journey into the world of hearing

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How Do We Hear?

Hearing depends on a series of complex steps that change sound waves in the air into electrical signals. Our auditory nerve then carries these signals to the brain. Also available:  Journey of Sound to the Brain , an animated video.

• Sound waves enter the outer ear and travel through a narrow passageway called the ear canal, which leads to the eardrum.
• The eardrum vibrates from the incoming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are called the malleus, incus, and stapes.
• The bones in the middle ear amplify, or increase, the sound vibrations and send them to the cochlea, a snail-shaped structure filled with fluid, in the inner ear. An elastic partition runs from the beginning to the end of the cochlea, splitting it into an upper and lower part. This partition is called the basilar membrane because it serves as the base, or ground floor, on which key hearing structures sit.
• Once the vibrations cause the fluid inside the cochlea to ripple, a traveling wave forms along the basilar membrane. Hair cells—sensory cells sitting on top of the basilar membrane—ride the wave. Hair cells near the wide end of the snail-shaped cochlea detect higher-pitched sounds, such as an infant crying. Those closer to the center detect lower-pitched sounds, such as a large dog barking.
• As the hair cells move up and down, microscopic hair-like projections (known as stereocilia) that perch on top of the hair cells bump against an overlying structure and bend. Bending causes pore-like channels, which are at the tips of the stereocilia, to open up. When that happens, chemicals rush into the cells, creating an electrical signal.
• The auditory nerve carries this electrical signal to the brain, which turns it into a sound that we recognize and understand.

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What Did You Say? An Unexpected Journey Into the World of Hearing Loss Paperback – March 12, 2012

There is a newer edition of this item:.

Hammond points out that she is not a professional hearing specialist, so her first important message is that people who experience any ear-related symptoms ''must consult their physician or ear specialist for proper diagnosis and treatment.'' From there, she provides organized, easy-to-understand facts and details that enable readers to have educated discussions with their medical professionals. Weaving together her own experiences with a wealth of information, Hammond's wisdom and insights are invaluable, and her story is one that needs to be shared.

• Print length 374 pages
• Language English
• Publisher Two Harbors Press
• Publication date March 12, 2012
• Dimensions 5.5 x 1 x 8.5 inches
• ISBN-10 1937928160
• ISBN-13 978-1937928162
• See all details

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About the author.

She lives in Minneapolis, Minnesota.

Product details

• Publisher ‏ : ‎ Two Harbors Press; 1st edition (March 12, 2012)
• Language ‏ : ‎ English
• Paperback ‏ : ‎ 374 pages
• ISBN-10 ‏ : ‎ 1937928160
• ISBN-13 ‏ : ‎ 978-1937928162
• Item Weight ‏ : ‎ 1.14 pounds
• Dimensions ‏ : ‎ 5.5 x 1 x 8.5 inches
• #85,782 in Motivational Self-Help (Books)
• #151,400 in Memoirs (Books)

About the author

Monique e. hammond.

MONIQUE HAMMOND graduated from the University of Minnesota, College of Pharmacy, with high distinction. She is a registered pharmacist and has worked in health care in Europe, the United States, and Australia.

Her priorities have always been patient safety and advocacy as well as health education and disease prevention.

Monique is a powerful public speaker and a staunch advocate for those with hearing loss. She is an industrial consultant on work-related hearing issues and continues to work with community and support groups. Her mission is “to keep people hearing better, longer.” Visit her at www.moniquehammond.com

Monique has also done extensive public speaking on health issues and has published health columns and articles both at home and overseas. She produced and hosted her own health-focused public access TV show Over–the-Counter in Minneapolis.

Monique entered the world of hearing loss in fall 2005 when — in a matter of four hours — she went totally deaf in her left ear. This life-changing event put her on track to research issues regarding ear and hearing disorders and to work on behalf of people with hearing loss.

Monique was appointed by the governor of Minnesota to the MCDHH (Commission for Deaf, Deafblind and Hard-of-Hearing Minnesotans). She was vice-chair and finished two three-year terms. She has served on multiple hearing-related advisory committees and was president of HLAA TC (Hearing Loss Association of America, Twin Cities). Monique is a member of the ATA (American Tinnitus Association) and HLAA National and local chapters.

