Hey, can’t you turn that down?" our parents used to yell at us. "I can’t hear myself think." But we knew better — rock and roll was supposed to be loud. In fact, if there’s one crucial emblem of American youth culture it’s loud music, very loud music. Rock and roll in the‘60s, disco and heavy metal in the‘70s, rap and hip-hop in the‘80s and‘90s — no matter how the styles have changed, the common denominator is that they’re supposed to be loud. You were not getting the full effect unless you could walk into the arena and feel the bass line thumping in your viscera. Better yet, you could push your way to the front, stand directly in front of those towering guitar amps, and get blown away by the power chords. One of the champions of loud and louder rock and roll was Pete Townshend of The Who, who liked to climax his show with a screaming explosion of feedback and amplified cacophony as he and the other members of the band smashed their instruments to bits at full volume.
These days, one of Pete Townshend’s favorite charities is H.E.A.R., Hearing Education and Awareness for Rockers, founded in San Francisco by former bass guitarist Kathy Peck, who suffered severe hearing loss in her early 20s after several years of playing amplified rock. Her mission is to alert people to the risks of high-decibel music and noise, and she actually recommends earplugs for rock and roll concertgoers. But rock and roll isn’t the only threat to our hearing. In our modern industrialized environment, we’re assaulted from every side by a cacophonous world of noise: urban trafffic, highways, airplanes, office machines, lawn mowers, and so on. For entertainment, we strap on stereo headsets or settle into our seats in the digital-surround-sound movie theater, experiencing rocket blasts and explosions or the throbbing roar of a Tyrannosaurus rex.
Over time, these assaults take their toll. A study in the New England Journal of Medicine reported that approximately four percent of people under 45 years of age and 29 percent of those 65 or older have a handicapping loss of hearing that interferes with social or job-related communications. It’s been estimated that more than 28 million Americans have hearing impairment, and the prevalence of hearing loss increases dramatically with age. More than 36 percent of persons over the age of 70 have a handicapping hearing loss. Even more disturbing, many younger people are suffering hearing loss before their time. One study of students at the University of Tennessee found that 60 percent of entering freshman had hearing loss, and 14 percent of them had hearing similar to that of the average 65-year-old. The most probable culprit is noise.
To some extent, hearing loss is another disease of civilization. One study of a Sudanese tribe living deep in the African bush found that people of any age in that community had better hearing than a comparable group of American farmers; and more significantly, the older people heard as well as the young. In addition, some diseases, many related to immune disorders like lupus, are known to cause hearing loss. But medical science classifies hearing loss with age as an "idiopathic" disorder; in other words, we don’t know why, it just happens. While hearing loss is associated to some extent with the loss of neuroepithelial cells in the inner ear and with reduced blood circulation, this is only partly a "natural process." It is certainly precipitated or pushed along by cumulative noxious influences throughout life, including noise trauma, the toxicity of drugs and medications, and other environmental factors.
Noise
It’s increasingly evident that loud sounds can harm hearing, including the loud sounds that more and more are part of our entertainment media, our workplaces, and our urbanized environment. Studies have shown measurable hearing loss in people exposed to high-intensity noise, even noise that’s below OSHA safety thresholds. We should be concerned about cranking up the headphones while jogging, loud rock concerts, and even loud movies, which are increasingly mesmerizing audiences with megabass surround sound and thrilling and perhaps literally deafening audio levels. And noise doesn’t affect just hearing. Studies of noise in hospitals — P.A. systems, medical machinery, hallway conversations — have suggested that high noise levels may raise stress levels in patients and even retard healing. In our increasingly clamorous environment, noise pollution may be every bit as serious a problem in some urbanized areas as air pollution. High ambient noise levels can have real medical consequences, including anxiety disorders, insomnia, stress-related conditions, and syndromes of immune disregulation that we don’t think of as being hearing-related, as well as actual hearing impairment.
We tend to get used to our noisy environments and don’t realize how extreme they are until we spend a night in a country home or inn and find the silence "deafening." So it’s important to be alert to the problem and to take preventive measures. A good rule of thumb for music levels is to keep them low enough to enable you to hear other sounds above the music. It’s especially important to be careful with car stereos and Walkman-type headphones, which can unleash a lot of concentrated sound energy. When you can’t avoid high sound levels, the solution is to use earplugs. These can be made of foam rubber or plastic, and they come with an EPA noise reduction rating on the label. Stuffing cotton or tissue in your ears is not effective.
Noise is measured in decibels, and anything 80 decibels or higher is potentially damaging, particularly over sustained exposure. The louder the sound, the less exposure is needed to cause damage. A lawn mower producing a 95-decibel sound level will cause hearing loss in four hours, while a rock concert or stereo headset producing 110 decibels can cause damage in half an hour. Sitting for two hours in a surround-sound movie theater listening to gun battles, explosions, rocket launchings, and dinosaur roars can be a risky experience. You may notice temporary hearing loss or ringing in the ears after such an exposure, or you may not, but repeated exposure over the years can be damaging. The highest noise reduction rating you can generally find from earplugs available in a drugstore is about 30 decibels, which is not really strong enough for four hours at a rock concert, but is certainly better than nothing. A lower rating, say 15 decibels, can be used for running the lawn mower or going to see the latest Schwarzenegger extravaganza.
Drugs and Medications
Many drugs and medications are ototoxic — that is, they can cause hearing loss. They range from some common antibiotics to sophisticated designer drugs to...aspirin! Yes, aspirin and other so-called salicylates have been associated with hearing loss and ringing in the ears, especially with high dosages or long-term use. Studies have shown that aspirin combined with noise exposure has a synergistic effect: people who work in a noisy environment and also self-medicate with aspirin suffer greater hearing degradation than would be expected from simply adding the two factors.
