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Tinnitus

Tinnitus

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Tinnitus is the perception of sound within the human ear in the absence of corresponding external sound.

Tinnitus is not a disease, but a symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

 that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period (but usually with some duration), ear infections, foreign objects in the ear, nasal allergies that prevent (or induce) fluid drain, or wax build-up. Withdrawal from a benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...

 addiction may cause tinnitus as well. In-ear headphones, whose sound enters directly into the ear canal without any opportunity to be deflected or absorbed elsewhere, is a common cause of tinnitus when volume is set beyond moderate levels.

Tinnitus can also be caused by natural hearing impairment (as is often seen in aging), as a side effect
Side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequences of the use of a drug.Occasionally, drugs are...

 of some medications, and as a side effect of genetic (congenital) hearing loss. However, the most common cause is noise-induced hearing loss.

As tinnitus is usually a false subjective phenomenon, it is difficult to measure using objective tests, such as by comparison with noise of known frequency and intensity, as in an audiometric test
Audiometry
Audiometry is the testing of hearing ability, involving thresholds and differing frequencies. Typically, audiometric tests determine a subject's hearing levels with the help of an audiometer, but may also measure ability to discriminate between different sound intensities, recognize pitch, or...

. The condition is often rated clinically on a simple scale from "slight" to "catastrophic" according to the practical difficulties it imposes, such as interference with sleep, quiet activities, and normal daily activities.

Tinnitus is common; about 20% of people between 55 and 65 years old report symptoms on a general health questionnaire, and 11.8% on more detailed tinnitus-specific questionnaires.

Characteristics


Tinnitus can be perceived in one or both ears or in the head. It is usually described as a ringing noise, but in some patients, it takes the form of a high-pitched whining, electric buzzing, hissing, humming, tinging or whistling sound, or as ticking, clicking, roaring, "crickets" or "tree frogs" or "locusts (cicada
Cicada
A cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha , in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the world, and many of them remain unclassified...

s)", tunes, songs, beeping, or even a pure steady tone like that heard during a hearing test. It has also been described as a "wooshing" sound, as of wind or waves. Tinnitus can be intermittent, or it can be continuous, in which case it can be the cause of great distress. In some individuals, the intensity can be changed by shoulder, head, tongue, jaw, or eye movements.

Most people with tinnitus have some degree of hearing loss, in that they are often unable to hear clearly external sounds that occur within the same range of frequencies as their "phantom sounds". This has led to the suggestion that one cause of tinnitus might be a homeostatic response of central dorsal cochlear nucleus
Dorsal cochlear nucleus
The dorsal cochlear nucleus , is a cortex-like structure on the dorso-lateral surface of the brainstem...

 auditory neurons that makes them hyperactive in compensation to auditory input loss.

The sound perceived may range from a quiet background noise to one that can be heard even over loud external sounds. The term tinnitus usually refers to more severe cases. Heller and Bergman (1953) conducted a study of 100 tinnitus-free university students placed in an anechoic chamber
Anechoic chamber
An anechoic chamber is a room designed to stop reflections of either sound or electromagnetic waves.They are also insulated from exterior sources of noise...

 and found 93% reported hearing a buzzing, pulsing or whistling sound. Cohort studies have demonstrated damage to hearing (among other health effects
Noise health effects
Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance and sleep disturbance. Changes in the immune system and birth defects have been attributed to noise exposure...

) from unnatural levels of noise exposure is very widespread in industrialized countries.

For research purposes, the more elaborate Tinnitus Handicap Inventory is often used. Persistent tinnitus may cause irritability, fatigue, and on occasions, clinical depression and musical hallucinations.

As with all diagnostics, other potential sources of the sounds normally associated with tinnitus should be ruled out. For instance, two recognized sources of very high pitched sounds might be electromagnetic fields common in modern wiring and various sound signal transmissions. A common and often misdiagnosed condition that mimics tinnitus is Radio Frequency (RF) Hearing, in which subjects have been tested and found to hear high-pitched transmission frequencies that sound similar to tinnitus.

Objective tinnitus


In some cases, a clinician can perceive an actual sound (e.g., a bruit
Bruit
Bruit is the term for the unusual sound that blood makes when it rushes past an obstruction in an artery when the sound is auscultated with the bell portion of a stethoscope.The term "bruit" simply refers to the sound...