Following her family’s assignment to Australia, Monique wrote Ride the Wave, a book on the relocation challenges for American families working overseas. A local university used the text as required reading for international business classes. She also contributed articles to Mobility, the magazine of the Employee Relocation Council.

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About the company

Investors & financials, careers at sonova, choose your country, step inside the world of hearing, sonova’s world of hearing stores are making innovative audiological care accessible to all.

Anyone can walk right into the Boots Hearingcare World of Hearing store in Chelmsford in the UK. The whole storefront opens onto a busy shopping mall. A large sign advertises free hearing health checks. Digital displays and a touchscreen table catch the eyes of passers-by. At the threshold, ‘Welcome’ is printed on the floor.

The unit next door is occupied by a leading mobile phone brand. Both have bright and inviting interiors where shoppers can browse the latest technology and get expert advice. It’s an environment that makes getting a hearing aid feel very natural — friendly and personal, not clinical. This is how Sonova’s World of Hearing stores are changing the image of hearing care, all over the world.

Dedicated to the delight of hearing

Launched in 2019, the World of Hearing concept embodies Sonova’s commitment to bring the delight of hearing to people everywhere, and the company’s relentless pursuit of innovation. 

As a commercial center within reach of a large population, Chelmsford is an ideal location for a flagship store. This store opened in November 2022 and compliments other Boots Hearingcare stores in the region through a wider selection of hearing solutions and services as well as more specialized audiological facilities.

Experience the difference 

Hearing Wellness Advisors like Hari Jones welcome visitors to the store. Hari can also perform some audiological services, including hearing tests. If there are signs of hearing loss, Hari arranges a full hearing assessment with an audiologist. 

When a customer needs a hearing aid, the store has an Experience Room where they can see how different models perform in a variety of virtual situations, like a concert or noisy restaurant. As Hari explains, being able to experience the difference a hearing aid makes is a huge help in overcoming reluctance about wearing one. “When people understand what they should be hearing, they realize how much they’ve been missing out on,” she says.

Fully focused on the customer

The clinical work is carried out in the consulting rooms at the back of the store. The store’s high profile means Saarah Alam and the other audiologists are busy every day. “Someone may have hearing at the back of their mind so it’s good they can just come in without an appointment when they are out shopping,” says Saarah.

Saarah’s consulting room demonstrates the benefits of the World of Hearing’s purpose-built environment. It’s a calm, private space designed for audiological care. One corner contains a soundproofed booth. Above the desk is a widescreen TV that Saarah uses to talk customers through their hearing assessment. When Saarah worked in other clinics her room was also a repair center and warehouse. Hari and her colleagues, Hearing Wellness Advisors, take care of all that, which allows the audiologists to focus entirely on customers.

For the whole hearing journey 

People of all ages are responding enthusiastically to the World of Hearing concept. Some even travel further to come here instead of stores that are closer to home. “Everyone loves the store,” says Saarah. “Our older customers prefer the layout and more and more young people are getting their hearing checked out who probably wouldn’t do that if we weren’t here.” It’s an enjoyable place to work too. “People are so interested to come in and see what we do,” says Hari.

Find your nearest store

Sonova has World of Hearing stores on four continent and more than 3,900 audiological clinics and stores worldwide. Find your nearest store here .

About World of Hearing

One of the recent openings of a World of Hearing store was in Toronto, Canada. Watch the video to get an impression of Darryl Sittler, Canadian hockey legend, visiting the store.

With a pioneering store concept in the field of hearing solutions, the Sonova Group is setting new standards in the industry. The focus is on interactive experiences, latest product innovations and services for complex hearing problems such as tinnitus. 

The world's first audiology store based on this concept was opened in December 2018 in Dordrecht, the Netherlands, by Sonova brand Schoonenberg. Since then, the number of World of Hearing stores has grown considerably, establishing this store concept as a successful global model on four continents.

Seeing Voices

In Seeing Voices, Dr. Sacks launches a journey into the world of Deaf culture, and the neurological and social underpinnings of the remarkable visual language of the congenitally deaf.

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American Sign Language (ASL) Deafness Hearing Neurology Sign Language

“This book will shake your preconceptions about the deaf, about language and about thought. Sacks [is] one of the finest and most thoughtful writers of our time.”

