beyond the desire to get water out, this may be because the nerve bundle called the vagus nerve, which spans from the brain to the large intestine, can be stimulated that way, causing a pleasurable sensation in other body parts including the heart, belly, or genitals.

Scientists are learning to guide your dreams using sound and touch

Researchers are using a technique called "targeted dream incubation"—where stimuli like sounds or vibrations are introduced as you drift off—to influence dream content and potentially improve creativity, memory consolidation, and PTSD treatment. With the same mechanism, companies could theoretically target sleeping consumers with brand suggestions while they're unaware and neurologically susceptible, or assist in reducing nightmares.

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.

Why surgeons implant teeth into eyes

What if the thing that restored your vision… was your own tooth? That’s exactly what happened to Brent Chapman. After 20 years without sight, a bizarre surgery using his tooth as a lens restored his vision.

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

Though little indentations form on the side of the fetus's neck at roughly nine weeks—with some formations taking place even before then—developmentally, these indentations don't become ears that allow a little one to hear until around 18 weeks.

Acoustic Vehicle Alerting Systems provide motor sounds in electric vehicles

Since 2019, various global standards have set requirements for these systems, which seek to mimic combustion-engine sounds by meeting specific sonic criteria, including sound pressure, frequency, and pitch. Sound engineers design these systems to meet these requirements, ensuring that passers-by, particularly the blind and visually impaired, can detect the presence of a vehicle.

A web of sensory neurons in the skin help filter out background sensations

The somatosensory system helps us organize and navigate our surroundings, enabling us to understand our bodies in relation to our environment and also filter out minor sensations that are basically background noise so they aren't overwhelming to our bodies. Meanwhile, viscerosensation—or internal sensation—refers to the internal sensory neuron system that conveys information from internal organs to the brain.

Ultrasound machines emit and collect high-frequency sound waves to construct images

Before its use in medical imaging, the technology was employed in World War I for submarine detection, the same way bats use sound for echolocation of obstacles. Differences in the penetrating power of different frequencies allow medical professionals to detect different structures in the body.

Squeaky toys mimic prey sounds, appealing to dogs' hunting instincts

Squeaky toys provide instant feedback and gratification, and they can also prevent boredom and improve canine dental health. Some toys contain seemingly silent squeakers that use ultrasonic technology to emit sounds only audible to dogs.

Integrated circuits come in digital, analog, or mixed types

Each type can be further divided based on application, technology, and integration level. Digital ICs are used in computer memories and microprocessors, while analog ICs process continuous signals within sensors, including temperature, light, and sound.

Retrieval cues trigger memories and emotions from long-term storage

Retrieval cues can activate specific cells in a neural network, creating a cascade of neurons that collectively make up a memory. Specific cues help regulate emotions during stress by activating positive memories.

Hear firsthand stories of prison life from those living it

"Ear Hustle"—produced inside San Quentin Rehabilitation Center (formerly known as San Quentin State Prison)—shares personal and often surprising stories of incarceration and reentry—providing listeners with an unfiltered human perspective on the US justice system.

BPPV occurs when tiny calcium particles called otoconia become dislodged

WIth this condition, formally known as benign paroxysmal positional vertigo, calcium particles that normally help the brain interpret head movement and position migrate for unknown reasons into the ear's semicircular canals, sending irregular nerve impulses to the brain, which cause intense vertigo episodes.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Metal detectors identify induced magnetic fields in conductive objects

A changing magnetic field in a transmitter coil causes an electric current to be produced in materials that conduct electricity. This current generates its own magnetic field, which can be detected by a receiver coil and transmitted to a control box, which identifies the presence and depth of an object.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

About 2,000 US babies are born annually without some portion of their limbs, potentially leading to a lifetime of pricey prosthetics.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

A pickleball's loud 'pop' sound can reach 120 decibels, which is equivalent to a hammer hitting a nail

'Silent' fireworks have gained more interest in recent years as a quieter celebratory option.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

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See images of medical cases of firework injuries shared on this 'Instagram for doctors.' (Warning: Graphic content)

Planeterrellas create artificial auroras that mimic the atmospheric displays of light by setting up an electric field between two metal balls in a jar filled with a small amount of air.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Bone marrow (soft tissue found inside certain bones) generates roughly 500 billion new blood cells each day

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

US intelligence allegedly pursued more than 600 schemes to assassinate Cuban revolutionary Fidel Castro.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.