Causes of hearing loss (original) (raw)
With all of the extraordinary medical advances of the past few decades, one might reasonably expect that medical professionals would be able to enumerate the causes of deafness. It’s true that they can recite a long list of things that can cause deafness. But it’s also surprising how often they are unable to identify the specific cause of a specific person’s deafness.
Research is continuing in this area, and progress is being made. In the near future, today’s common story that no one knows why a particular person is deaf may be a thing of the past. In the meantime, here is some information on some of the causes of deafness.
There are basically two types of deafness. One is caused by problems with the sound reaching the inner ear. Since the sound travels there via conduction, this is called conductive hearing loss. It’s the far less common mechanism of hearing loss.
Much more common is sensorineural hearing loss. This is often called nerve deafness, but this is a misnomer, because the auditory nerve is almost never the cause. The problem is usually in the hair cells of the cochlea. One of the most devastating and mysterious forms of sensorineural hearing loss is sudden hearing loss or sudden deafness!
So what causes sensorineural hearing loss? Well, lots of things, many of which we can’t do much about. One big thing that we can control is noise. Noise is the enemy of hearing, and people are discovering that it doesn’t take as much noise as previously thought to cause temporary or permanent hearing loss. Here’s a bunch of information on Noise Induced Hearing Loss (NIHL).
Another surprisingly common cause of hearing loss is ototoxicity – the ability of drugs and medications to cause hearing loss.
Genetic factors have also been identified as causes of hearing loss.
Does aging cause hearing loss?
Do female hormonal changes cause hearing loss?
June 2000 – Scientists have recently discovered a chemical that not only is crucial to the hearing process, but might also have profound impact on unrelated aspects of science.
October 2004 – There’s been a long controversy regarding cell phone use causing cancer. Now there seems to be some evidence that long term cell phone use can cause acoustic neuromas – which cause deafness!
June 2005 – Do airbags cause hearing loss?
June 2005 – You know that noise can cause hearing loss. But did you know that the presence of carbon monoxide appears to increase the detrimental effect of noise on hearing?
January 2006 – We all know that exposure to loud noise can cause sensorineural hearing loss. Now there’s evidence that it can cause acoustic neuromas, as well! Here’s the story!
February 2006 – When hearing is lost in the brain
March 2006 – Tumor growth related to exposure to noise
March 2006 – A recent Mayo Clinic study contradicts a previous study indicating that arthritis increases the risk of hearing loss.
March 2006 – Scientists at the University of Michigan report new acoustic neuroma surgery that’s less damaging to hearing.
April 2006 – Can air bag deployment damage auditory function?
April 2006 – The presence of carbon monoxide seems to intensify hearing loss due to noise.
May 2006 – Drinking red wine may help prevent deafness
May 2006 –Inner Ear May Take Beating From High-Impact Aerobics
July 2006 – Nicotine Exposure During Fetal Development Leads To Hearing Problems
August 2006 – Protein Tied to Usher Syndrome May Be Hearing’s "Missing Link"
September 2006 – Children with Meningitis Should Have Early Hearing Test
November 2006 – Acoustic Shock Threatens Call Centre Staff
February 2007 – Car Airbags Will Cause Permanent Hearing Loss in 17 percent, Study Predicts
February 2007 – The Molecular Sound of Silence
June 2007 – Diabetics at Increased Risk of Hearing Loss
July 2007 – Smoking and Noise Result in Increased Hearing Loss
July 2007 – VHL Can Cause Sudden Hearing Loss
July 2007 – New Acoustic Neuroma Web Site
August 2007 – Psychogenic Hearing Loss: Detection Crucial to Proper Treatment
August 2007 – Auditory Neuropathy/Auditory Dys-synchrony
September 2007 – Diabetics at Increased Risk of Hearing Loss
October 2007 – Drinking may dampen hearing in the short term
October 2007 – Treating an acoustic neuroma
December 2007 – Occupational noise not linked to increased risk of acoustic neuroma
December 2007 – Here’s a Great Superficial Siderosis Site
December 2007 – Cholesterol Fine Tunes Hearing
January 2008 – Airbags and Ear Damage
January 2008 – OTC Eardrops May Cause Hearing Loss or Damage
January 2008 – Deafness and Seizures Result When Mysterious Protein Deleted in Mice
March 2008 – Common Virus Causes Hearing Loss in Fetus
March 2008 – Treatment of rare condition will cause woman to go deaf
March 2008 – ‘Have Another Beer.’ ‘I SAID HAVE ANOTHER BEER!’
