Hearing
Do you hear what I hear?
Cochlear Implants
Noise, Ears & Hearing Protection
Do you hear what I hear?
Andrew R. Spector, MD
Do you find that you have been turning up the volume louder on your television and asking people to repeat themselves? Do you avoid talking on the phone or going out to restaurants and other crowded places because of difficulty understanding conversations?
Do you ever hear a ringing, whistle or humming that other people do not seem to hear or get asked why you are talking so loudly? Do you ever strain to hear or have trouble telling from what direction a sound is coming? If any of this sounds familiar and you find yourself nodding your head ‘yes’ while reading this you, like 22 million other adults, might have hearing loss.
Without adequate hearing, it may be difficult to enjoy music, attend theater performances or movies. An individual’s safety may also be affected if unable to hear a doorbell, fire alarm, or car horn.
Hearing loss is well known to effect social and emotional well-being and people who suffer from it often report depression and withdraw from social activities. This is very unfortunate as hearing loss is so simple to diagnose and treat.
Around 30 to 35% of Americans between the age of 65 and 75 and nearly 50% over the age of 75 have treatable hearing loss. Not only are the sheer numbers of those over the age of 65 increasing, but also the percentage of this population in proportion to the whole country. When the ‘Baby Boom’ turns 65 in 2011, those numbers will continue to increase until 2030 when the segment of the population over 65 will have grown 20%. Think about it, nearly 10% of the population will have hearing loss but only
one out of every five does something about it. Furthermore, very few physicians screen for hearing loss in the elderly even though it ranks behind only hypertension and arthritis amongst chronic conditions affecting senior citizens.
Age-related hearing loss, also called presbycusis, is the most common cause of hearing loss in this age range and is usually rehabilitated with hearing aids. Age-related hearing loss is typically caused by gradual changes in the inner ear and hearing nerve. These changes develop so slowly that many people do not realize that their hearing is even diminished. Instead, they may complain that others are mumbling or speaking less clearly making conversations difficult to understand particularly in crowds. Some sounds may actually be too loud and tinnitus, or ringing in the ears, is often present.
There are many other potential medical causes of hearing loss that must be ruled-out by a physician who specializes in disorders of the ear – an Otolaryngologist (or ear, nose and throat doctor). Other medical problems, including heart disease, diabetes and medication side effects, can accelerate hearing loss. Also, changes from ear infections, holes in the eardrum and earwax impactions can cause hearing loss – medical problems that require a physician to diagnose and implement treatment. Hearing loss is relatively simple to diagnose. An Audiologist will perform an audiogram (hearing test) to determine the presence and severity of hearing loss while an Otolaryngologist will rule out a medical cause of hearing loss. The FDA (Food and Drug Administration) has determined that it is in your best health interest to have a medical examination by a licensed physician preferably one that specializes in ear diseases before buying a hearing aid. Once hearing loss has been diagnosed, there are several options to treat it. Unfortunately no means of reversing age-related hearing loss have been discovered, although scientists are exploring restoration of inner ear function. Instead, treatment is aimed at compensating for what has been lost. Encouraging people to speak clearly and slowly while directly facing you during a conversation may prove helpful. There are also assistive living devices that can send a soundwave from the television to a pair of headphones like a radio or simply amplifiers built-in to the telephone. In some cases of very severe hearing loss, cochlear implants may be required to improve hearing loss.
The most reliable means to rehabilitate hearing loss is with hearing aids. If properly fitted in people who are good candidates for amplification, hearing aids can help to restore hearing.
Technology for hearing aids is constantly improving so that they can be specifically tailored to each individual’s unique pattern of hearing loss. Digital programming can help to selectively amplify only the frequencies where hearing loss exists while limiting the maximum volume presented to the ear to prevent discomfort. Some people require hearing aids for both ears and some in just one. There are multiple sizes and styles of hearing aids that each have advantages depending on the severity of the hearing loss and each individual’s ability to care for the hearing aid. Well-trained Audiologists and Otolaryngologists can provide appropriate counseling as to whether a person is a candidate for hearing aid amplification, benefits and limitations of amplification, and which device best suits each person.
For a hearing test, ear evaluation and recommendations on improving your hearing, contact Ear, Nose and Throat Specialists of Southern New Hampshire at 622-3623 or explore the website: entspecialistsnh.com.
Cochlear Implants
What Is a Cochlear Implant?
