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.
Tinnitus (pronounced tih-NITE-us or TIN-ih-tus) is sound in the head with no external source. For many, it's a ringing sound, while for others, it's whistling, buzzing, chirping, hissing, humming, roaring, or even shrieking. The sound may seem to come from one ear or both, from inside the head, or from a distance. It may be constant or intermittent, steady or pulsating.
Sound therapy can be effective in treating tinnitus because it may make the tinnitus less noticeable or mask the tinnitus or fade tinnitus. Hearing aids are included as a critical component of a sound therapy program. Modern hearing aids come with a special tinnitus managing sounds along with digital amplification. They are much evolved over the older technology. Different products work in different ways, although most hearing aids can alleviate tinnitus, certain hearing aids have built-in technology specifically for tinnitus relief. At amplifon, we have a clearly defined way to measure and quantify chronic tinnitus. As per the severity of the problem, an appropriate combination of treatment methods is selected to deal with your tinnitus. Amplifon audiologists are specially trained in counselling procedures as well which is another critical element of sound therapy. Consult your Amplifon audiologist to find more details about what suits you to deal with your tinnitus problem.
Other causes of tinnitus include middle ear infections, disorders that block the ear canal (such as an external ear infection [external otitis], excessive ear wax, or foreign bodies), problems with the eustachian tube (which connects the middle ear and the back of the nose) due to allergies or other causes of obstruction, otosclerosis (a disorder of excess bone growth in the middle ear), and temporomandibular disorders. An uncommon but serious cause is an acoustic neuroma, a noncancerous (benign) tumor of part of the nerve leading from the inner ear.
Tinnitus can arise anywhere along the auditory pathway, from the outer ear through the middle and inner ear to the brain's auditory cortex, where it's thought to be encoded (in a sense, imprinted). One of the most common causes of tinnitus is damage to the hair cells in the cochlea (see "Auditory pathways and tinnitus"). These cells help transform sound waves into nerve signals. If the auditory pathways or circuits in the brain don't receive the signals they're expecting from the cochlea, the brain in effect "turns up the gain" on those pathways in an effort to detect the signal — in much the same way that you turn up the volume on a car radio when you're trying to find a station's signal. The resulting electrical noise takes the form of tinnitus — a sound that is high-pitched if hearing loss is in the high-frequency range and low-pitched if it's in the low-frequency range. This kind of tinnitus resembles phantom limb pain in an amputee — the brain is producing abnormal nerve signals to compensate for missing input.
It is important to follow the doctor's directions in obtaining further evaluations and tests for your tinnitus. You may need an appointment with an ear, nose, and throat specialist (otolaryngologist) or an audiologist for further testing. It is important to follow up on these recommendations when they are made to confirm that your tinnitus is not caused by another illness.
Dr. Ben Wedro practices emergency medicine at Gundersen Clinic, a regional trauma center in La Crosse, Wisconsin. His background includes undergraduate and medical studies at the University of Alberta, a Family Practice internship at Queen's University in Kingston, Ontario and residency training in Emergency Medicine at the University of Oklahoma Health Sciences Center.
In persons with pulsatile tinnitus, additional tests maybe proposed to study the blood vessels and to check the pressure inside the head. Gentle pressure on the neck can be performed to block the jugular vein but not the carotid artery. The Valsalva maneuver reduces venous return by increasing intrathoracic pressure. If there is a venous hum, this usually abates or improves markedly. If the pulsation is arterial, these tests have no effect.
While there may be a wide range of causes, an important underlying factor for the development of tinnitus is brain plasticity.5,7 This property allows the brain to change and adapt, and it is essential to how we learn. Unfortunately, in some cases, such as with hearing loss, the auditory part of the brain may be altered as brain plasticity tries to compensate for the abnormal auditory inputs. This response leads to changes in brain activity in the auditory system (e.g., the auditory cortex) that can create a phantom percept: tinnitus. As such, while tinnitus may begin a problem at the auditory periphery, it persists because of changes throughout the auditory system. Treating tinnitus may require addressing both the initiator (e.g., hearing loss) and the driver (changes in the auditory brain).
Millions of Americans experience tinnitus, often to a debilitating degree, making it one of the most common health conditions in the country. The U.S. Centers for Disease Control estimates that nearly 15% of the general public — over 50 million Americans — experience some form of tinnitus. Roughly 20 million people struggle with burdensome chronic tinnitus, while 2 million have extreme and debilitating cases.1