) emanating from the patient's ears. This is called objective tinnitus. Objective tinnitus can arise from muscle spasms that cause clicks or crackling around the middle ear. Some people experience a sound that beats in time with the pulse (pulsatile tinnitus, or vascular tinnitus). Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow or increased blood turbulence near the ear (such as from atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

 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
Carotid artery
Carotid artery can refer to:* Common carotid artery* External carotid artery* Internal carotid artery...

 aneurysm
Aneurysm
An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...

 or carotid artery dissection
Carotid artery dissection
Carotid artery dissection is a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain, and is the most common cause of stroke in young adults...

. Pulsatile tinnitus may also indicate vasculitis
Vasculitis
Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...

, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be an indication of idiopathic intracranial hypertension
Idiopathic intracranial hypertension
Idiopathic intracranial hypertension , sometimes called by the older names benign intracranial hypertension or pseudotumor cerebri , is a neurological disorder that is characterized by increased intracranial pressure in the absence of a tumor or other diseases...

.

Subjective tinnitus


Subjective tinnitus can have many possible causes, but most commonly results from otologic disorders – the same conditions that cause hearing loss. The most common cause is noise-induced hearing loss, resulting from exposure to excessive or loud noises. Tinnitus, along with sudden onset hearing loss, may have no obvious external cause. Ototoxic
Ototoxicity
Ototoxicity is damage to the ear , specifically the cochlea or auditory nerve and sometimes the vestibular system, by a toxin. It is commonly medication-induced; ototoxic drugs include antibiotics such as the aminoglycoside gentamicin, loop diuretics such as furosemide, and platinum-based...

 drugs can cause subjective tinnitus either secondary to hearing loss or without hearing loss and may increase the damage done by exposure to loud noise, even at doses that are not in themselves ototoxic.

Subjective tinnitus is also a side effect of some medications, such as aspirin
Aspirin
Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

, and may also result from an abnormally low level of serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

 activity. It is also a classical side effect of quinidine
Quinidine
Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree.-Mechanism:...

, a Class IA anti-arrhythmic. Over 260 medications have been reported to cause tinnitus as a side effect. In many cases, however, no underlying physical cause can be identified.

Tinnitus can also occur due to the discontinuation of therapeutic doses of benzodiazepines as part of the benzodiazepine withdrawal syndrome
Benzodiazepine withdrawal syndrome
Benzodiazepine withdrawal syndrome—often abbreviated to benzo withdrawal—is the cluster of symptoms which appear when a person who has taken benzodiazepines long term and has developed benzodiazepine dependence stops taking benzodiazepine drug or during dosage reductions...

. It can sometimes be a protracted symptom from benzodiazepine withdrawal and persist for many months.

Causes of subjective tinnitus include:
  • Otologic problems and hearing loss:
    • conductive hearing loss
      • external ear infection
      • acoustic shock
        Acoustic shock
        The term acoustic shock is used to describe the symptoms a person may experience after hearing an unexpected, loud sound via a telephone. The loud sound, called an Acoustic Incident, can be caused by feedback oscillation, fax tones, or signalling tones....

      • loud noise or music
      • cerumen (earwax
        Earwax
        Earwax, also known by the medical term cerumen, is a yellowish waxy substance secreted in the ear canal of humans and other mammals. It protects the skin of the human ear canal, assists in cleaning and lubrication, and also provides some protection from bacteria, fungi, insects and water...

        ) impaction
      • middle ear effusion
      • superior canal dehiscence
    • sensorineural hearing loss
      Sensorineural hearing loss
      Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve , the inner ear, or central processing centers of the brain....

      • excessive or loud noise
      • presbycusis
        Presbycusis
        Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. Also known as presbyacusis, it is defined as a progressive bilateral symmetrical age-related sensorineural hearing loss. The hearing loss is most marked at higher frequencies...

         (age-associated hearing loss)
      • Ménière's disease
        Ménière's disease
        Ménière's disease is a disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterized by episodes of vertigo and tinnitus and progressive hearing loss, usually in one ear. It is named after the French physician Prosper Ménière, who, in an article published...

      • acoustic neuroma
        Acoustic neuroma
        A vestibular schwannoma, often called an acoustic neuroma, is a benign primary intracranial tumor of the myelin-forming cells of the vestibulocochlear nerve . The term "vestibular schwannoma" involves the vestibular portion of the 8th cranial nerve and arises from Schwann cells, which are...

      • mercury
        Mercury poisoning
        Mercury poisoning is a disease caused by exposure to mercury or its compounds. Mercury is a heavy metal occurring in several forms, all of which can produce toxic effects in high enough doses...

         or lead poisoning
        Lead poisoning
        Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems...