Insight into an implantable device to help you hear A cochlear implant is an electronic device that restores partial hearing to the deaf. It is surgically implanted in the inner ear and activated by a device worn outside the ear. Unlike a hearing aid, it does not make sound louder or clearer. Instead, the device bypasses damaged parts of the auditory system and directly stimulates the nerve of hearing, allowing individuals who are profoundly hearing impaired to receive sound.
What is normal hearing?
Your ear consists of three parts that play a vital role in hearing—the external ear, middle ear, and inner ear.
Conductive hearing: Sound travels along the ear canal of the external ear causing the ear drum to vibrate. Three small bones of the middle ear conduct this vibration from the ear drum to the cochlea (auditory chamber) of the inner ear.
Sensorineural hearing: When the three small bones move, they start waves of fluid in the cochlea, and these waves stimulate more than 16,000 delicate hearing cells (hair cells). As these hair cells move, they generate an electrical current in the auditory nerve. It travels through inner-connections to the brain area, which recognizes it as a sound.
How is hearing impaired?
If you have a disease or obstruction in your external or middle ear, your conductive hearing may be impaired. Medical or surgical treatment can probably correct this.
An inner ear problem, however, can result in a sensorineural impairment or nerve deafness. In most cases, the hair cells are damaged and do not function. Although many auditory nerve fibers may be intact and can transmit electrical impulses to the brain, these nerve fibers are unresponsive because of hair cell damage. Since severe sensorineural hearing loss cannot be corrected with medicine, it can be treated only with a cochlear implant.
How do cochlear implants work?
Cochlear implants bypass damaged hair cells and convert speech and environmental sounds into electrical signals and send these signals to the hearing nerve.
The implant consists of a small electronic device, which is surgically implanted under the skin behind the ear and an external speech processor, which is usually worn on a belt or in a pocket. A microphone is also worn outside the body as a headpiece behind the ear to capture incoming sound. The speech processor translates the sound into distinctive electrical signals. These ‘codes’ travel up a thin cable to the headpiece and are transmitted across the skin via radio waves to the implanted electrodes in the cochlea. The electrodes signals stimulate the auditory nerve fibers to send information to the brain where it is interpreted as meaningful sound.
Who can benefit from an implant?
Implants are designed only for individuals who attain almost no benefit from a hearing aid. They must be two years or age or older (unless childhood meningitis is responsible for deafness).
Otolaryngologists (ear, nose, and throat specialists) perform implant surgery, though not all of them do this procedure. Your general practitioner can refer you to an implant clinic for an evaluation. The evaluation will be done by an implant team (an otolaryngologist, audiologist, nurse, and others) that will give you a series of tests:
- Ear (otologic) evaluation: The otolaryngologist examines the middle and inner ear to ensure that no active infection or other abnormality precludes the implant surgery.
- Hearing (audiologic) evaluation: The audiologist performs an extensive series of hearing tests to find out how much you can hear with and without a hearing aid.
- X-ray (radiographic) evaluation: Special X-rays are taken, usually computerized tomography (CT) or magnetic resonance imaging (MRI) scans, to evaluate your inner ear bone.
- Psychological evaluation: Some patients may need a psychological evaluation to learn if they can cope with the implant.
- Physical examination: Your otolaryngologist also gives a physical examination to identify any potential problems with the general anesthesia needed for the implant procedure.
When is surgery necessary?
Implant surgery is performed under general anesthesia and lasts from two to three hours. An incision is made behind the ear to open the mastoid bone leading to the middle ear. The procedure may be done as an outpatient procedure, or may require a stay in the hospital, overnight or for several days, depending on the device used and the anatomy of the inner ear.
Training, Expectation, and Cost
Is there care and training after the surgery?
About one month after surgery, your team places the signal processor, microphone, and implant transmitter outside your ear and adjusts them. They teach you how to look after the system and how to listen to sound through the implant. Some implants take longer to fit and require more training. Your team will probably ask you to come back to the clinic for regular checkups and readjustment of the speech processor as needed.
What can I expect from an implant?
Cochlear implants do not restore normal hearing, and benefits vary from one individual to another. Most users find that cochlear implants help them communicate better through improved lip-reading, and over half are able to discriminate speech without the use of visual cues. There are many factors that contribute to the degree of benefit a user receives from a cochlear implant, including:
— the length of time a person has been deaf
— the number of surviving auditory nerve fibers, and
— a patient’s motivation to learn to hear.
Your team will explain what you can reasonably expect. Before deciding whether your implant is working well, you need to understand clearly how much time you must commit. A few patients do not benefit from implants.
