40 Fun Facts About Audiology

Which stirrup-shaped bone in the middle ear is the smallest and lightest bone in the human body?

The stapes is the last of three tiny ossicles, passing sound vibrations on to the inner ear. Its Latin name simply means stirrup.

The decibel is named after which inventor, whose mother and wife were both deaf?

Bell is honored in the bel, a unit now seldom used on its own because nearly everyone works in tenths of it. His mother's hearing loss is what first pushed him to study acoustics.

Which Vienna composer had visitors write in notebooks to hold conversations as his hearing failed?

Beethoven never went totally deaf: in his final years he could still pick out low tones and sudden loud sounds. His 'conversation books' are now a prized record of his life.

The cochlea, the coiled organ of hearing, takes its name from the Greek word for which animal?

Snail is the sense of the Greek kokhlias behind the name, a nod to the organ's spiral shell shape. Monotremes are the notable mammals whose cochlea is not coiled.

Audiology emerged as a profession after which war sent many veterans home with hearing loss?

World War II left so many veterans with hearing loss that a new field grew up to treat them. The words audiology and audiologist have been traced in print only as far back as 1946.

Loud noise can destroy which sensory receptors in the cochlea, because humans cannot regrow them?

Hair cells are named for the tufts of stereocilia on top, fifty to a hundred on each one. Because they cannot regenerate, the hearing lost with them is gone for good.

Which passage from the middle ear to the back of the nose opens during a swallow to equalize pressure?

The Eustachian tube normally stays collapsed and gapes open on a swallow, letting middle-ear pressure match the cabin air as a plane descends.

Which condition, named from the Latin for 'to ring', makes people hear sounds with no outside source?

Tinnitus is usually described as ringing, but it can just as easily sound like clicking, buzzing, hissing or roaring.

Which nickname is given to an infection of the outer ear canal, often set off by trapped water?

Swimmer's ear can also follow a shower, since water trapped in the canal is enough to start it, especially in a humid climate.

Which funnel-shaped device was the main listening aid for deaf people before electric hearing aids?

The ear trumpet has served the partially deaf since the 17th century; the first electric aid, the Akouphone, grew out of telephone technology in the 1890s.

What is the everyday name for the tympanic membrane, the thin sheet dividing the outer and middle ear?

The eardrum is cone-shaped rather than flat, and the way it looks through a scope can reveal diseases of the middle ear hidden behind it.

What is the medical name for earwax, which comes in genetically determined wet and dry types?

Cerumen of the wet type is genetically dominant, while the dry, gray and flaky type is recessive and more common in parts of East Asia.

Which part of the brain, also vital for long-term memory, houses the primary auditory cortex?

The temporal lobe carries the auditory cortex along its upper side, partly tucked inside a deep fold called the lateral sulcus.

Which three fluid-filled loops in the inner ear sense head rotation and help keep the body balanced?

The semicircular canals sit at right angles to one another, so between them they can pick up a turn of the head in any direction.

What is the anatomical name for the visible outer flap of the ear, from the Latin for wing?

The pinna, also called the auricle, does more than funnel sound inward: its folds filter what arrives in a way that favors the pitches of human speech.

The commonly stated range of human hearing starts at 20 Hz and runs up to which limit?

20,000 Hz is the textbook ceiling, though people vary widely at the top end and a gradual loss of the highest pitches with age is considered normal.

Which chart of a hearing test plots the quietest sounds a person can hear at each pitch?

An audiogram runs pitch from left to right and loudness in decibels down the side, with a mark at the softest level the listener could detect.

What name is given to sound below 20 Hz, too low for people to hear but used by elephants and whales?

Infrasound lets whales keep in touch over distances of up to hundreds of miles, and people use it to monitor earthquakes and volcanoes.

Which false sensation of spinning is a hallmark of Ménière's disease, a disorder of the inner ear?

Vertigo traced to the inner ear or its balance nerve is called peripheral, to set it apart from the kind that starts in the brain.

What is the medical name for middle ear inflammation, a frequent cause of ear-pulling in young children?

Otitis media can leave fluid sitting in the middle ear for weeks or months after the infection itself has cleared, usually without any symptoms.

Which handheld instrument, also called an auriscope, does a clinician use to look down the ear canal?

