The researchers paired electrical stimulation of the vagus nerve — a large nerve that runs from the head to the abdomen — with the playing of a tone. Vagus nerve stimulation (VNS) is known to release chemicals that encourage changes in the brain. This technique, the scientists reasoned, might induce brain cells (neurons) to tune to frequencies other than the tinnitus one. For 20 days, 300 times a day, they played a high-pitched tone to 8 rats during VNS.
Tinnitus – a sound in the head with no external source – is not a disease; it is a symptom that can be triggered by a variety of different health conditions. So what causes tinnitus? Common sources include hearing loss, ear wax buildup, ototoxic medications, and ear bone changes. No matter what the cause, the condition interrupts the transmission of sound from the ear to the brain. Some part of the hearing system is involved as well, whether the outer, middle, or inner ear.
Overdosing on certain prescription drugs, recreational drugs or alcohol. This can sometimes cause permanent damage to nerves that affect hearing. In some cases when a pregnant women uses drugs during pregnancy, this can cause tinnitus to develop in her child. Common drugs that might contribute to tinnitus include ototoxics, psychotropic drugs, aminoglycosides, certain antibiotics and vancomycin.
Some persons with severe TMJ (temporomandibular joint) arthritis have severe tinnitus. Generally these persons say that there is a "screeching" sound. This is another somatic tinnitus. TMJ is extremely common -- about 25% of the population. The exact prevalence of TMJ associated tinnitus is not established, but presumably it is rather high too. Having TMJ increases the odds that you have tinnitus too, by about a factor of 1.6-3.22 (Park and Moon, 2014; Lee et al, 2016). This is the a large risk factor for tinnitus, similar to the risk from hearing loss (see table above).
Tinnitus is not a disease but a symptom that can result from a number of underlying causes. One of the most common causes is noise-induced hearing loss. Other causes include ear infections, disease of the heart or blood vessels, Ménière's disease, brain tumors, emotional stress, exposure to certain medications, a previous head injury, and earwax. It is more common in those with depression.
Most people should have a formal hearing test done by either the doctor or a hearing specialist (audiologist). People with tinnitus in only one ear and hearing loss should have gadolinium-enhanced magnetic resonance imaging (MRI). People with tinnitus in only one ear and normal hearing should have an MRI if tinnitus lasts more than 6 months. People with pulsatile tinnitus often require magnetic resonance angiography (MRA) and sometimes angiography.
Most experts refer to tinnitus as the condition that causes ringing in the ears, however other abnormal sounds and sensations can also be attributed to tinnitus. The definition of tinnitus is “the perception of noise or ringing in the ears.” Some also describe this condition as “hearing sounds in the ears when no external sound is present.” Although tinnitus is only a significant problem for about 1 percent to 5 percent of the population, up to 10 percent to 15 percent of all children and adults are believed to experience ringing in the ears at least from time to time.
About six percent of the general population has what they consider to be "severe" tinnitus. That is a gigantic number of people ! Tinnitus is more common with advancing age. In a large study of more than 2000 adults aged 50 and above, 30.3% reported having experienced tinnitus, with 48% reporting symptoms in both ears. Tinnitus had been present for at least 6 years in 50% of cases, and most (55%) reported a gradual onset. Tinnitus was described as mildly to extremely annoying by 67%.(Sindhusake et al. 2003)
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.
Most people who suffer from tinnitus also experience hearing loss to some degree. As they often accompany one another, the two conditions may be correlated. In fact, some researchers believe that subjective tinnitus can only occur if the auditory system has been previously damaged (source). The loss of certain sound frequencies due to hearing loss may change how the brain processes sound, causing it to adapt and fill in the gaps with tinnitus. The underlying hearing loss typically results from exposure to loud noises or advanced age:
There is no cure for tinnitus. However, it can be temporary or persistant, mild or severe, gradual or instant. The goal of treatment is to help you manage your perception of the sound in your head. There are many treatments available that can help reduce the perceived intensity of tinnitus, as well as its omnipresence. Tinnitus remedies may not be able to stop the perceived sound, but they can improve your quality of life.
Use other relaxation techniques. Tinnitus is understandably anxiety provoking, often a source of frustration and stress throughout the day and night. Reducing anxiety, and finding ways to relax, have benefits for both tinnitus and sleep. Relaxation exercises can reduce the aggravation of tinnitus, and make you more able to fall asleep. A few of the relaxation techniques my patients find most effective and easy to use are:
The diagnosis of tinnitus is usually based on the person's description. A number of questionnaires exist that may help to assess how much tinnitus is interfering with a person's life. The diagnosis is commonly supported by an audiogram and a neurological examination. If certain problems are found, medical imaging, such as with MRI, may be performed. Other tests are suitable when tinnitus occurs with the same rhythm as the heartbeat. Rarely, the sound may be heard by someone else using a stethoscope, in which case it is known as objective tinnitus. Spontaneous otoacoustic emissions, which are sounds produced normally by the inner ear, may also occasionally result in tinnitus.
Michael Chrostowski, PhD is the founder of Sound Options Tinnitus Treatments Inc. His dedication to improving the lives of tinnitus sufferers drives his vision of providing effective, affordable and accessible treatments for the many tinnitus sufferers he has met throughout his research career. With over 8 years of research in the field of tinnitus and collaborations with leaders in the field, Dr. Chrostowski was able to make use of cutting-edge research to develop software that can customize an effective and personal treatment for tinnitus. Dr. Chrostowski received a BASc in electrical and computer engineering at the University of Toronto and a PhD in neuroscience at McMaster University.
Another example of somatic tinnitus is that caused by temperomandibular joint disorder. The temporomandibular joint (TMJ) is where the lower jaw connects to the skull, and is located in front of the ears. Damage to the muscles, ligaments, or cartilage in the TMJ can lead to tinnitus symptoms. The TMJ is adjacent to the auditory system and shares some ligaments and nerve connections with structures in the middle ear.
Tinnitus can be extremely frustrating and can leave you feeling overwhelmed and unsure about your next steps. Remember that you are not alone - tinnitus, while not well-understood, is common. Make an appointment with a hearing care professional near you, preferably one who specializes in tinnitus treatment. Be prepared to discuss your symptoms in detail so you can get relief and regain your quality of life.