The Hearing-Loss Guide: Useful Information and Advice for Patients and Families
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The Hearing-Loss Guide: Useful Information and Advice for Patients and Families
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Overview
Prompted to write this book by a patient who thought the reality of hearing loss and its associated problems could only be truly understood by someone with personal experience, audiologist John M. Burkey gathered information from his own patients and their spouses. The Hearing-Loss Guide presents their candid recommendations for anyone who suffers hearing loss, as well as families, friends, and co-workers.
The author opens with chapters on the basics of hearing loss, hearing aids and other devices, and treatments. He then turns to his patients, who discuss coping with hearing loss, the real-life consequences of losing hearing, how to get help, adapting to a hearing aid, and other useful topics. Family members also offer valuable advice. A resource guide completes this indispensable volume.
Product Details
| ISBN-13: | 9780300213539 |
|---|---|
| Publisher: | Yale University Press |
| Publication date: | 03/01/2015 |
| Series: | Yale University Press Health & Wellness |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 288 |
| Sales rank: | 1,046,098 |
| File size: | 2 MB |
About the Author
Read an Excerpt
The Hearing-Loss Guide
Useful Information and Advice for Patients and Families
By John M. Burkey
Yale UNIVERSITY PRESS
Copyright © 2015 John M. BurkeyAll rights reserved.
ISBN: 978-0-300-21353-9
CHAPTER 1
The ABCs of Hearing Loss
Sam had no idea what to expect when he went to the ear doctor. He was pretty sure, however, that the experience wouldn't be good. He didn't ask to be there, didn't want to be there, and was rather vocal in his opposition. Nevertheless, others had insisted Sam be checked, leaving him little recourse. His last doctor visit had been a painful fiasco, and Sam feared more of the same. This was all understandable, because Sam was three years old, and his previous medical procedure had been a vaccination at the pediatrician's office. Despite his fear and more than a little screaming, Sam unexpectedly found his ear examination and hearing evaluation to be not only painless but fun. The shiny sticker and ticket he got for a free ice cream cone at the local McDonald's were unanticipated bonuses.
Carol approached her hearing evaluation more calmly than Sam, but she had no more idea of what to expect. She didn't know what tests would be performed, their purpose, how long they would take, or how to interpret the findings. There was nothing in her schooling, her career as a secretary, her forty years of marriage, or her being a parent and grandparent that provided helpful insights related to the ear. The workings of the ear were a mystery. The variety of things that could go wrong was a bigger mystery.
Confronted by hearing loss, even professionals such as bankers, lawyers, managers, university professors, and engineers can find themselves unprepared. Their training is in areas unrelated to hearing, making it necessary for them to start at the beginning. Since the beginning for many is to have their ears checked by a professional, the first thing to do here is to provide an overview of this process.
An Examination of the Ear
Like so much in life, an examination of the ear starts with paperwork. A history questionnaire is customary and usually asks for a statement of the problem, time of onset, current medications, relevant family history, as well as whether there has been noise exposure, pain, ear infections, dizziness, or other medical concerns. The doctor will then ask additional questions to clarify and build on the information presented. This history is the foundation for everything that follows. The better history a patient can provide, the easier it is for the doctor to know how best to proceed.
Looking at the Ear
Looking in the ear canal is typically the next step in a hearing evaluation. A doctor, audiologist, nurse, or other medical professional does this with a device called an otoscope. The otoscope is little more than a fancy flashlight with a magnifying lens that makes it possible for the user to better view the ear. A more high-tech version is called a video otoscope. As the name implies, it includes a miniature camera that can display the captured images on a video monitor. More specific—and a bit scary sounding—is an operating and diagnostic microscope. This specialized magnifier may sometimes be used in place of an otoscope, because it provides stereoscopic vision during an ear examination as well as giving the best view for wax removal and other procedures. If a doctor mentions wanting to look in the ear with a microscope, this useful but harmless magnifier is the tool employed.