      • ototoxic medications
        • analgesics:
          • aspirin
            Aspirin
            Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...

          • nonsteroidal anti-inflammatory drugs
        • antibiotics:
          • Ciprofloxacin
            Ciprofloxacin
            Ciprofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class.It is a second-generation fluoroquinolone antibacterial. It kills bacteria by interfering with the enzymes that cause DNA to rewind after being copied, which stops synthesis of DNA and of...

          • aminoglycosides, e.g., gentamicin
          • chloramphenicol
            Chloramphenicol
            Chloramphenicol is a bacteriostatic antimicrobial that became available in 1949. It is considered a prototypical broad-spectrum antibiotic, alongside the tetracyclines, and as it is both cheap and easy to manufacture it is frequently found as a drug of choice in the third world.Chloramphenicol is...

          • erythromycin
            Erythromycin
            Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...

          • tetracycline
          • tobramycin
          • vancomycin
            Vancomycin
            Vancomycin INN is a glycopeptide antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. It has traditionally been reserved as a drug of "last resort", used only after treatment with other antibiotics had failed, although the emergence of...

          • doxycycline
            Doxycycline
            Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...

             (Vibramycin)
        • chemotherapy
          Chemotherapy
          Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

           and antiviral drug
          Antiviral drug
          Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...

          s:
          • bleomycin
            Bleomycin
            Bleomycin is a glycopeptide antibiotic produced by the bacterium Streptomyces verticillus. Bleomycin refers to a family of structurally related compounds. When used as an anticancer agent, the chemotherapeutical forms are primarily bleomycin A2 and B2. It works by causing breaks in DNA...

          • interferon
            Interferon
            Interferons are proteins made and released by host cells in response to the presence of pathogens—such as viruses, bacteria, or parasites—or tumor cells. They allow communication between cells to trigger the protective defenses of the immune system that eradicate pathogens or tumors.IFNs belong to...

          • pegylated interferon-alpha-2b
          • cisplatin
            Cisplatin
            Cisplatin, cisplatinum, or cis-diamminedichloroplatinum is a chemotherapy drug. It is used to treat various types of cancers, including sarcomas, some carcinomas , lymphomas, and germ cell tumors...

          • mechlorethamine
          • methotrexate
            Methotrexate
            Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...

          • vincristine
            Vincristine
            Vincristine , formally known as leurocristine, sometimes abbreviated "VCR", is a vinca alkaloid from the Catharanthus roseus , formerly Vinca rosea and hence its name. It is a mitotic inhibitor, and is used in cancer chemotherapy.-Mechanism:Tubulin is a structural protein that polymerizes to...

        • loop diuretics:
          • bumetanide
            Bumetanide
            Bumetanide is a loop diuretic of the sulfamyl category to treat heart failure. It is often used in people in whom high doses of furosemide are ineffective. It is marketed by Hoffmann-La Roche. The main difference between the two substances is in bioavailability and pharmacodynamic potency...

          • ethacrynic acid
            Ethacrynic acid
            Etacrynic acid or ethacrynic acid , trade name Edecrin, is a loop diuretic used to treat high blood pressure and the swelling caused by diseases like congestive heart failure, liver failure, and kidney failure....

          • furosemide
            Furosemide
            Furosemide or frusemide is a loop diuretic used in the treatment of congestive heart failure and edema. It is most commonly marketed by Sanofi-Aventis under the brand name Lasix...

        • others:
          • chloroquine
            Chloroquine
            Chloroquine is a 4-aminoquinoline drug used in the treatment or prevention of malaria.-History:Chloroquine , N'--N,N-diethyl-pentane-1,4-diamine, was discovered in 1934 by Hans Andersag and co-workers at the Bayer laboratories who named it "Resochin". It was ignored for a decade because it was...

          • quinine
            Quinine
            Quinine is a natural white crystalline alkaloid having antipyretic , antimalarial, analgesic , anti-inflammatory properties and a bitter taste. It is a stereoisomer of quinidine which, unlike quinine, is an anti-arrhythmic...

          • antidepressants
          • varenicline (Champix)
          • naproxen
            Naproxen
            Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...

  • neurologic disorders:
    • chiari malformation
    • multiple sclerosis
      Multiple sclerosis
      Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...

    • head injury
      Head injury
      Head injury refers to trauma of the head. This may or may not include injury to the brain. However, the terms traumatic brain injury and head injury are often used interchangeably in medical literature....