— Los Angeles Times Book Review

“I had never thought about what it might mean to be deaf, to be deprived of language, or to have a remarkable language (and community and culture) of one’s own. Up to this point, I had mostly thought and written about the problems of individuals–here I was to encounter an entire community.” — Oliver Sacks

With Seeing Voices, Dr. Sacks launches on a journey into the world of the deaf, which he explores with the same passion and insight that have illuminated other human conditions for his readers everywhere.

Seeing Voices begins with the history of deaf people in the United States, the often outrageous ways in which they have been seen and treated in the past, and their continuing struggle for acceptance in a hearing world. And it examines the amazing and beautiful visual language of the deaf–Sign–which has only in the past decade been recognized fully as a language–linguistically complete, rich, and as expressive as any spoken language.

The existence of this unique alternative mode of language, writes Dr. Sacks, has wide-ranging implications for those in the hearing world as well, for it “shows us that much of what is distinctly human in us–our capacities for language, for thought, for communication, and culture–do not develop automatically in us, are not just biological functions, but are, equally, social and historical in origin; that they are a gift–the most wonderful of gifts–from one generation to another….The existence of a visual language, Sign, and of the striking enhancements of perception and visual intelligence that go with its acquisition, shows us that the brain is rich in potentials we would scarcely have guessed of, shows us the almost unlimited resource of the human organism when it is faced with the new and must adapt.”

Sign is not only a language but the very medium of deaf culture. It stands at the center of the extraordinary social and political movement for deaf rights, which gained international attention with the uprising of deaf students at Gallaudet University in March 1988. In Part III of Seeing Voices, Dr. Sacks gives an eyewitness account of the revolt, and the students who organized it, and considers its impact on a new generation of deaf children.

Seeing Voices is a fascinating voyage into a strange and wonderful land, and along the way Oliver Sacks ponders the nature of talking and teaching, child development, the development and functioning of the nervous system, the formation of communities, worlds, and cultures, and the interface of language, biology, and culture.

📷 Dr. Sacks, as featured on the back cover of Seeing Voices .

“A remarkable book, penetrating, subtle, persuasive….[It] will likely become a classic.” — Keith W. Spoeneman, St. Louis Post-Dispatch

“One cannot read more than a few pages of Sacks without seeing something in a new way. His breadth of understanding and expression seem limitless….His subject matter is compelling, and his writing is powerful in its understatement.” — Lee Dembart , Kansas City Star

“Sacks is a profoundly wise observer…. Seeing Voices is fascinating and richly rewarding.” — Andrea Barrett , Cleveland Plain Dealer

Related Books

The Mind’s Eye

Sacks explores some of the most fundamental facets of human experience–how we see in three dimensions, and how we represent the world internally when our eyes are closed.

The Island of the Colorblind

An exploration of a society with congenital colorblindness, this book is a meditation on islands and the strange neurologic malady on Guam which resembles Parkinsonism and Alzheimer’s.

An Anthropologist on Mars

Seven paradoxical tales of patients adapting to neurological conditions including Asperger’s, Tourette’s, acquired colorblindness, and the restoration of vision after congenital blindness.

Photo by Bill Hayes

“I rejoice in the knowledge of my biological uniqueness and my biological antiquity and my biological kinship with all other forms of life."

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What Did You Say?: An Unexpected Journey into the World of Hearing Loss

Nothing prepared Monique Hammond for her own sudden hearing loss, and her questions to medical professionals often left her with more questions than answers. What Did You Say? is the book she wishes she had when she was coping with and trying to understand her own hearing loss.

Hammond points out that she is not a professional hearing specialist, so her first important message is that people who experience any ear-related symptoms ''must consult their physician or ear specialist for proper diagnosis and treatment.'' From there, she provides organized, easy-to-understand facts and details that enable readers to have educated discussions with their medical professionals. Weaving together her own experiences with a wealth of information, Hammond's wisdom and insights are invaluable, and her story is one that needs to be shared.

Updated: July 5, 2013

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A baby's journey into the hearing world

It was the best option, say parents James and Kristin Van Winkle of Washington, Iowa, after months of testing and teaching by University of Iowa doctors, therapists, and audiologists, who had worked with Madison virtually since birth. The first indication of trouble came when Madison failed to pass a newborn screening of her auditory response at just 2 days old.