April 2008 – Top 5 Ways to Protect Your Hearing
June 2008 – Acoustic neuromas: Wait and see or surgery
June 2008 – Child’s kiss deafens Hicksville mom
June 2008 – Why the obese and smokers risk deafness
June 2008 – Hearing Loss Is Common in People with Diabetes
~~~~~~~~~~~~~~~~~
When hearing is lost in the brain
February 2006
Age-related hearing loss is not just a case of the ears losing their capability. The ability of the brain to process sound is weakened as well. Modern digital hearing aids with directional microphones may solve some of these problems. The ears are still crucial for hearing, but preliminary studies in mice indicate that a decrease in certain processes in the brain may make it harder to filter out unimportant sounds. "Traditionally, scientists studying hearing problems started looking at the ear. But we are finding patients with normal ears who still have trouble understanding a conversation. There are many people who have good inner ears who just don’t hear well. That’s because their brains are aging," said Dr. Robert D. Frisina of the University of Rochester Medical Center. Full Story
~~~~~~~~~~~~~~~~~
Tumor growth related to exposure to noise
March 2006
The eighth cranial nerve has two branches, one that is responsible for balance and one that is responsible for hearing sensitivity. An acoustic neuroma is a non-cancerous tumor that grows on the eighth cranial nerve. The tumor typically grows very slowly and affects only one ear. Symptoms are not generally noticed until the tumor is large enough to puts pressure on nerves, causing the symptoms, including hearing loss, tinnitus, and facial weakness or numbness on the affected side, as well as dizziness or balance problems. Full Story
~~~~~~~~~~~~~~~~~
Dim view of aging linked to hearing loss
March 2006
Older adults who harbor negative stereotypes about aging may have a more rapid decline in their hearing, a new study suggests. Researchers at Yale University found that among older men and women, between 70 and 96 years old, those who held to the stereotypes of older adults as "frail" and "senile" showed a greater decline in hearing over the next three years. The link was independent of a number of factors in hearing loss, including age, physical health and depression. The effect was seen even in study participants who had "perfect scores" on hearing tests at the study’s start, lead study author Becca R. Levy told Reuters Health. Full Story
~~~~~~~~~~~~~~~~~
Can air bag deployment damage auditory function?
April 2006
On Monday, June 6, 2005, Lisa wrote the following on the Hearing Loss Web Forum under the topic of "Air Bags Ruined My Hearing:"
“Last week I was involved in what should have been a minor car accident. I wasn’t paying attention and ‘gently’ hit the car in front of me stopped for a light. What happened next was terrifying. The inside of the car seemed to explode in a deafening roar. I had an unimaginable pain in both ears and considerable bleeding from my ear canals. I also had a very loud ringing and was virtually deaf.” Full Story
~~~~~~~~~~~~~~~~~
Drinking red wine may help prevent deafness
Age-related deafness, and hearing loss caused by loud noise, may be reduced by the antioxidants in red wine, green tea and aspirin, it was claimed yesterday. The compounds they contain could help protect the delicate hairs of the inner ear that are vital to hearing, new research suggests. Destructive chemical agents called oxygen-free radicals, produced by normal cellular processes and in response to loud noise and exposure to powerful antibiotics, can damage the hairs. But antioxidants such as resveratrol, found in red wine and green tea, and salicylate, the active ingredient in aspirin, should be able to neutralise them. Full Story
~~~~~~~~~~~~~~~~~
Inner Ear May Take Beating From High-Impact Aerobics
May 2006
PEOPLE who engage in demanding physical activities might expect to suffer occasional injuries to the body parts directly involved. But few devotees of high-impact aerobics are likely to guess that their jumping and bouncing to music could damage their inner ears, causing symptoms like persistent vertigo, dizziness, imbalance, motion sickness, ringing or fullness in the ear and high-frequency hearing loss. Yet just such a syndrome has been identified in a group of 30 otherwise healthy women in the Westchester County area of New York who regularly do high-impact aerobics, which involves a lot of bouncing up and down, often with both feet off the ground at once. Full Story