      • skull fracture
        Skull fracture
        A skull fracture is a break in one or more of the bones in the skull usually occurring as a result of blunt force trauma. If the force of the impact is excessive the bone may fracture at or near the site of the impact...

      • closed head injury
      • whiplash
        Whiplash (medicine)
        Whiplash is a non-medical term describing a range of injuries to the neck caused by or related to a sudden distortion of the neck associated with extension. The term "whiplash" is a colloquialism...

         injury
      • temporomandibular joint disorder
        Temporomandibular joint disorder
        Temporomandibular joint disorder , or TMJ syndrome, is an umbrella term covering acute or chronic inflammation of the temporomandibular joint, which connects the mandible to the skull. The disorder and resultant dysfunction can result in significant pain and impairment...

      • giant cell arteritis

  • metabolic disorders:
    • thyroid disease
      Thyroid disease
      -Hyper- and hypofunction:Imbalance in production of thyroid hormones arises from dysfunction of the thyroid gland itself, the pituitary gland, which produces thyroid-stimulating hormone , or the hypothalamus, which regulates the pituitary gland via thyrotropin-releasing hormone . Concentrations of...

    • hyperlipidemia
      Hyperlipidemia
      Hyperlipidemia, hyperlipoproteinemia, or hyperlipidaemia is the condition of abnormally elevated levels of any or all lipids and/or lipoproteins in the blood...

    • vitamin B 12
      Vitamin B12
      Vitamin B12, vitamin B12 or vitamin B-12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins...

       deficiency
    • iron deficiency anemia
      Iron deficiency anemia
      Iron-deficiency anemia is a common anemia that occurs when iron loss occurs, and/or the dietary intake or absorption of iron is insufficient...


  • psychiatric disorders:
    • depression
      Clinical depression
      Major depressive disorder is a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities...

    • anxiety
      Anxiety
      Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...


  • other causes:
    • tension myositis syndrome
      Tension myositis syndrome
      Tension myositis syndrome , also known as tension myoneural syndrome, is a name given by John E. Sarno to a condition he describes as characterized by psychosomatic musculoskeletal and nerve symptoms, most notably back pain...

    • fibromyalgia
      Fibromyalgia
      Fibromyalgia is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure. It is an example of a diagnosis of exclusion...

    • vasculitis
      Vasculitis
      Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...

    • hypertonia
      Hypertonia
      Hypertonia a condition marked by an abnormal increase in muscle tension and a reduced ability of a muscle to stretch. It is caused by lesions to upper motor neurons in the central nervous system, which carry information from the central nervous system to the muscles and control posture, muscle...

       (muscle tension)
    • thoracic outlet syndrome
      Thoracic outlet syndrome
      Thoracic outlet syndrome is a syndrome involving compression at the superior thoracic outlet involving compression of a neurovascular bundle passing between the anterior scalene and middle scalene...

    • Lyme disease
      Lyme disease
      Lyme disease, or Lyme borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi sensu stricto is the main cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii cause most...

    • hypnagogia
      Hypnagogia
      Hypnagogia is the transitional state between wakefulness and sleep , originally coined in adjectival form as "hypnagogic" by Alfred Maury....

    • sleep paralysis
      Sleep paralysis
      Sleep paralysis is paralysis associated with sleep that may occur in healthy persons or may be associated with narcolepsy, cataplexy, and hypnagogic hallucinations. The pathophysiology of this condition is closely related to the normal hypotonia that occurs during REM sleep. When considered to be a...

    • glomus tympanicum tumor
      Glomus tumor
      A glomus tumor is a rare benign neoplasm arising from the glomus body...

    • anthrax vaccines which contain the anthrax protective antigen
    • Some psychedelic drugs can produce temporary tinnitus-like symptoms as a side effect
      • 5-MeO-DET
        5-MeO-DET
        5-MeO-DET or 5-methoxy-N,N-diethyltryptamine is a hallucinogenic tryptamine.-Effects:Low dosages are reported to produce a relaxing body high and mild entheogenic effects. Shulgin reports in TiHKAL that higher dosages can produce very unpleasant reactions.-External links:**...

      • diisopropyltryptamine (DiPT)
    • benzodiazepine withdrawal
    • nasal congestion
      Nasal congestion
      Nasal congestion is the blockage of the nasal passages usually due to membranes lining the nose becoming swollen from inflamed blood vessels. It is also known as nasal blockage, nasal obstruction, blocked nose, stuffy nose, or stuffed up nose.Nasal congestion has many causes and can range from a...