We came back two days later and she didn’t pass it,” James says. “That’s when our pediatrician referred us to the University of Iowa.”

At 3 months old, Madison was fitted with hearing aids. The extent of her hearing loss, however, was still unknown. She and her parents started learning simple sign language, not knowing what the future would bring.

As her first birthday neared, Madison’s otolaryngologist, Marlan Hansen, MD, started talking with her parents about cochlear implants—instruments that translate sound into electronic signals and stimulate a person’s auditory nerve.

“We probably would have been a year or more into Madison’s growth before we noticed anything with her hearing,” James says. “That really underscored the importance of early screening for us.”

An estimated 92 percent of babies born in the U.S. are screened for hearing loss before they reach 1 month of age, according to the American Speech-Language-Hearing Association. In Iowa that number is closer to 98 percent, says Bruce Gantz, MD, chair of the University of Iowa Department of Otolaryngology—Head and Neck Surgery and co-director and founder of the Iowa Cochlear Implant Research Center. Nationally, three of every 1,000 children in the United States may be born with some level of hearing loss.

Today Madison is a normal 3-year-old girl who was mainstreamed into preschool and joined in without issue, her parents say. She even sings and dances along to songs on the radio or that she recognizes on some programs.

“We knew that cochlear implants had varying levels of response, so we didn’t really have any kind of expectations,” James says. “But we really didn’t think she’d get the implants and then she’d be singing.”

Hansen, co-director of the Iowa Cochlear Implant Research Center, says there are no “typical” results expected with cochlear implants, only expectations of some level of improved hearing.

For patients like Madison, who are implanted early in life, picking up “normal” speech patterns is much easier, he says. Younger patients typically develop normal language, normal speech, and normal learning patterns, he says.

“There’s good evidence that the earlier you put in the cochlear implant, the more quickly the patient will develop those skills,” Hansen says.

Gantz agrees, but adds that the results of a behavioral audiogram also are important in determining a child’s need for cochlear implants, and those results aren’t reliable until a child is about 7 to 8 months old.

“For children there is a critical period when they get significant information from the brain, and the earlier you implant them the closer they get to age-appropriate hearing,” he says. “Children up to the age of 4 can benefit as well as children implanted at 1.”

A cochlear implant has several parts—an external microphone that picks up sound; speech processor that translates sound into electrical signals; and magnetic headpiece that transmits the signals to an implanted receiver just under the skin. The receiver delivers the information to an array of electrodes (surgically inserted in the cochlea), which distribute them along the auditory nerve. The stimulated nerve sends the information to the brain, where it is perceived as sound—a baby’s cry or a Mozart concerto, for example

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Journey into the world of hearing

Cochlear fluids

Authors: Benjamin Delprat Contributors: Sam Irving

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The cochlear canals contain two types of fluid: perilymph and endolymph. Perilymph has a similar ionic composition as extracellular fluid found elsewhere in the body and fills the scalae tympani and vestibuli. Endolymph, found inside the cochlear duct (scala media), has a unique composition not found elsewhere in the body.

Composition of the cochlear fluids

A remarkable characteristic of the cochlea is the unique composition of endolymph. This liquid fills the scala media, and is very rich in potassium (150mM), very poor in sodium (1mM) and almost completely lacking in calcium (20-30 µM).

There are two types of perilymph: the perilymph of the scala vestibuli, and that of the scala tympani. Both have a composition similar to cerebro-spinal fluid (CSF): rich in sodium (140mM) and poor in potassium (5mM) and calcium (1.2mM). The perilymph in the scala vestibuli comes from blood plasma across a hemto-perilymphatic barrier, whereas that of the scala tympani originates from CSF.

Endolymph is created from perilymph.  The endocochlear potential is the sum of two potentials: a positive potential caused by active secretion of K+ by the stria vascularis (120mV) and a negative potential created by the passive diffusion of K+ ions from the hair cells (40mV), which can be visualised after an anoxia.

Note that the ionic composition of endolymph develops prior to the endocochlear potential. In fact, in the mouse, endolymphatic ion concentrations are finalised during the first postnatal week. In comparison, the mouse endocochlear potential doesn’t develop until the second postnatal week and doesn’t reach its final value until the third week after birth.

