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.
Supporting the idea that central reorganization is overestimated as "the" cause of tinnitus, a recent study by Wineland et al showed no changes in central connectivity of auditory cortex or other key cortical regions (Wineland et al, 2012). Considering other parts of the brain, Ueyama et al (2013) reported that there was increased fMRI activity in the bilateral rectus gyri, as well as cingulate gyri correlating with distress. Loudness was correlated with values in the thalamus, bilateral hippocampus and left caudate. In other words, the changes in the brain associated with tinnitus seem to be associated with emotional reaction (e.g. cingulate), and input systems (e.g. thalamus). There are a few areas whose role is not so obvious (e.g. caudate). This makes a more sense than the Wineland result, but of course, they were measuring different things. MRI studies related to audition or dizziness must be interpreted with great caution as the magnetic field of the MRI stimulates the inner ear, and because MRI scanners are noisy.
In many cases, tinnitus is caused by hyperactivity (or too much activity) in the brain’s auditory cortex. “When there’s damage or a loss of input in the ear [such as hearing loss, head trauma, or a blood vessel problem], the brain tries to turn up certain channels in order to compensate,” Dr. Kilgard explains. When the brain doesn’t get that tuning quite right, the result is tinnitus.
Additional conditions that can cause pulsatile tinnitus include arterial bruit, abnormal passages or connections between the blood vessels of the outermost layer of the membrane (dura) that covers the brain and spinal cord (dural arteriovenous shunts), or conditions that cause increased pressure within the skull such as idiopathic intracranial hypertension (pseudotumor cerebri). Sigmoid sinus dehiscence may be associated with pseudotumor, but this connection has not been firmly established. It possible that cases of pulsatile tinnitus associated with pseudotumor may be caused by an undiagnosed SSWA. Head trauma, surgery, middle ear conductive hearing loss, and certain tumors can also cause pulsatile tinnitus. Obstructions within in the vessels that connect the heart and brain can also cause pulsatile tinnitus.
Noise-induced hearing loss - Exposure to loud noises, either in a single traumatic experience or over time, can damage the auditory system and result in hearing loss and sometimes tinnitus as well. Traumatic noise exposure can happen at work (e.g. loud machinery), at play (e.g. loud sporting events, concerts, recreational activities), and/or by accident (e.g. a backfiring engine.) Noise induced hearing loss is sometimes unilateral (one ear only) and typically causes patients to lose hearing around the frequency of the triggering sound trauma.
FACT: Many people with tinnitus will also have a hearing loss. In fact, a recent French study showed that of 123 people with tinnitus surveyed only one did not have hearing loss. The British Tinnitus Association estimates that 90 percent of people with tinnitus also have a hearing loss. Moreover, research says that those who don’t may have a “hidden hearing loss.”
With respect to incidence (the table above is about prevalence), Martinez et al (2015) reported that there were 5.4 new cases of tinnitus per 10,000 person-years in England. We don't find this statistic much use as tinnitus is highly prevalent in otherwise normal persons. It seems to us that their study is more about how many persons with tinnitus were detected by the health care system -- and that it is more a study of England's health care system than of tinnitus.
There are two types of tinnitus: subjective tinnitus and objective tinnitus. Tinnitus is usually subjective, meaning that there is no sound detectable by other means. Subjective tinnitus has also been called "tinnitus aurium", "non-auditory" or "non-vibratory" tinnitus. In very rare cases tinnitus can be heard by someone else using a stethoscope, and in less rare – but still uncommon – cases it can be measured as a spontaneous otoacoustic emission (SOAE) in the ear canal. In such cases it is objective tinnitus, also called "pseudo-tinnitus" or "vibratory" tinnitus.
If the source of the problem remains unclear, you may be sent to an otologist or an otolaryngologist (both ear specialists) or an audiologist (a hearing specialist) for hearing and nerve tests. As part of your examination, you may be given a hearing test called an audiogram. An imaging technique, such as an MRI or a CT scan, may also be recommended to reveal any structural problem.
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.
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Exposure to loud noise. Loud noises, such as those from heavy equipment, chain saws and firearms, are common sources of noise-related hearing loss. Portable music devices, such as MP3 players or iPods, also can cause noise-related hearing loss if played loudly for long periods. Tinnitus caused by short-term exposure, such as attending a loud concert, usually goes away; both short- and long-term exposure to loud sound can cause permanent damage.