Some diuretics can cause hearing loss, including Lasix, which is commonly used for older patients with congestive heart failure. The anticancer agents used in chemotherapy are frequently ototoxic — we are increasingly seeing loss of hearing sensitivity in younger and middle-aged people who are given chemotherapy, especially women with breast cancer. Some antibiotics can also cause hearing loss, especially those of the aminoglycoside family. These are powerful antibiotics used often in treatment of surgical patients, or elderly or immune-compromised individuals. Some susceptible individuals may even suffer hearing impairment with long courses of more common antibiotics, such as erythromycin or the penicillin derivative amoxicillin.
In fact, a recent study of ear infections in adults (otitis media, the infection of the inner ear that is common in children) found that adults who took antibiotics had a slightly lower rate of recovery in clinical tests than those who took no antibiotics, and those with a history of prophylactic or preventive antibiotic use also had a lower rate of recovery. (A.I.M. Bartelds, et al., "Acute Otitis Media in Adults: A Report from the International Primary Care Network." Journal of American Board of Family Practice 6, July/August 1993, 333-9.) In light of this, the government has put out a position paper recommending conservative use of antibiotic treatment for children with ear infections, which usually get better without treatment. Unfortunately, individual pediatricians remain at the mercy of practice standards in their communities, in a medical/legal climate that pushes them into prescribing medication to prevent the very remote but real possibility of hearing loss and consequent liability. No one gets sued for prescribing antibiotics, even if their long-term effects may be adverse. We tend to aggressively treat kids with antibiotics for their ear ailments to ward off the specter of deafness. Yet, studies show that food allergies are more often the culprit of ear problems in kids, and the vast majority of otitis media infections will resolve themselves spontaneously, without antibiotics.
At the same time, the number of myringotomies — surgical procedures to open up the ear tubes — has skyrocketed, replacing tonsil surgery as the most common type of ear, nose, and throat surgery. Myringotomy is commonly prescribed for children, and involves inserting a tube to remove fluid from the blocked middle ear, thus relieving uncomfortable pressure on the inner ear. In our childhood everybody was getting tonsillectomies, which are now completely out of fashion, and now kids are getting myringotomies. Yet, these surgical procedures and aggressive antibiotic therapies may start to weaken the auditory system even in childhood. What’s more, I think the phenomenon of ototoxic reactions should remind us to be cautious about the use of antibiotics in particular, and the use of other powerful drugs in general.
That Ringing in the Ears
Many factors influence tinnitus. Circulatory impairment and blood viscosity may predispose a person to having the syndrome, along with rapid or extreme fluctuations in blood sugar. (People taking medication for high blood pressure often complain of tinnitus as a side effect of the drug.) Managing cholesterol levels and the types of fats and oils in the diet can sometimes have a positive effect. Other therapies that sometimes help are the use of niacin, and the use of Ginkgo biloba as a circulatory-enhancing agent. Even acupuncture can be helpful, which suggests a relationship to an imbalance of the autonomic nerves that control circulation in the inner ear. Sometimes an injection of a local anesthetic near the ear (called neural therapy in Germany) will cause tinnitus and dizziness to abate, possibly because it rebalances autonomic nerve activity.
There appear to be some nutritional components to tinnitus as well. One study of army personnel with chronic tinnitus and noise-induced hearing loss found significant deficiency of vitamin B12. Supplementation to restore normal blood levels caused some improvement in some patients. Other studies have suggested the potential of zinc and of magnesium supplements to improve chronic tinnitus in those who suffer some deficiency. One interesting study set up a multifaceted dietary plan for people with confirmed hearing loss and tinnitus who hadn’t been helped by medical therapy. These subjects followed a diet with such elements as reduced sodium, reduced saturated fats, reduced animal protein, elimination of refined sugars, and increased whole, raw foods such as vegetables, nuts, and seeds. Most showed improvement in hearing thresholds and tinnitus. The implication is that hearing improvement may depend on multiple health factors. Again, more research needs to be done in this area.
Treating Hearing Loss
Hearing aids are still the mainstay of treating hearing loss, but we now have smaller and more dependable aids, some fitting entirely within the external auditory canal, with programmable amplification circuits that can reduce distortion. In the future, we may look to greater use of totally implantable aids, the so-called cochlear implants, which are designed to reproduce the electrical output of the auditory apparatus and to stimulate the nervous system directly. Since hearing is many orders of magnitude less complex than vision, it’s easier to tackle, with some sound fidelity, the engineering of an artificial receiver and implantable miniaturized system of directly stimulating the nervous system and brain.
This technology already exists, though it’s now a fairly rare, expensive, and experimental practice. It is used in some children and younger people who have profound genetic deafness. No one has tried using this with older people, though that may come. We could think of a cochlear implant as the prototypical artificial sense organ. Given the amazing developments in computer miniaturization, it’s not pure fantasy to envision a time of replaceable sense organs, which could gather sound or light for direct processing by the nervous system and brain, with a degree of miniaturization and fidelity that could rival that of our marvelous eyes and ears.
Dr. Ronald Hoffman is Medical Director of the Hoffman Center in New York City and host of Health Talk, a syndicated radio program heard weeknights in New York on WOR (710 AM) from 9:00 to 10:00 pm, Saturdays noon to 2:00 pm. He is author of several books, including Intelligent Medicine (Fireside, 1997). Dr. Hoffman’s website contains useful health information.