Sound waves travel through the ear canal to the middle and inner ear, where hair cells in part of the cochlea help transform sound waves into electrical signals that then travel to the brain's auditory cortex via the auditory nerve. When hair cells are damaged — by loud noise or ototoxic drugs, for example — the circuits in the brain don't receive the signals they're expecting. This stimulates abnormal activity in the neurons, which results in the illusion of sound, or tinnitus.
For many, tinnitus symptoms come on gradually and eventually go away as the brain and ears adjust. However, for others tinnitus can last for years and cause various complications. A high percentage of people with tinnitus that’s persistent and untreatable go on to also develop anxiety or depression as a result. What types of things can you do to deal with and lower tinnitus symptoms? Tinnitus treatment includes avoiding excessively loud sources of noise pollution, using certain hearing aids, preventing ear infections and avoiding drug use.
If you’re struggling with tinnitus and experience anxiety or depression relating to your condition, cognitive behavioural therapy is a form of counselling that helps you to cope and readjust your negative feelings. Tinnitus retraining therapy (TRT) can also be used in conjunction with CBT, harnessing the body's natural ability to tune out sounds and make it part of your subconscious mind rather than at the forefront.
John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.
TRT depends upon the natural ability of the brain to "habituate" a signal, to filter it out on a subconscious level so that it does not reach conscious perception. Habituation requires no conscious effort. People frequently habituate many auditory sounds -- air conditioners, computer fans, refrigerators, and gentle rain, among them. What they have in common is that they have no importance, so they are not perceived as ''loud.'' Thus, the brain can screen them out.
Individuals with tinnitus describe perceiving a wide variety of sounds including ringing, clicking, hissing, humming, chirping, buzzing, whistling, whooshing, roaring, and/or whirling. These sounds may be present at all times, or they may come and go. The volume, pitch or quality of tinnitus sounds can fluctuate as well. Some people report that their tinnitus is most obvious when outside sounds are low (i.e. during the night). Other individuals describe their tinnitus as loud even in the presence of external sounds or noise, and some describe it as exacerbated by sounds. Tinnitus can affect one ear or both ears. It can also sound like it is inside the head and not in the ears at all.
Some people experience a sound that beats in time with their pulse, known as pulsatile tinnitus or vascular tinnitus. Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow, increased blood turbulence near the ear, such as from atherosclerosis or venous hum, but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear. Rarely, pulsatile tinnitus may be a symptom of potentially life-threatening conditions such as carotid artery aneurysm or carotid artery dissection. Pulsatile tinnitus may also indicate vasculitis, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be an indication of idiopathic intracranial hypertension. Pulsatile tinnitus can be a symptom of intracranial vascular abnormalities and should be evaluated for irregular noises of blood flow (bruits).
Hearing loss: Probably the most common cause for tinnitus is hearing loss. As we age, or because of trauma to the ear (through noise, drugs, or chemicals), the portion of the ear that allows us to hear, the cochlea, becomes damaged. Current theories suggest that because the cochlea is no longer sending the normal signals to the brain, the brain becomes confused and essentially develops its own noise to make up for the lack of normal sound signals. This then is interpreted as a sound, tinnitus. This tinnitus can be made worse by anything that makes our hearing worse, such as ear infections or excess wax in the ear.
The researchers next tested whether tinnitus could be reversed in noise-exposed rats. The animals received VNS paired with various tones other than the tinnitus frequency 300 times a day for about 3 weeks. Rats that received the treatment showed behavioral changes indicating that the ringing had stopped. Neural responses in the brain's auditory cortex returned to their normal levels as well, indicating that the tinnitus had disappeared.