An otoscope packs a light and a magnifying lens of about three times into its head, and it can double as a viewer for the nose and upper throat.

Which tool does a clinician hold against the skull in the Rinne and Weber hearing tests?

A tuning fork humming on the middle of the forehead should sound equally loud on both sides; hearing it louder in one ear is a clue to what kind of loss is present.

Which hearing pathway explains why a recording of your own voice sounds higher than you expect?

Bone conduction carries low pitches through the skull better than air does, so the voice you hear inside your own head is deeper and fuller than the one others hear.

What name do anatomists give the inner ear's fluid-filled network of passages and chambers?

The labyrinth is named after the Minotaur's maze of Greek myth: a rigid bony shell holds a second, membranous one, surrounded by a clear fluid called perilymph.

Which fruit gives its name to the zone on a hearing test chart where the sounds of human speech fall?

Banana is the shape that speech sounds trace on the chart, and hearing loss inside that 'speech banana' is the kind that can slow a child's speech and learning.

The incus, one of the three tiny bones of the middle ear, is named for its likeness to which tool?

Anvil is what incus means in Latin, and the bone works like one, taking vibrations from one neighbor and handing them on to the next.

What is the medical term for age-related hearing loss, which is usually most marked at higher pitches?

Presbycusis joins the Greek words for old and hearing, and it creeps up on both ears at once, progressively and irreversibly.

Which type of hearing loss, by far the most common, stems from damage to the inner ear or its nerve?

Sensorineural loss accounts for about 90% of reported hearing loss, with aging its most common cause and noise exposure the runner-up.

What term describes drugs, including some antibiotics and chemotherapy agents, that can damage the inner ear?

Ototoxic drugs are still prescribed for very serious illnesses despite the risk, and the harm they do can be either temporary or permanent.

Which technique of pinching the nose shut and blowing out do divers and flyers use to clear their ears?

The Valsalva maneuver is named after Antonio Maria Valsalva, an anatomist at Bologna whose main scientific interest was the human ear.

Graeme Clark led a team that built a multi-channel cochlear implant, the 'bionic ear', in which country?

Australia's government helped fund the push to sell it commercially, and Clark's design became the first multi-channel implant to win US FDA approval, in 1985.

Which Hungarian-born physicist won the 1961 Nobel Prize in Medicine for showing how the cochlea works?

Georg von Békésy used strobe photography and flakes of silver as markers to watch a wave ripple along the inner ear's membrane as sound arrived.

Which structure inside the cochlea, found by an anatomist in 1851, is the receptor for hearing?

The organ of Corti lines up its sensory receptors in tidy rows along the spiral: three outer rows and a single inner one.

Which faint sounds made by a healthy inner ear, first shown by David Kemp, are used to screen newborns?

Otoacoustic emissions were predicted by the astrophysicist Thomas Gold in 1948, thirty years before anyone managed to record them, and they vanish when the inner ear is damaged.

Which small part inside many hearing aids picks up sound magnetically from an audio induction loop?

A telecoil takes its name from 'telephone coil', and it can also catch the magnetic signal given off by the speaker of a phone held to the ear.

Which name, first defined by Colin Cherry, describes the knack of following one voice in a noisy room?

The cocktail party effect grew out of 1950s research into air traffic controllers, who struggled to pick one pilot's voice from many on a single loudspeaker.

Which term, coined in 2001, describes strong negative reactions to sounds such as other people eating?

Misophonia loosely means 'hate of sound', yet loudness is not the issue: the reaction is set off by a sound's particular pattern or its meaning to the listener.

The 1952 Sonotone 1010 hearing aid stretched its battery life by adding which new electronic part?

A transistor was small, ran cooler and needed less power than the hot, fragile vacuum tubes it worked beside, and by 1953 hearing aids were among the few products using one.

On the logarithmic decibel scale, a sound 20 decibels above another has its power multiplied by what?

100 times is right because every 10 decibels multiplies power tenfold, so two such steps make a hundredfold jump rather than a doubling.

Which tiny calcium carbonate crystals in the inner ear help the body sense gravity and acceleration?

Otoliths that break loose and drift around the inner ear are the usual cause of a common kind of dizziness brought on by changes in head position.