An assessment of hyperacusis, a frequent accompaniment of tinnitus,[56] may also be made.[57] The measured parameter is Loudness Discomfort Level (LDL) in dB, the subjective level of acute discomfort at specified frequencies over the frequency range of hearing. This defines a dynamic range between the hearing threshold at that frequency and the loudnes discomfort level. A compressed dynamic range over a particular frequency range is associated with subjectve hyperacusis. Normal hearing threshold is generally defined as 0–20 decibels (dB). Normal loudness discomfort levels are 85–90+ dB, with some authorities citing 100 dB. A dynamic range of 55 dB or less is indicative of hyperacusis.[58][59]
Along the path a hearing signal travels to get from the inner ear to the brain, there are many places where things can go wrong to cause tinnitus. If scientists can understand what goes on in the brain to start tinnitus and cause it to persist, they can look for those places in the system where a therapeutic intervention could stop tinnitus in its tracks.

Superior semicircular canal dehiscence syndrome is another not uncommon cause of pulsatile tinnitus. The superior semicircular canal is one of three canals found in the vestibular apparatus of the inner ear. The vestibular apparatus helps to maintain equilibrium and balance. In this syndrome, a part of the temporal bone that overlies the superior semicircular canal is abnormally thin or absent. Superior semicircular canal dehiscence syndrome can affect both hearing and balance to different degrees.


Unfortunately that means tinnitus is a very complicated condition that involves several systems of the body. The good news, though, is that as doctors and researchers have developed a better understanding of the mechanisms behind tinnitus, they’ve also been able to develop new and promising treatments that target the brain rather than the ear — and have more of a chance of actually reversing the problem.
Take medication for a thyroid disorder, if necessary. Tinnitus can be related to both hyperthyroidism, or an overactive thyroid, and hypothyroidism, or an underactive thyroid. Your doctor can check for swelling or lumps in your thyroid gland, which is in your throat, and order blood screens to test its function. If they find an issue, they’ll prescribe medication to regulate your thyroid hormone levels.[17]
Cartoon of the middle ear showing muscles that attach to ossicles (ear bones), and ear drum. The stapedius is attached to the stapes (of course -- horseshoe object above), while the tensor tympani is attached to the ear drum. While useful, be aware that there are multiple errors in this illustration from Loyola Medical School. With permission, from: http://www.meddean.luc.edu/lumen/meded/grossanatomy/dissector/mml/images/stap.jpg
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Identifying And Treating Any Vascular Issues. There is a very small chance that your tinnitus is being caused by an underlying blood vessel condition known as pulsatile tinnitus. Sometimes this condition is caused by pregnancy or strenuous exercise and other times it’s the result of a single blood vessel or a group of blood vessels experiencing increased blood flow that the rest of the body is not experiencing. On rare occurrences, the cause is a benign tumor known as an acoustic neuroma (AKA vestibular schwannoma). These tumors, although very rare, can cause the development of abnormal blood vessels which can result in pulsatile tinnitus. Treatment options include medication and surgery.
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.
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