~~~~~~~~~~~~~~~~~
Acoustic Shock Threatens Call Centre Staff
November 2006
Acoustic shocks are defined as "any temporary or permanent disturbance of the functioning of the ear, or of the nervous system, which may be caused to the user of a telephone earphone by a sudden sharp rise in the acoustic pressure produced by it". The sound could be a whistle, a bleep – or any unexpected noise. . . . Dr Mark Downs, executive director of technology and enterprise for the Royal National Institute for the Deaf, said: "Acoustic shock is not the same as noise-induced hearing loss and is believed to occur at sound pressure levels below those which present an immediate risk to hearing damage. "It is still a relatively un-researched condition and RNID welcomes public debate on the issue." Full Story
~~~~~~~~~~~~~~~~~
The Molecular Sound of Silence
February 2007
"(Hearing) is a very complicated process where lots of things can go wrong," Wong said. "What we have done is study one of those things." That thing is a mutation in a type of protein molecule called espin, a "binder" or "linker" protein common in nature, particularly in sensing cells. In the ear’s hair cells, espin links rod-like protein molecules called filamentous actin, or F-actin, into bundles, Wong said. The problem occurs when a mutated form of espin – which needs binding sites on both sides, kind of like double-stick tape, to function properly – fails to secure the F-actin bundles tightly. Full Story
~~~~~~~~~~~~~~~~~
Diabetics at Increased Risk of Hearing Loss
June 2007
Diabetics have twice the risk of developing hearing loss as are nondiabetics, researchers reported here at the American Diabetes Association 67th Scientific Sessions (ADA). . . . . "The pathologic changes that accompany diabetes could plausibly affect the vasculature or the neural system of the inner ear, resulting in sensorineural hearing impairment," Dr. Cowie explained in a presentation on June 24th. . . . . After adjusting for age, 31.6% of self-reported diabetics had hearing impairment at the lower frequency range versus 14.5% of the nondiabetics subjects. The figures were 56.8% and 35.8% for the two groups, respectively, at the higher frequency range. Full Story
~~~~~~~~~~~~~~~~~
VHL Can Cause Sudden Hearing Loss
July 2007
Patients with the genetic disorder von Hippel-Lindau (VHL) disease may suddenly experience hearing loss because of a tumor-associated hemorrhage in the inner ear, according to a study in the July 4 issue of the Journal of the American Medical Assocation (JAMA). Endolymphatic sac tumors (ELSTs; tumors of the inner ear) occur sporadically but may be associated with von Hippel-Lindau disease (a genetic disease characterized by the development of blood vessel tumors in the retina of the eye and in the brain; lesions and cysts can also develop in other parts of the body). ELSTs are associated with significant dysfunction of hearing and balance, including sudden irreversible hearing loss. The mechanisms and appropriate treatments for this disorder are not well understood. Full Story
~~~~~~~~~~~~~~~~~
New Acoustic Neuroma Web Site
Editor: Acoustic Neuromas are fairly common causes of hearing loss, but most people know very little about them. Here’s a bit of information on acoustic neuromas and a new website that offers additional help.
~~~~~~~~~~~~~~~~~
July 2007
The Acoustic Neuroma Association (ANA) has launched a new medical Web site listing http://www.anausa.org/index.html for newly diagnosed and current acoustic neuroma patients. ANA is a non-profit organization with the mission to inform, educate and provide national and local support networks for those affected by acoustic neuromas, and to be an essential resource for health care professionals who treat the condition. Founded by Virginia Fickel Her, a patient, the AHA has been a source of information and support for acoustic neuroma patients for over 25 years, and oversees over 50 local support groups around the country.
An acoustic neuroma (sometimes termed a vestibular schwannoma) is a benign brain tumor on the eighth cranial nerve, which leads from the brain to the inner ear. Typical symptoms include hearing loss, balance issues, tinnitus and a feeling of fullness in the ear. The most common forms of treatment are surgery, radiation or "watch and wait."