    • intracranial hyper or hypotension caused by for example, Encephalitis or a cerebrospinal fluid leak

Pathophysiology


One of the possible mechanisms relies on otoacoustic emissions. The inner ear
Inner ear
The inner ear is the innermost part of the vertebrate ear. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:...

 contains thousands of minute hairs, called stereocilia, which vibrate in response to sound waves, and cells which convert neural signals into tension on the vibrating basement membrane. The sensing cells are connected with the vibratory cells through a neural feedback loop, whose gain is regulated by the brain. This loop is normally adjusted just below onset of self-oscillation, which gives the ear spectacular sensitivity and selectivity. If something changes, it is easy for the delicate adjustment to cross the barrier of oscillation, and tinnitus results. Listening to loud music kills hair cells, and studies have shown as hair cells are lost, different neurons are activated, activating auditory parts of the brain and giving the perception of sound.

Another possible mechanism underlying tinnitus is damage to the receptor cells. Although receptor cells can be regenerated from the adjacent supporting Deiters cells after injury in birds, reptiles, and amphibians, in mammals it is believed they can be produced only during embryogenesis
Embryogenesis
Embryogenesis is the process by which the embryo is formed and develops, until it develops into a fetus.Embryogenesis starts with the fertilization of the ovum by sperm. The fertilized ovum is referred to as a zygote...

. Although mammalian Deiters cells reproduce and position themselves appropriately for regeneration, they have not been observed to transdifferentiate
Transdifferentiation
Transdifferentiation in biology takes place when a non-stem cell transforms into a different type of cell, or when an already differentiated stem cell creates cells outside its already established differentiation path...

 into receptor cells except in tissue culture experiments. Therefore, if these hairs become damaged, through prolonged exposure to excessive sound levels, for instance, then deafness to certain frequencies results. In tinnitus, they may relay information that an externally audible sound is present at a certain frequency when it is not.

The mechanisms of subjective tinnitus are often obscure. While it is not surprising that direct trauma to the inner ear can cause tinnitus, other apparent causes (e.g., temporomandibular joint disorder
Temporomandibular joint disorder
Temporomandibular joint disorder , or TMJ syndrome, is an umbrella term covering acute or chronic inflammation of the temporomandibular joint, which connects the mandible to the skull. The disorder and resultant dysfunction can result in significant pain and impairment...

 (TMJD or TMD) and dental disorders) are difficult to explain. Research has proposed there are two distinct categories of subjective tinnitus: otic tinnitus, caused by disorders of the inner ear or the acoustic nerve, and somatic tinnitus, caused by disorders outside the ear and nerve, but still within the head or neck. It is further hypothesized somatic tinnitus may be due to "central crosstalk" within the brain, as certain head and neck nerves enter the brain near regions known to be involved in hearing.

Studies by researchers at the University of Western Australia
University of Western Australia
The University of Western Australia was established by an Act of the Western Australian Parliament in February 1911, and began teaching students for the first time in 1913. It is the oldest university in the state of Western Australia and the only university in the state to be a member of the...

 suggest tinnitus is caused by increased neural activity in the auditory brainstem where the brain processes sounds, causing some auditory nerve cells to become overexcited. The basis of this theory is most people with tinnitus also have hearing loss, and the frequencies they cannot hear are similar to the subjective frequencies of their tinnitus. Models of hearing loss and the brain support the idea a homeostatic response of central dorsal cochlear nucleus
Dorsal cochlear nucleus
The dorsal cochlear nucleus , is a cortex-like structure on the dorso-lateral surface of the brainstem...

 neurons could result in them being hyperactive in a compensation process to the loss of hearing input. This, in turn, is related to changes in the genes involved in regulating the activity of those nerve cells. This proposed mechanism suggests possible treatments for the condition, involving the normalization or suppression of overactive neural activity through electrical or chemical means.

While most discussions of tinnitus tend to emphasize physical mechanisms, there is strong evidence the level of an individual's awareness of his or her tinnitus can be stress-related, and so should be addressed by improving the state of the nervous system generally, using gradual, unobtrusive, long-term treatments.

Since some tinnitus mimics electronic sounds, some recent research is focusing on electronics, the use of cell phones, and other modern electronic devices as possible causes.