Composition and properties of the two cochlear fluids

Why endolymph?

It appears that the cochlea has found a way of regulating potassium flow without expending any energy (ATP). Generally speaking, if an ion enters a cell in a passive way, it requires an active mechanism to leave it, and vice versa.

Only the apical pole of the hair cells bathes in the potassium-rich endolymph, which has a positive potential of 80mV. K+ ions therefore enter these cells passively, as there is more potassium in the endolymph than in the hair cell and the latter have a resting potential of -60mV, which favours an influx of K+. These ions also leave the hair cells in a passive manner, due to the higher concentration of K+ ions inside the hair cell, compared to outside of the cell body bathed in perilymph. This all results in a significant saving of ATP by the hair cell.

Stria vascularis

The stria vascularis, a complex epithelial structure composed of various cell types, produces endolymph and releases it into the cochlea. The basal and marginal cells are true epithelial cells, whereas the intermediate cells are ‘melanocyte-like’. Intricate vasculature provides the oxygen and nutrients needed for the stria vascularis to function correctly.

Structure of the stria vascularis (transmission electron microscopy) Highly vascular (C), the stria vascularis is composed of three cell types:

• Marginal cells (M), which line the endolymphatic canal and have an essential role in ion exchange
• Intermediate cells (I), which are rich in the pigment melatonin
• Basal cells (B).

This task is carried out by Na, K-ATPase, which is expressed in the membrane of intermediate and marginal cells. Furthermore, the co-transporter NKCC1, expressed in the membrane of marginal cells, is also involved in this regulation by using the sodium gradient generated by the Na, K-ATPase to cause the ingression of potassium into the marginal cell.The influx mechanism of potassium ions into the marginal cells is very efficient, using a single ATP molecule to cause the influx of 5 molecules of potassium (2 using Na, K-APTase and 3 using the co-transporter NKCC1).

Finally, chlorine ions, which enter the cell at the same time as sodium and potassium ions via the co-transporter NKCC1, are expelled by CIC-K chlorine channels associated with their regulating beta-subunit, barttine. Mutations in barttine expression are responsible for Bartter’s syndrome; causing both tubulopathy and hearing loss. Potassium is finally secreted into scala media via KCNQ1 potassium channels associated to their regulating subunit KCNE1. Mutations in these two genes give rise to Jervell and Lange-Nielsen syndrome, causing bilateral hearing loss and a long cardiac QT.

Last update: 11/10/2016 8:13 pm

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Journey into the world of hearing

Perception: overview

Authors: Antoine Lorenzi Marie Camilleri Contributors: Sam Irving

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Auditory perception is our brain’s interpretation and understanding of our sound environment. Because absolute silence exists only in a vacuum, we are constantly confronted with sound sources, either useful or unwanted, that can occur simultaneously or one after the other. How do we sort through all of these sounds? Put simply, our ears code the different sound messages that reach us, and our brain carries out the task of reconstructing and sorting them using attention and memory (see also “How do I hear?”). This allows us, for example, to recognise different voices, to understand speech, to follow a conversation when there are other sounds around, or to distinguish between different elements of a complex sound and therefore enjoy music!

Auditory sensation

Foundamental characteristics of the  auditory sensation are: the loudness, the pitch and the timbre.

• Loudness is the sensation of intensity: a sound is loud or weak,
• Pitch is the sensation of fréquency: a sound is high or low.
• Timbre is the charcteristic, which allows us to differentiate between sounds of same pitch and loudness: everyone's voice, every music instruments has its specific and recognizable timbre (see " Music perception ")

Binaural hearing

When both of our ears are stimulated, the difference between the intensity and the frequency at each ear, over time, has a major effect on sound perception: This is stereophonic hearing, which is very important, and we will come back to it when we talk about listening to music.  Binaural hearing is essential for localizing sound sources.

Loudness elevation with binaural hearing

When the same sound reaches the two ears at the same time (as when wearing headphones) the perceived loudness is greater (sound #2) than when it reaches only one ear (sounds #1 or 3).

Listen to the 3 sounds (preferably with headphones)

Sound localization in the horizontal plane

With only one ear it would be very difficult to guess from where the sound is coming. Differences in loudness and time between the two ears allow us a pretty good sound localization in the horizontal plane (see animated drawing below).  In the vertical and medial plane, localization is much less precised.