According to Judy Vitucci, executive director of ANA, "The new medical Web site listing is designed to provide up-to-date information regarding the most important question for a new patient — where do I find a qualified physician?" She added, "Although this is a rare type of tumor, recent studies show that acoustic neuroma diagnoses are increasing, and most patients are between the ages of 30 and 60."
The new Web site will provide patients with a tool to help them find qualified medical professionals across the country. The site also provides information on the various types of treatment. Additionally, users can fill in the "contact us" information, and ANA will send them a packet of information with referrals of former patients who can provide support. Visit http://www.anausa.org/index.html for more information.
~~~~~~~~~~~~~~~~~
Psychogenic Hearing Loss: Detection Crucial to Proper Treatment
August 2007
Psychogenic hearing loss, also known as pseudohypacusis, non-organic or functional, originates in the mind of an individual and is thereby psychological rather than physiological in nature. The loss may be classified either as intentional and based on underlying motives such as monetary compensation or sympathy needs or unintentional and based on underlying stress or anxiety. The detection of psychogenic hearing loss has long been the concern of audiologists. Full Story
~~~~~~~~~~~~~~~~~
Auditory Neuropathy/Auditory Dys-synchrony
August 2007
A little more than a decade ago, researchers led by Arnold Starr of the Department of Neurology at the University of California, described hearing impairments in ten young patients that were compatible with a disorder of the auditory portion of the 8th cranial nerve.1 The disorder was and continues to be characterized by normal cochlear outer hair cell function, absent or abnormal auditory brainstem responses (ABR), and unexpectedly poor speech discrimination. Later, eight of the patients developed evidence for a peripheral neuropathy, and the researchers suggested that “this type of hearing impairment is due to a disorder of auditory nerve function and may have, as one of its causes, a neuropathy of the auditory nerve, occurring either in isolation or as part of a generalized neuropathic process.” The use of the term “auditory neuropathy” to designate this particular profile of hearing disorders remains debatable, and doubts remain whether the condition represents a true auditory nerve neuropathy. The loss of neural synchrony of auditory nerve fibers leads to the view that the term “auditory dys-synchrony” may provide “a more comprehensive view of auditory neuropathy that connects logically to viable management options. Full Story
~~~~~~~~~~~~~~~~~
Diabetics at Increased Risk of Hearing Loss
September 2007
Diabetics have twice the risk of developing hearing loss as are nondiabetics.
Catherine C. Cowie, PhD, director, diabetes epidemiology program, National Institute of Diabetes and Digestive and Kidney Diseases, reported data in 5,140 individuals aged 20 to 69 years who underwent audiometric testing from 1999 through 2004 as part of the National Health and Nutrition Examination Survey (NHANES). "The pathologic changes that accompany diabetes could plausibly affect the vasculature or the neural system of the inner ear, resulting in sensorineural hearing impairment," Dr. Cowie explained in a presentation. In the NHANES trial, pure tone thresholds over lower frequency were obtained for each ear at 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz using a calibrated audiometer in a soundproof booth. A pure tone average exceeding 25 decibels over a given frequency range in both ears indicated hearing impairment. Full Story
~~~~~~~~~~~~~~~~~
Drinking may dampen hearing in the short term
October 2007
If you have a hard time hearing conversation at a bar, it may not be because of the noise, a study suggests. Alcohol, UK researchers found, seems to temporarily drain a person’s hearing — particularly when it comes to discerning the sounds of conversation. In a study of 30 healthy volunteers, they found that as participants drank, their hearing became less acute. Lower-frequency hearing, which is necessary for discerning speech, suffered the most, the researchers report in the online journal BMC Ear, Nose and Throat Disorders. Full Story
~~~~~~~~~~~~~~~~~
Treating an acoustic neuroma
October 2007
DEAR MAYO CLINIC: I’m 59 and have been diagnosed with an acoustic neuroma. I have been to a surgeon and his explanation of the surgical procedure has me so frightened that I have chosen to do nothing. I have many bouts of dizziness and some hearing loss. Could you better explain the surgery as well as the benefit or drawbacks of radiation? Full Story
~~~~~~~~~~~~~~~~~
Occupational noise not linked to increased risk of acoustic neuroma
December 2007
Contradicting some prior reports, new study results do not demonstrate an increased risk of acoustic neuroma related to occupational noise exposure. "A small number of prior epidemiologic studies of occupational noise exposure based on self-report have suggested an association with acoustic neuroma," Dr. Colin Edwards, of Ohio State University, Columbus, and colleagues write in the December 1st issue of the American Journal of Epidemiology. The researchers examined the putative association in a register-based case-control study. A total of 793 acoustic neuroma cases were identified between 1987 and 1999 from the Swedish Cancer Registry, and these were matched to 101,756 control subjects randomly selected from the Swedish Population Registry. Full Story
~~~~~~~~~~~~~~~~~
Here’s a Great Superficial Siderosis Site
Editor: I met Dave Hill online several years ago when he posted to the Hearing Loss Web Forum. Dave has superficial siderosis (SS), and he was interested in helping others who also had that condition. So he developed a website and had soon gathered a community of SS survivors. Here’s Dave with a bit about SS and his site.