Diagnosis


The basis of quantitatively measuring tinnitus relies on the brain’s tendency to select out only the loudest sounds heard. Based on this tendency, the amplitude of a patient's tinnitus can be measured by playing sample sounds of known amplitude and asking the patient which he or she hears. The volume of the tinnitus will always be equal to or less than that of the sample noises heard by the patient. This method works very well to gauge objective tinnitus (see above.) For example: if a patient has a pulsatile paraganglioma
Paraganglioma
A paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites . About 97% are benign and cured by surgical removal; the remaining 3% are malignant because they are able to produce distant metastases...

 in his ear, he will not be able to hear the blood flow through the tumor when the sample noise is 5 decibels louder than the noise produced by the blood. As sound amplitude is gradually decreased, the tinnitus will become audible, and the level at which it does so provides an estimate of the amplitude of the objective tinnitus.

Objective tinnitus, however, is quite uncommon. Often patients with pulsatile tumors will report other coexistent sounds, distinct from the pulsatile noise, that will persist even after their tumor has been removed. This is generally subjective tinnitus, which, unlike the objective form, cannot be tested by comparative methods.

If the attention of a subject is focused on a sample noise, he can often detect it at levels below 5 decibels, which would indicate his tinnitus would be almost impossible to hear . Conversely, if the same test subject is told to focus only on the tinnitus, he will report hearing the sound even when test noises exceed 70 decibels, making the tinnitus louder than a ringing phone. This quantification method suggests subjective tinnitus relates only to what the patient is attempting to hear . Whilst it is tempting to assume patients actively complaining about tinnitus have simply become obsessed with the noise, this is only partially true. The noises are often present in both quiet and noisy environments, and can become quite intrusive to their daily lives. The problem is involuntary; generally, complaining patients simply cannot override or ignore their tinnitus.

Subjective tinnitus may not always be correlated with ear malfunction or hearing loss. Even people with near-perfect hearing may still complain of it.

Measuring tinnitus with auditory evoked response


Tinnitus is the description of a noise inside a person’s head in the absence of auditory stimulation. The noise can be described in many different ways, but the most common description of the tinnitus is a pure tone sound. Tinnitus affects one third of adults at some time in their lives, whereas ten to fifteen percent are disturbed enough to seek medical evaluation About two million Americans are so seriously disturbed by tinnitus that they cannot function on a day-to-day basis. (American Tinnitus Association, 2010).

Tinnitus can be classified as either subjective or objective. Objective tinnitus can be detected by other people and is usually caused by myoclonus
Myoclonus
Myoclonus is brief, involuntary twitching of a muscle or a group of muscles. It describes a medical sign and, generally, is not a diagnosis of a disease. Brief twitches are perfectly normal. The myoclonic twitches are usually caused by sudden muscle contractions; they also can result from brief...

 or a vascular condition. Subjective tinnitus can only heard by the affected person and is caused by otology
Otology
Otology is a branch of biomedicine which studies normal and pathological anatomy and physiology of the ear as well as its diseases, diagnosis and treatment....

, neurology, infection or drugs. A frequent cause of subjective tinnitus is noise exposure which damages hair cells in the inner ear causing tinnitus. Tinnitus can be associated with many emotions. It is best illustrated by Jastreboff’s Neurophysiological model.

The “Edge Effect” theory has been described by many researchers throughout the literature when discussing tinnitus. As hair cells are loss or damaged, afferent neurons generate auditory sensations at frequencies near the impaired region. This theory possibly explains why tinnitus can be associated with a reflection of hearing loss and why tinnitus can be persistent.

Some researchers believe that spontaneous otoacoustic emissions (SOAEs) may be associated with tinnitus. Processes in the cochlea can cause self oscillation that is perceived as tinnitus, but most studies found that the two phenomena are not related. The evaluation of SOAEs and tinnitus was based on pitch matching and researchers concluded that not enough evidence could be seen to make the conclusion. When the researchers used two specific criteria to evaluate the results, researchers found SOAEs and tinnitus to be related in 2.42% of subjects.

In 2010, Qasem compared the differences in outer hair cell function in normal hearing patients with and without tinnitus. Distortion product OAEs (DPOAEs) were measured and results showed significant differences between groups at all DPOAE frequencies tested. Researchers concluded that decreased DPOAE amplitude can be seen in tinnitus patients due to the association between tinnitus and reduced outer hair cell movement. This study illustrates that the outer hair cells are related to tinnitus.