How are new implant devices approved?
The Food and Drug Administration (FDA) regulates cochlear implant devices for both adults and children and approves them only after thorough clinical investigation.
Be sure to ask your otolaryngologists for written information, including brochures provided by the implant manufacturers. You need to be fully informed about the benefits and risks of cochlear implants, including the device’s safety, reliability, and effectiveness. Also, be sure to inquire about follow up checkups and whether your insurance company pays for the procedure.
How much does an implant cost?
More expensive than a hearing aid, the total cost of a cochlear implant including evaluation, surgery, the device, and rehabilitation is around $30,000. Most insurance companies provide benefits that cover the cost. (This is true whether or not the device has received FDA clearance or is still in trial.)
Insight into Noise, Ears & Hearing Protection
One in 10 Americans has a hearing loss that affects his or her ability to understand normal speech. Excessive noise exposure is the most common cause of hearing loss.
Can Noise Really Hurt My Ears?
Yes, noise can be dangerous. If it is loud enough and lasts long enough, it can damage your hearing. The damage caused by noise, called sensorineural hearing loss or nerve deafness, can be caused by several factors other than noise, but noise-induced hearing loss is different in one important way––it can be reduced or prevented altogether.
Can I “Toughen Up” My Ears?
No. If you think you have grown used to a loud noise, it probably has damaged your ears, and there is no treatment––no medicine, no surgery, not even a hearing aid––that completely restores your hearing once it is damaged by noise.
How Does the Ear Work?
The ear has three main parts: the outer, middle, and inner ear. The outer ear (the part you can see) opens into the ear canal. The eardrum separates the ear canal from the middle ear. Small bones in the middle ear help transfer sound to the inner ear. The inner ear contains the auditory (hearing) nerve, which leads to the brain.
Any source of sound sends vibrations or sound waves into the air. These funnel through the ear opening, down the ear canal, and strike your eardrum, causing it to vibrate. The vibrations are passed to the small bones of the middle ear, which transmit them to the hearing nerve in the inner ear. Here, the vibrations become nerve impulses and go directly to the brain, which interprets the impulses as sound: music, a slamming door, a voice, etc.
When noise is too loud, it begins to kill the nerve endings in the inner ear. As the exposure time to loud noise increases, more and more nerve endings are destroyed. As the number of nerve endings decreases, so does your hearing. There is no way to restore life to dead nerve endings; the damage is permanent.
How Can I Tell If a Noise Is Dangerous?
People differ in their sensitivity to noise. As a general rule, noise may damage your hearing if you have to shout over background noise to make yourself heard, the noise hurts your ears, it makes your ears ring, or you have difficulty hearing for several hours after exposure to the noise.
Sound can be measured scientifically in two ways. Intensity, or loudness of sound, is measured in decibels. Pitch is measured in frequency of sound vibrations per second. A low pitch, such as a deep voice or a tuba, makes fewer vibrations per second than a high voice or violin.
What Does Frequency of Sound Vibration Have to Do with Hearing Loss?
Frequency is measured in cycles per second, or Hertz (Hz). The higher the pitch of the sound, the higher the frequency.
Young children, who generally have the best hearing, can often distinguish sounds from about 20 Hz, such as the lowest note on a large pipe organ, to 20,000 Hz, such as the high shrill of a dog whistle that many people are unable to hear.
Human speech, which ranges from 300 to 4,000 Hz, sounds louder to most people than noises at very high or very low frequencies. When hearing impairment begins, the high frequencies are usually lost first, which is why people with hearing loss often have difficulty hearing the high pitched voices of women and children. Loss of high frequency hearing also can distort sound, so that speech is difficult to understand even though it can be heard. People with hearing loss often have difficulty detecting differences between certain words that sound alike, especially words that contain S, F, SH, CH, H, or soft C sounds, because the sound of these consonants is in a much higher frequency range than vowels and other consonants.
What about Decibels?
Intensity of sound is measured in decibels (dB). The scale runs from the faintest sound the human ear can detect, which is labeled 0 dB, to over 180 dB, the noise at a rocket pad during launch.
Decibels are measured logarithmically. This means that as decibel intensity increases by units of 10, each increase is 10 times the lower figure. Thus, 20 decibels is 10 times the intensity of 10 decibels, and 30 decibels is 100 times as intense as 10 decibels.
How High Can the Decibels Go without Affecting My Hearing?
Many experts agree that continual exposure to more than 85 decibels is dangerous.
