What is tinnitus?
Tinnitus is the illusion of sound when there is none. It may be a ringing, roaring, clicking, hissing, or buzzing sound in the ears. It may occur in one or both ears, be soft or loud, high pitched or low pitched. Approximately 10 percent of the adult population of the United States has experienced tinnitus for more than three months.
What causes tinnitus?
Tinnitus (pronounced tin-NY-tus or TIN-u-tus) indicates something is wrong in the auditory system (the ear, the auditory nerve that connects the inner ear to the brain, or the parts of the brain that process sound). Earwax may be blocking the ear canal, or it can be the result of a number of health conditions, including:
- Noise-induced hearing loss
- Ear and sinus infections
- Diseases of the heart or blood vessels
- Ménière’s disease
- Brain tumors
- Hormonal changes in women
- Thyroid abnormalities
Tinnitus can be the first sign of hearing loss in older people or a side effect of medications. More than 200 drugs are known to cause tinnitus when you start or stop taking them.
Noise exposure is a common cause of tinnitus. Factory or construction workers, road crews, and musicians can develop tinnitus over time when ongoing exposure to noise damages tiny sensory hair cells in the inner ear that help transmit sound to the brain.
Soldiers exposed to bomb blasts can develop tinnitus if the shock wave of the explosion squeezes the skull and damages brain tissue in areas that help process sound.
Pulsatile tinnitus, a rhythmic pulsing in the ear usually in time with your heartbeat, is a rare type of tinnitus most often caused by problems with blood flow in the head or neck. A doctor may be able to hear it by pressing a stethoscope against your neck or by placing a tiny microphone inside the ear canal. Pulsatile tinnitus also may be caused by brain tumors or abnormalities in brain structure.
Some people develop tinnitus for no obvious reason. Most of the time, tinnitus isn’t a sign of a serious health problem, although if it’s loud or doesn’t go away, it can cause fatigue, depression, anxiety, and memory and concentration problems. For some, it is a source of mental and emotional anguish.
Why do I have this noise in my ears?
Although tinnitus sounds as if it is in our ears, it really is in the neural circuits or networks of brain cells. Tinnitus may begin in the ear, but it continues in the brain. Some think that tinnitus is similar to chronic pain syndrome, in which the pain persists even after a wound or broken bone has healed.
Scientists are unsure of what causes tinnitus. Some think it the result of the brain’s neural circuits trying to adapt to the loss of sensory hair cells by turning up the sensitivity to sound. This would explain why some people with tinnitus are oversensitive to loud noise.
Or damage in the inner ear may change signaling activity in the auditory cortex, the part of the brain that processes sound. Or abnormal interactions between neural circuits could cause tinnitus.
What should I do if I have tinnitus?
Check with your primary care doctor to be sure nothing is blocking your ear canal, such as earwax.
If your doctor cannot find any medical reason for your tinnitus, you may be referred to an otolaryngologist (also known as an ear, nose, and throat an ENT doctor). The ENT will physically examine your head, neck, and ears and test your hearing to determine whether you have any hearing loss along with the tinnitus. You might also be referred to an audiologist who can also measure your hearing and evaluate your tinnitus.
What if the sounds in my ear do not go away?
Tinnitus may continue or get worse. It may become so severe that it becomes difficult to hear, concentrate or even sleep. Your doctor will work with you to help find ways to reduce the severity of the noise and its impact on your life.
Are there treatments that can help me?
Tinnitus isn’t curable yet. Below are some treatments that doctors may recommend and that have helped people cope with the condition.
Hearing aids can be helpful for people who have hearing loss along with tinnitus. Using a hearing aid adjusted to carefully control outside sound levels may make it easier for you to hear. The better you hear, the less you may notice your tinnitus.
Counseling may help you change the way you think about and react to your tinnitus. You may learn some things to make the noise less noticeable, to help you relax during the day or to fall asleep at night.
Wearable sound generators are small electronic devices that fit in the ear and use a soft, pleasant sound to help mask the tinnitus. Some people want the masking sound to totally cover up their tinnitus, but most prefer a masking level that is just a bit louder than their tinnitus. The masking sound can be a soft “shhhhhhhhhhh,” random tones, or music.
Tabletop sound generators are used as an aid for relaxation or sleep. Placed near your bed, you can program a generator to play pleasant sounds such as waves, waterfalls, rain, or the sounds of a summer night. If your tinnitus is mild, this might be all you need to help you fall asleep.
Acoustic neural stimulation is a relatively new technique for people whose tinnitus is very loud or won’t go away. It uses a palm-sized device and headphones to deliver a broadband acoustic signal embedded in music. The treatment helps stimulate change in the neural circuits in the brain, which eventually desensitizes you to the tinnitus. The device has been shown to be effective in reducing or eliminating tinnitus in a significant number of study volunteers.
Cochlear implants are sometimes used in people who have tinnitus along with severe hearing loss. A cochlear implant bypasses the damaged portion of the inner ear and sends electrical signals that directly stimulate the auditory nerve. The device brings in outside sounds that help mask tinnitus and stimulate change in the neural circuits.
Antidepressants and anti-anxiety drugs might be prescribed by your doctor to improve your mood and help you sleep.
Other medications may be available at drugstores and on the Internet as an alternative remedy for tinnitus, but none of these preparations has been proved effective in clinical trials.
Can I do anything to prevent tinnitus or keep it from getting worse?
Noise-induced hearing loss, the result of damage to the sensory hair cells of the inner ear, is one of the most common causes of tinnitus. Anything you can do to limit your exposure to loud noise—by moving away from the sound, turning down the volume, or wearing earplugs or earmuffs—will help prevent tinnitus or keep it from getting worse.
What are researchers doing to better understand tinnitus?
Many things can go wrong along the path a sound travels from the inner ear to the brain to cause tinnitus.
Promising research directions include:
- Electrical or magnetic stimulation of brain areas involved in hearing. Implantable devices already exist to reduce the trembling of Parkinson’s disease and the anxieties of obsessive-compulsive disorder. Similar devices could be developed to normalize the neural circuits involved in tinnitus.
- Repetitive transcranial magnetic stimulation (rTMS). This technique, which uses a small device placed on the scalp to generate short magnetic pulses, is used to normalize electrical activity in the brains of people with epilepsy. Through preliminary trials of rTMS in humans, researchers are looking for the best spots to stimulate in the brain in order to suppress tinnitus. The National Institute of Deafness and Communication Disorders funds these studies. Researchers are also looking for ways to identify which people are most likely to respond well to stimulation devices.
- Hyperactivity and deep brain stimulation. Researchers have observed hyperactivity in neural networks after exposing the ear to intense noise. Understanding specifically where in the brain this hyperactivity begins and how it spreads to other areas could lead to treatments that use deep brain stimulation to calm the neural networks and reduce tinnitus.
- Resetting the tonotopic map. Researchers are exploring how to take advantage of the tonotopic map, which organizes neurons in the auditory cortex according to the frequency of the sound to which they respond. Previous research has shown a change in the organization of the tonotopic map after exposing the ear to intense noise. By understanding how these changes happen, researchers could develop techniques to bring the map back to normal and relieve tinnitus.
The NIDCD maintains a directory of organizations that provide information on the normal and disordered processes of hearing, balance, smell, taste, voice, speech, and language. Please see the list of organizations at www.nidcd.nih.gov/directory.
Primary source: National Institutes of Health
Note: If no author is given, the source is cited instead.
Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of HearingLab or its staff.