Some perceive it as a high-pitched, mosquito-like squeal; others, an incessant electrical buzzing. It can even sound like unintelligible voices or music. It's known as tinnitus, and it's a surprisingly common affliction, affecting some 50 million people in America alone. Here's why it happens, and how you can prevent it.
Tinnitus (Latin for "ringing") is a condition characterized by a perceived ringing, swishing, hissing, humming, roaring, beeping, sizzling, steady tones or tunes coming from one or both ears or from inside the head. It's surprisingly common, affecting 10 - 20 percent of Americans, only 1 - 2 percent severely enough that medical treatment is needed. Tinnitus is not a disease itself, but rather typically a symptom of an underlying condition.
These conditions can include ear infections, an obstruction of the ear canal (either wax or foreign objects like earwigs), age-related hearing loss, stress, nasal infections, abnormal growth of the ear bones, blood vessel disorders, a wide variety of neurological disorders such as multiple sclerosis or Meniere's disease. None of which is particularly pleasant.
The most common cause, though, is prolonged exposure to excessive noice (above 70 dB; think vacuum cleaner and louder) without sufficient hearing protection. In fact, an estimated 90 percent of tinnitus sufferers also experience some degree of noise-induced hearing loss.
That's not to say the tinnitus causes hearing loss, or vice versa. It's just that the two often appear in concert because of how your ear is designed.
Your inner ear's cochlea is lined with thousands of fine, hair-like cells that vibrate when exposed to sound waves. These vibrations are then converted to electrical signals by cells at the hair's base, form a neural feedback loop which is regulated by the brain. This neural loop normally allows us to pick up very faint and distant sounds by detecting subtle changes in the vibrations of various hairs. But when these hairs are damaged or killed by repeated loud noise exposure, the underlying neurons remain active, sending a false signal to the brain that there is incoming sound when there really isn't.
That's tinnitus. It's equivalent the hum of an amp when you crank it up to 11.
Tinnitus can also be induced by a variety of medications—ranging from asprin and antibiotics to cancer and Malaria treatments. According to the British Tinnitus Association:
Quinine and some of the other anti-malarial drugs can occasionally cause damage to the ear when given in high or prolonged doses, such as in the treatment of malaria. However, taken in low doses to prevent malaria or to relieve night cramps, this does not usually happen. In the rare cases where people on these low doses of quinine do report tinnitus it is temporary and ceases as soon as they discontinue the medication.
There is a small group of very specialized, powerful antibiotics that can be ototoxic – in other words they can damage the inner ear. This damage can cause hearing loss and a small number of the affected people develop tinnitus as a consequence of this hearing loss. This group is known as the aminoglycoside antibiotics and includes streptomycin and gentamicin (Selimoglu 2007). These drugs are not available as tablets, syrups or other oral preparations and are generally given by injection in hospital for severe, life threatening infections.
Outside of avoiding ototoxic medications and quinine, the best treatment for tinnitus is prevention. Be sure to wear proper ear protection when going to concerts, using heavy machinery or landscaping equipment—basically any time it gets louder than 70 dB.
For those that already suffer from Tinnitus, there is no FDA-approved medication available to treat it, though treating the underlying cause often relieves the ringing. Additionally, though therapeutic devices like hearing aids or tinnitus maskers (which broadcast a specific noise frequency that matches and "cancels out" the tinnitus' frequency) though their effectiveness has yet to be really proven. Still, there's little harm in giving them a shot if your doctor doesn't object. Anything is better than enduring that constant hum in your head. [Wiki - Medical News Today - WebMD - BTA]
Images: Top - Image Point Fr, Ear - Chittka L, Brockmann A