With the proper tool in hand, what can a professional see when looking into the ear? The answer is: less than most people think. The ear canal that the otoscope light shines into is about one inch long and ends with the eardrum (figure 1). It may be possible to see earwax, swelling, infection, or some other peripheral problem. More often than not, however, an observer sees a perfectly normal looking ear canal and eardrum. A healthy eardrum is pearly gray in color and somewhat translucent, like wax paper, limiting the view beyond. The dilemma is that there is a lot more to the ear than only the visible ear canal and eardrum.
The ear consists of several parts that work together to allow a person to hear. All are important. The visible outer portion of the ear (the pinna) collects and funnels sound into the ear canal. On examination a physician will usually perform a cursory inspection of the pinna to rule out congenital deformity, infection, or even skin cancer. An ENT physician's focus rarely lingers here, since nearly all hearing-related problems lie deeper.
Incoming sound in a normally functioning ear vibrates the eardrum, and these vibrations are then transferred through the three small middle-ear bones (the malleus, incus, and stapes—also known, respectively, as the hammer, anvil, and stirrup) to the inner ear. Collectively these bones are called the ossicles, and the air-filled space they occupy between the eardrum and the inner ear is called the middle ear. A physician can usually get a very good view of the eardrum, which will reveal if there is a perforation, scarring, or other abnormality that might impede function. Fluid or infection behind the eardrum can also usually be discerned even though the view through the eardrum is not good. Problems with the ear bones aren't likely to be visible.
Another structure important to the function of the ear is the Eustachian tube. This tube equalizes the pressure between the ear and the outside world. Scuba divers, air travelers, and even people who drive through the mountains may experience their ears "popping" as the Eustachian tube does its job. A nonfunctional Eustachian tube can result in pain, reduced hearing, an ear feeling plugged, and a variety of chronic ear problems. Physicians cannot see a Eustachian tube problem directly, but they can infer it when unequal pressure visibly pulls an eardrum back from its normal shape.
The small snail-shaped portion of the inner ear visible in figure 1 is called the cochlea, which houses thousands of sensory cells responsible for hearing. Incoming sound vibrations stimulate some or all of these cells. Once stimulated, they create an electrical signal that is sent along the auditory nerve to the brain. During an evaluation the function of the cochlea is usually assessed with a hearing test.
The vestibular portion of the inner ear is responsible for detecting body motion and maintaining balance. If a person moves forward, the fluids in the vestibular system of both ears are pushed back, stimulating the balance nerves and creating the sensation of linear acceleration. If a person turns, the fluid in one ear is pushed forward while in the other ear it is pushed back. The resulting difference in stimulation between ears is experienced as spinning. Because the hearing and balance portions of the inner ear are closely related, a problem affecting one part may affect the other. Consequently, a hearing test is routinely done when dizziness or balance difficulties are reported.
Types of Hearing Loss
Hearing loss is divided into three general categories based on what goes wrong. The first involves anything that prevents or blocks sound from getting to the inner ear. A few examples might include an ear canal filled with earwax, a broken eardrum that cannot vibrate properly, or an ear bone damaged from disease, trauma, or infection. These types of hearing losses are termed conductive since they occur when sound is not conducted, or not conducted efficiently, to the inner ear. Fortunately, conductive losses usually represent a mechanical problem that has the potential for correction or improvement. Earwax can be removed, an eardrum can be patched or reconstructed, and a damaged ear bone can be replaced with a prosthesis. A conductive hearing loss is the type people most want to have and physicians most want to find.