Moller studied the effects of tinnitus in relation to compound action potentials (CAP) in 1992. Researchers recorded compound action potential components N1 and N2 and found that the latencies of the responses in the tinnitus patients were similar to patients with no tinnitus. This study concludes that tinnitus effects can not be observed in CAP.
The effects of tinnitus on auditory brainstem response (ABR) measures have also been evaluated by many researchers. Auditory pathway plays a role in the emotional and physiological response to tinnitus. Research has shown abnormal ABR results (interwave latency delays) in patients with tinnitus. In 2008, Kehrle used ABR testing to evaluate the auditory nerve and brainstem function of tinnitus patients with normal hearing. Results showed delayed wave latencies and interpeak latencies between the tinnitus and non tinnitus patients. Researchers concluded that latency prolongations of wave I and lengthening of III-V IPL found in this study confirmed the findings in previous research. Maurizi in 1985 used ABRs to evaluate the auditory pathway in patients with tinnitus and concluded that patients with tinnitus had abnormal ABR recordings. Peripheral tinnitus was reduced with residual inhibition and recordings returned to normal. However, this method is not valid for all tinnitus patients due to the many different causes of tinnitus. Gerken in 2001 evaluated the influence of tinnitus on auditory evoked potentials. Results showed delayed ABR wave VII latencies in the tinnitus group and about half of the tinnitus patients had MLR amplitudes that were significantly greater than the control group mean. Researchers concluded the latency differences for wave VII only adds more diversity to research findings and should be included in future research. Large MLR waves seen in the tinnitus group may be caused by unknown smaller factors not accounted for in the study.

Tinnitus and auditory evoked cortical potentials have also been studied. It is important to evaluate the primary auditory cortex in relation to Jastrebroff’s model. “ALRs reflect stimulus properties as well as attention and the psychological state of the subjects, both of which are presumed to contribute to tinnitus” -Kadner (2002). Low and colleagues in 2008 concluded that ALRs can be used to evaluate the effectiveness of therapies used to alleviate tinnitus.

Tinnitus has also been studied in relation to event related potentials. In 1991, Shiraishi and colleagues found that the contingent negative variation (CNV) amplitude was significantly enlarged in tinnitus patients. They also found no effect on the latency and amplitude of the N100 and P300 responses. Attias in 1993, found that the amplitudes of N1, P2, and P3 were reduced, P3 latencies delayed, and N1 and N2 had delayed latencies to non-target stimuli.

In 2008, Delb conducted a study that evaluated tinnitus patients with high and low tinnitus related distress and how they differ in respect to focus levels on the tinnitus. Researchers concluded that patients with different levels of distress have differences in their ability to shift attention.

Elbert in 2004 studied the relation between tinnitus and mismatched negativity (MMN). Researchers recorded MMN potentials at stimulus levels at the edge frequency of the patient’s tinnitus and found differences in the recordings. This finding can be applied to tinnitus treatments to monitor progress and show effectiveness.

Tinnitus and long latency auditory evoked potentials (LLAEPs) have also been researched quite frequently. Alterations of LLAEPs have been seen in individuals with tinnitus and indicate problems in the auditory pathway in the cortex which can be concluded by increased latency values. In 2010, Santos Filha measured LLAEP potentials of tinnitus patients with a history of noise exposure. Researchers concluded that LLAEP shifts occur more often in individuals with tinnitus when compared to the control group.

In conclusion, tinnitus can be evaluated with most auditory evoked potentials; however results may be inconsistent. Results must be compared to age and hearing matched control subjects to be reliable. This inconsistently reported may be due to many reasons: differences in the origin of the tinnitus, ABR recording methods, and selection criteria of control groups. Since research shows conflicting evidence, more research on the relationship between tinnitus and auditory evoked potentials should be carried out before these measurements are used clinically.

Prevention


Tinnitus and hearing loss can be permanent conditions. If a ringing in the ears is audible following lengthy exposure to a source of loud noise, such as a music concert or an industrial workplace, it means lasting damage may already have occurred.

Prolonged exposure to sound or noise levels as low as 70 dB
Decibel
The decibel is a logarithmic unit that indicates the ratio of a physical quantity relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities...

 can result in damage to hearing (see noise health effects
Noise health effects
Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance and sleep disturbance. Changes in the immune system and birth defects have been attributed to noise exposure...

). For musicians and DJs, special musicians' earplugs play an important role in preventing tinnitus; they can lower the volume of the music without distorting the sound and can prevent tinnitus from developing in later years. For anyone using loud electrical appliances, such as hair dryers or vacuum cleaners, or who work in noisy environments such as building sites, where earmuffs
Earmuffs
Earmuffs are objects designed to cover a person's ears for protection. They consist of a thermoplastic or metal head-band, that fits over the top of the head, and a pad at each end, to cover the external ears....

 are impractical, earplugs are also helpful in reducing noise exposure. This is also the case for while riding motorcycles, mopeds etc. While operating lawn mowers, hammer drills, grinders, and similar, earmuffs may be more appropriate for hearing protection.