~~~~~~~~~~~~~~~~~
www.superficialsiderosis.org.nz is a site written by a Superficial Siderosis survivor, Dave Hill of New Zealand, for fellow survivors. It has been praised by published Neurologists for its ability to describe the medical condition in plain understandable English.
Superficial Siderosis is a rare condition which in almost every case reduces the patient’s hearing to zero, produces quite unstable balance and coordination, vision complications, plus up to 15 – 20 other associated sideline effects depending on the recipient. Many patients are confined to a wheelchair for mobility, some bedridden.
As a result of Central Nervous System bleeding which congregates around the brain’s cerebellum, over a varying period of time the blood forms into an iron salt casing, stopping brain movement in both directions. There is nothing currently known to man to eliminate the problem.
~~~~~~~~~~~~~~~~~
Airbags and Ear Damage
January 2008
A 2007 study predicts that airbag deployment in automobile accidents leads to permanent hearing loss in 17 percent of those exposed.1 The prediction is based upon the Auditory Hazard Assessment Algorithm for the Human (AHAAH), a mathematical computer model of the ear which, according to the author of the study, is "designed to reproduce the ear’s physiological response to virtually any intense sounds and to predict hazard from calculated displacements in the inner ear." These surprisingly high estimates of permanent sensorineural hearing loss, based on a computer model with 95 percent accuracy, bring to the forefront again the dangers of airbag deployment to the ear in the more than 6 million automobile accidents per year in the United States alone. Even minor bumper-benders in slow speed collisions, representing little or no danger of injury to occupants who are safely buckled up, can cause the airbag to inflate. Rushing toward startled drivers and passengers at speeds of 180 mph and with noise levels of 170 dB or more, airbags can cause many other otologic injuries in addition to permanent hearing loss. Full Story
~~~~~~~~~~~~~~~~~
Common Virus Causes Hearing Loss in Fetus
March 2008
A virus that infects up to 85 percent of adults in the U.S. by age 40 is also the virus most frequently transmitted to a child before birth. For most adults, the virus goes unnoticed, but for babies it can be life-changing. Now, thanks to a $1 million grant, Carolinas Medical Center is studying the virus and its relationship to hearing loss in newborns. By all accounts, six-month-old Sydney is healthy, but thanks to an infection called congenital Cytomegalovirus, or CMV, silence could be what Sydney hears down the road. The CMV virus is carried by the mother and spreads to the child during pregnancy. "And if a baby develops that infection before they are born then they can be effected with hearing loss developmental delay, with all sorts of complications," explained pediatrician Dr. Amina Ahmed of Carolinas Medical Center. Full Story
~~~~~~~~~~~~~~~~~
Treatment of rare condition will cause woman to go deaf
March 2008
Researchers may be coming close to the cure for Neurofibromatosis (NF), a disease that is about to drastically change a Muskegon woman’s life forever. It’s a rare condition but it’s thousands across the country have it, affecting each patient differently. The disease is life changing and can be fatal. Those who suffer get tumors that don’t stop growing. "Patients who have neurofibromatosis can develop these tumors. They’re not cancerous tumors, they don’t spread through the body and things like that, but they do grow in one spot and cause problems," said Dr. Al Cornelius of Spectrum Health, an NF researcher. [. . . ] Cornelius is preparing for a clinical trial that will take place in Grand Rapids at the DeVos Children’s Hospital. He’s hoping that his findings will provide answers and solutions for the 100,000 Americans who suffer from the condition and says so far results are looking promising. [. . . ] Jessica’s surgery is next month. It may be the most crucial of them all because when she comes out she’ll be changed forever. "I’m getting ready for a surgery on the right side to remove the other acoustic neuroma and it will result in me being deaf," she said. Full Story
~~~~~~~~~~~~~~~~~
‘Have Another Beer.’ ‘I SAID HAVE ANOTHER BEER!’