The majority of hearing losses, however, are due to damage in the inner ear. These are termed sensorineural. With very few exceptions, they are permanent. Sensorineural hearing loss can be caused by excessive noise exposure, trauma, disease, infection, heredity, toxicity, and several of the maladies that accompany aging. People often talk about "nerve loss" or "nerve damage" when referring to a sensorineural hearing loss. These terms can be somewhat misleading, however, because sensorineural hearing loss is twofold in nature. The problem may be due to damaged, nonfunctional, or missing sensory cells that are responsible for detecting or enhancing sound to make it audible. Hearing aids are the most common recommendation for these sensory hearing losses. A sensorineural hearing loss may also be the result of damaged nerve fibers. Auditory information becomes lost on the way to the brain as a result of this neural damage. Sounds and speech go missing—often unpredictably. This neural component explains how speech might be heard but not understood and why hearing aids sometimes provide only a limited benefit.
The final type of hearing loss is termed mixed. This loss is simply a combination of the two types previously described. A person can have sensorineural loss from noise exposure that is compounded by an ear canal full of wax. A soldier exposed to a bomb blast may experience ruptured eardrums as well as inner-ear damage from the trauma. If the conductive portion of the loss (in these cases the earwax and ruptured eardrums) can be overcome, then the remaining loss will be considered sensorineural.
Testing the Ear
Evaluation of a hearing loss requires more than a history and physical examination. Tests are also needed. These can be done to confirm or rule out a hearing loss, to quantify the severity of a loss, or to differentiate the types of hearing loss just described. Not all hearing losses are alike. A person may have a very slight problem that only prevents hearing the quietest sounds. Understanding normal speech may not be affected unless someone is speaking extremely softly or from a distance. In contrast, another person may have a more significant hearing loss that makes all but outrageously loud sounds inaudible. The majority of people with hearing loss fall somewhere in between these extremes. Hearing loss can occur across a wide range of frequencies or be focused in either the high or low pitches. High-pitched hearing losses tend to be more common. The tests routinely used to sort this all out are described next.
Basic Hearing Test Battery
A routine hearing evaluation includes four tests that are done in a quiet, soundproof room. Together they are known as the audiometric or comprehensive test battery. This may on the surface sound daunting, but all of the parts combined take only about fifteen minutes. Pure-tone air-conduction testing is the first part and involves a patient listening for beeps while wearing headphones or insert earphones. Many people are familiar with this beep test from a kindergarten hearing screening or industrial hearing test. The patient's task is to push a button, raise a hand, say "yes," or respond in some other way whenever a beep is heard. The goal is to find the softest sound a person can hear (the hearing threshold) across a range of pitches. The results are then graphed on a form called an audiogram.
A different measure of hearing threshold is obtained using two-syllable words, such as baseball or hotdog. A patient is asked to repeat the words as they are presented at quieter and quieter levels, in order to find the softest level where they can be understood. This speech reception threshold (SRT) should agree closely with the average threshold for the beeps. If they do not agree then at least one of the thresholds obtained is likely wrong and one or both of these tests are repeated until the discrepancy can be explained.
Separate from how quiet a person can hear is how clearly something can be heard once it is loud enough. Some people with hearing loss understand very well if the volume is raised. Others cannot hear clearly regardless of the volume; sounds and voices may seem distorted, like they are being played through a broken speaker. The third part of the hearing test battery provides a measure of the extent to which this might be an issue. Patients are asked to repeat single-syllable words that are presented well above an individual's hearing threshold. The percentage correct is then recorded. This measure of hearing clarity is called speech discrimination or word recognition score (WRS) testing.
The final part of the hearing test battery is known as pure-tone bone-conduction testing. The patient again listens for beeps, making it clear when they are heard. The difference from the air-conduction testing is in the kind of headphone used and where it is placed. In bone-conduction testing a small device called a bone oscillator is placed over the bone behind the ear. The oscillator sends sound vibrations through the skull to directly stimulate the inner ear. If a person hears poorly during air-conduction testing but well in the bone-conduction test, then the difference between the two (the air-bone gap) is the amount of sound that is lost on the way to the inner ear. This is the amount of conductive loss. If a person demonstrates the same amount of hearing loss during both air- and bone-conduction testing, then no sound is being lost as it passes through the ear canal, eardrum, and ear bones. The hearing loss in this case is all sensorineural.