When a sound source is placed to the side, the sound wave, which decreases with distance, arrives at the exposed ear first (here, the left ear), before working its way around the head to the other ear (here, the right ear).

This means that the sound arrives at each ear at a slightly different time and with different intensity. The brain uses these differences to determine the location of sound in space. In this example, although the subject has his eyes closed, he is able to say that the loudspeaker is on the left. On the other hand, it’s much harder for him to tell how far away it is.

Analysis of an auditory scene

In reality, we are constantly bombarded with multiple sound sources. The analysis of an auditory scene depends upon the properties of binaural hearing that we have just described, as well as the frequency information that comes from different sound sources.

The animation below shows how we are able to analyse, organise and reconstitute the different sound elements of our environment.

When the man first enters the room, he perceives a cacophonic mixture of sound: the sum of all of the sound sources in the room … little by little, he recognises each of the sound sources (the radio, the fan, the purring cat, the clock and the telephone), and he goes towards the ringing telephone, which he considers a priority. During the following phone conversation, our man will temporarily ‘forgets’ the other sound sources.

A similar process allows us to ignore the background chatter and music of a cocktail party, and focus our attention on the person that we are speaking to.

Last update: 08/10/2016 4:55 pm

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The Protesters and the President

Over the past week, thousands of students protesting the war in gaza have been arrested..

Hosted by Michael Barbaro

Featuring Jonathan Wolfe and Peter Baker

Produced by Diana Nguyen ,  Luke Vander Ploeg ,  Alexandra Leigh Young ,  Nina Feldman and Carlos Prieto

Edited by Lisa Chow and Michael Benoist

Original music by Dan Powell and Marion Lozano

Engineered by Chris Wood

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Warning: this episode contains strong language.

Over the past week, students at dozens of universities held demonstrations, set up encampments and, at times, seized academic buildings. In response, administrators at many of those colleges decided to crack down and called in the local police to detain and arrest demonstrators.

As of Thursday, the police had arrested 2,000 people across more than 40 campuses, a situation so startling that President Biden could no longer ignore it.

Jonathan Wolfe, who has been covering the student protests for The Times, and Peter Baker, the chief White House correspondent, discuss the history-making week.

On today’s episode

Jonathan Wolfe , a senior staff editor on the newsletters team at The New York Times.

Peter Baker , the chief White House correspondent for The New York Times covering President Biden and his administration.

Background reading

As crews cleared the remnants of an encampment at U.C.L.A., students and faculty members wondered how the university could have handled protests over the war in Gaza so badly .

Biden denounced violence on campus , breaking his silence after a rash of arrests.

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The Daily is made by Rachel Quester, Lynsea Garrison, Clare Toeniskoetter, Paige Cowett, Michael Simon Johnson, Brad Fisher, Chris Wood, Jessica Cheung, Stella Tan, Alexandra Leigh Young, Lisa Chow, Eric Krupke, Marc Georges, Luke Vander Ploeg, M.J. Davis Lin, Dan Powell, Sydney Harper, Mike Benoist, Liz O. Baylen, Asthaa Chaturvedi, Rachelle Bonja, Diana Nguyen, Marion Lozano, Corey Schreppel, Rob Szypko, Elisheba Ittoop, Mooj Zadie, Patricia Willens, Rowan Niemisto, Jody Becker, Rikki Novetsky, John Ketchum, Nina Feldman, Will Reid, Carlos Prieto, Ben Calhoun, Susan Lee, Lexie Diao, Mary Wilson, Alex Stern, Dan Farrell, Sophia Lanman, Shannon Lin, Diane Wong, Devon Taylor, Alyssa Moxley, Summer Thomad, Olivia Natt, Daniel Ramirez and Brendan Klinkenberg.

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Jonathan Wolfe is a senior staff editor on the newsletters team at The Times. More about Jonathan Wolfe

Peter Baker is the chief White House correspondent for The Times. He has covered the last five presidents and sometimes writes analytical pieces that place presidents and their administrations in a larger context and historical framework. More about Peter Baker

Luke Vander Ploeg is a senior producer on “The Daily” and a reporter for the National Desk covering the Midwest. More about Luke Vander Ploeg

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