Does the Length of Time I Hear a Noise Have Anything to Do with the Danger to My Hearing?
It certainly does. The longer you are exposed to a loud noise, the more damaging it may be. Also, the closer you are to the source of intense noise, the more damaging it is. Every gunshot produces a noise that could damage the ears of anyone in close hearing range. Large bore guns and artillery are the worse because they are the loudest. But even cap guns and firecrackers can damage your hearing if the explosion is close to your ear. Anyone who uses firearms without some form of ear protection risks hearing loss. Recent studies show an alarming increase in hearing loss in youngsters. Evidence suggests that loud rock music along with increased use of portable radios with earphones may be responsible for this phenomenon.
| Approx. Decibel Level | Example |
| 0 | Faintest sound heard by human ear. |
| 30 | Whisper, quiet library. |
| 60 | Normal conversation, sewing machine, typewriter. |
| 90 | Lawnmower, shop tools, truck traffic; 8 hours per day is the maximum exposure to protect 90% of people. |
| 100 | Chainsaw, pneumatic drill, snowmobile; 2 hours per day is the maximum exposure without protection. |
| 115 | Sandblasting, loud rock concert, auto horn; 15 minutes per day is the maximum exposure without protection. |
| 140 | Gun muzzle blast, jet engine; noise causes pain and even brief exposure injures unprotected ears. Maximum allowed noise with hearing protectors. |
Can Noise Affect More Than My Hearing?
A ringing in the ears, called tinnitus, commonly occurs after noise exposure, and it often becomes permanent. Some people react to loud noise with anxiety and irritability, an increase in pulse rate and blood pressure, or an increase in stomach acid. Very loud noise can reduce efficiency in performing difficult tasks by diverting attention from the job.
Who Should Wear Hearing Projectors?
If you must work in an excessively noisy environment, you should wear protectors. You should also wear them when using power tools, noisy yard equipment, or firearms, or riding a motorcycle or snowmobile.
What Are the Laws for on-the-Job Exposure?
Noise, Ears & Hearing Protection
Habitual exposure to noise above 85 dB will cause a gradual hearing loss in a significant number of individuals, and louder noises will accelerate this damage. For unprotected ears, the allowed exposure time decreases by one-half for each 5 dB increase in the average noise level. For instance, exposure is limited to 8 hours at 90 dB, 4 hours at 95 dB, and 2 hours at 100 dB.
The highest permissible noise exposure for the unprotected ear is 115 dB for 15 minutes/day. Any noise above 140 dB is not permitted.
The Occupational Safety and Health Administration, in its Hearing Conservation Amendment of 1983, requires hearing conservation programs in noisy work places. This includes a yearly hearing test for the approximately five million workers exposed to an average of 85 dB or more of noise during an 8-hour work day.
Ideally, noisy machinery and work places should be engineered to be more quiet or the worker’s time in the noise should be reduced; however, the cost of these actions is often prohibitive. As an alternative, individual hearing protectors are required when noise averages more than 90 dB during an 8-hour day.
When noise measurements indicate that hearing protectors are needed, the employer must offer at least one type of earplug and one type of earmuff without cost to employees. If the yearly hearing tests reveal hearing loss of 10 dB or more in higher pitches in either ear, the worker must be informed and must wear hearing protectors when noise averages more than 85 dB for an 8-hour day.
Larger losses of hearing and/or the possibility of ear disease should result in referral to an ear, nose and throat physician (otolaryngologist).
What Are Hearing Protectors? How Effective Are They?
Hearing protection devices decrease the intensity of sound that reaches the eardrum. They come in two forms: earplugs and earmuffs.
Earplugs are small inserts that fit into the outer ear canal. They must be snugly sealed so the entire circumference of the ear canal is blocked. An improperly fitted, dirty or worn-out plug may not seal and can irritate the ear canal. They are available in a variety of shapes and sizes to fit individual ear canals and can be custom made. For people who have trouble keeping them in their ears, they can be fitted to a headband.
Earmuffs fit over the entire outer ear to form an air seal so the entire circumference of the ear canal is blocked, and they are held in place by an adjustable band. Earmuffs will not seal around eyeglasses or long hair, and the adjustable headband tension must be sufficient to hold earmuffs firmly around the ear.
Properly fitted earplugs or muffs reduce noise 15 to 30 dB. The better earplugs and muffs are approximately equal in sound reductions, although earplugs are better for low frequency noise and earmuffs for high frequency noise.