The units of loudness employed to document the severity of a hearing loss are decibels hearing loss (dB HL). A person who can hear low decibel levels (-10 to 15 dB HL) is considered to have normal hearing. Someone having a slight hearing loss would not hear sounds until they reach 16 to 25 dB HL. Increasing in severity would be a mild loss (26 to 40 dB HL), a moderate loss (41 to 55 dB HL), a moderately severe loss (56 to 70 dB HL), a severe loss (71 to 90 dB HL), and a profound loss (91 + dB HL). All of the patients surveyed for this book had an average hearing level worse than 30 decibels in at least the better ear.
As a reference, a whisper at five feet is about 20 dB when measured using a slightly modified decibel scale (dBA) that ignores some low-frequency reverberant noise. A quiet office or library is 40 dBA, normal conversation is 60 dBA, and a flushed toilet 75–85 dBA. Any sound of 85 dB or greater is considered potentially damaging to the ear. This would include firearms, rock concerts, chainsaws, motorcycles, snowmobiles, and tractors.
Related to the bone-conduction test just described is a screening tool called the Rinne tuning-fork test. During this check the doctor strikes a metal tuning fork so that it rings, and then alternates between holding the tines of the tuning fork near the opening of the patient's ear and holding the base of the fork against the mastoid bone behind the ear. The vibrating tuning fork is heard normally through air conduction when near the ear canal. When held against the mastoid, the tuning fork transmits the sound vibrations directly to the inner ear through bone conduction. If the ear canal, eardrum, and ear bones work well in transmitting sound to the inner ear, the tuning fork will appear louder at the opening of the ear. If the tuning fork sounds louder when held against the mastoid bone, then a conductive hearing loss is indicated. This quick test from the physician's toolbox might seem archaic in the age of electronics. Even so, it can be up to 95 percent effective, and many doctors use it to screen for conductive losses and to confirm hearing test results.
Tympanometry
Aside from the standard hearing test battery, tympanometry is the next most likely test to have during an evaluation. As the name implies, tympanometry checks the tympanic membrane (eardrum). The patient sits quietly while the tester holds a special earplug in the opening of the ear canal. The person being tested hears a soft low-pitched hum and feels a slight pressure change in the ear canal. The machine attached to the earplug then measures how much sound is reflected back off the eardrum as the pressure is changed. When the pressure in the ear canal matches the pressure on the opposite side of the eardrum then the eardrum can move freely, transmitting sound farther into the ear. If, on the other hand, the pressure on one side is greater or less than on the other side, this stiffens the eardrum, reflecting sound back into the earplug. The result is a graph that should look much like a mountain peak. Tympanometry can show if there is a pressure imbalance in the ear, or a hole in the eardrum (even a pinpoint hole that is difficult to see), and it can help to confirm an observation of fluid or infection, since these can prevent the eardrum from moving. The test takes less than a minute for each ear and is painless.
(Continues...)
Excerpted from The Hearing-Loss Guide by John M. Burkey. Copyright © 2015 John M. Burkey. Excerpted by permission of Yale UNIVERSITY PRESS.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Table of Contents
Contents
Foreword, ix,Preface, xi,
Acknowledgments, xv,
Introduction, 1,
PART ONE: HEARING-LOSS BASICS,
1. The ABCs of Hearing Loss, 13,
2. Hearing Aids and Other Gadgets, 31,
3. Treatments for Hearing Loss, 49,
PART TWO: FIRST-HAND EXPERIENCE AND ADVICE,
4. Real-Life Consequences of Hearing Loss, 71,
5. Coping and Getting Help, 92,
6. The Hearing-Aid Experience, 112,
7. A Wish List, 136,
8. First-Hand Advice, 158,
9. Advice from Spouses or Significant Others, 183,
10. Themes and Parting Advice, 201,
Resources, 219,
Appendix: Hearing-Loss Questionnaires, 227,
Notes, 243,
Bibliography, 247,
Index, 255,