March 2008
Ever notice that when you’re at a social gathering, private home or down at the neighborhood watering hole, and you’re designated the designated driver (Yes, I’ll have a cranberry spritzer. I have to drive this crew home later.), just how loud everyone talks. And as the libations flow freely, the sound just gets louder and louder and LOUDER! Well, you might think that it’s the tequila shooters loosening up the party-goers that brings that volume to such high levels – and that’s part of it. But it’s not just high spirits that pumps up the volume. Drinking alcohol lessens your ability to hear. "What’d ya say?" True story. British researchers at the University College of London Hospitals, lead by Tahwinder Upile, studied a group of 30 healthy adults, tested their hearing levels sober and as they consumed alcohol and discovered that as the subjects drank, their hearing became "less acute." Full Story
~~~~~~~~~~~~~~~~~
Acoustic neuromas: Wait and see or surgery
June 2008
An acoustic neuroma (vestibular schwannoma) is a benign, slow growing, well encapsulated tumor arising from the sheath surrounding the 8th cranial nerve. The 8th cranial nerve, the acoustic nerve, is comprised of two nerve branches: one controls balance (vestibular) and the other hearing (auditory). (See Cranial nerves .) Most acoustic neuromas start within the internal auditory canal and extend into the cerebellopontine angle (CPA), pressing on the brain stem. . . . The earliest symptom of an acoustic neuroma is gradual hearing loss due to the progressive growth of the tumor in the internal ear canal. Hearing loss is usually characterized by a distortion in perception and acuity of sound. Patients present with tinnitus (a roaring, buzzing, or hissing sound) that may be intermittent or constant. As the tumor grows, there may be balance disturbances, vertigo with sudden changes in position, headaches, and facial or ear pain. These symptoms are the result of the compression and stretching of cranial nerves, although the brain compensates for the unsteadiness, so symptoms of balance disturbance may be ignored. Constant or intermittent facial tingling or numbness may be another sign related to nerve compression. Full Story
~~~~~~~~~~~~~~~~~
Child’s kiss deafens Hicksville mom
June 2008
This is a story about a kiss – an expression of love so potent from a little girl – that it caused her mother not only to lose her hearing after a buss on the ear, but to be thrust into the pages of medical history. Yet it wasn’t the sound of the smackaroo that damaged the hearing of Hicksville homemaker Gail Schwartzman, but a suction force that displaced the woman’s eardrum, paralyzed a tiny trio of bones and left residual sounds in her head. Schwartzman’s case will be the subject of a medical journal report within the coming weeks, outlining for the first time what the author calls "the kiss of deaf." Schwartzman describes the kiss as physically painful but says it has left a deeper emotional scar on her daughter. Even as she recounted details of the buss planted two years ago, the child, now 6, broke into tears, apologizing to her mom. Schwartzman requested that her daughter’s name not be published. Full Story
~~~~~~~~~~~~~~~~
Why the obese and smokers risk deafness
June 2008
Perhaps unsurprisingly, noise exposure, known to destroy the sound-transducing hair cells in the inner ear, was the biggest risk. More surprising is the apparent effect of smoking and overeating. These factors have been suspected as potential causes of deafness, but it has been hard to separate them from the effects of cardiovascular diseases that are also frequently suffered by people who smoke and overeat. This study has been able to do just that. Full Story