It is also important to check medications for potential ototoxicity
Ototoxicity
Ototoxicity is damage to the ear , specifically the cochlea or auditory nerve and sometimes the vestibular system, by a toxin. It is commonly medication-induced; ototoxic drugs include antibiotics such as the aminoglycoside gentamicin, loop diuretics such as furosemide, and platinum-based...

. Ototoxicity of multiple medicines can have a cumulative effect, and can greatly increase the damage done by noise. If ototoxic medications must be administered, close attention by the physician to prescription details, such as dose and dosage interval, can reduce the damage done.

Treatment


Many treatments for tinnitus have been claimed, with varying degrees of statistical reliability:

Objective tinnitus:
  • Gamma knife radiosurgery
    Radiosurgery
    Radiosurgery is a medical procedure that allows non-invasive treatment of benign and malignant tumors. It is also known as stereotactic radiotherapy, when used to target lesions in the brain, and stereotactic body radiotherapy when used to target lesions in the body...

     (glomus jugulare)
  • Shielding of cochlea by teflon implant
  • Botulinum toxin
    Botulinum toxin
    Botulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...

     (palatal tremor)
  • Clearing ear canal (in the case of earwax plug)
  • Using a neurostimulator
    Neurostimulator
    In medical technology a neurostimulator, also called an implanted pulse generator is a battery powered device designed to deliver electrical stimulation to the brain.-Applications and use:...



Subjective tinnitus:
  • Drugs and nutrients
    • Melatonin
      Melatonin
      Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...

       (especially for those with sleep disturbance)
    • Lidocaine
      Lidocaine
      Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...

       injection into the inner ear was found to suppress the tinnitus for 20 minutes, according to a Swedish study.
    • Older benzodiazepines, e.g. diazepam
      Diazepam
      Diazepam , first marketed as Valium by Hoffmann-La Roche is a benzodiazepine drug. Diazepam is also marketed in Australia as Antenex. It is commonly used for treating anxiety, insomnia, seizures including status epilepticus, muscle spasms , restless legs syndrome, alcohol withdrawal,...

      , are sometimes used for tinnitus; however, there are significant risks associated with the long-term use of benzodiazepines.
    • Tricyclics (amitriptyline
      Amitriptyline
      Amitriptyline is a tricyclic antidepressant . It is the most widely used TCA and has at least equal efficacy against depression as the newer class of SSRIs...

      , nortriptyline
      Nortriptyline
      Nortriptyline is a second-generation tricyclic antidepressant marketed as the hydrochloride salt under the trade names Sensoval, Aventyl, Pamelor, Norpress, Allegron, Noritren and Nortrilen. It is used in the treatment of major depression and childhood nocturnal enuresis...

      ) in small doses
    • Avoidance of caffeine
      Caffeine
      Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...

      , nicotine
      Nicotine
      Nicotine is an alkaloid found in the nightshade family of plants that constitutes approximately 0.6–3.0% of the dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves...

      , or salt
      Sodium chloride
      Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...

       can reduce symptoms, but, tinnitus can also be induced by reducing caffeine and/or quitting smoking.
    • The consumption of alcohol
      Ethanol
      Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

       has been found to both increase and decrease the severity of tinnitus. Therefore, alcohol's effect on the severity of tinnitus is dependent on the causes of the individual's affliction, and cannot be considered a treatment.
    • Zinc
      Zinc
      Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

       supplementation (where serum zinc deficiency is present)
    • Acamprosate
      Acamprosate
      Acamprosate, also known as N-acetyl homotaurine and by the brand name Campral, is a drug used for treating alcohol dependence.Acamprosate is thought to stabilize the chemical balance in the brain that would otherwise be disrupted by alcoholism, possibly by blocking glutamatergic...

    • Etidronate or sodium fluoride (otosclerosis)
    • Lignocaine or anticonvulsant
      Anticonvulsant
      The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

      s (usually in patients responsive to white noise masking)
    • Carbamazepine
      Carbamazepine
      Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder, as well as trigeminal neuralgia...

    • Sertraline
      Sertraline
      Sertraline hydrochloride is an antidepressant of the selective serotonin reuptake inhibitor class. It was introduced to the market by Pfizer in 1991. Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive–compulsive, panic, and social anxiety disorders in...

    • Vitamin
      Vitamin
      A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. In other words, an organic chemical compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Thus, the term is conditional both on...

       combinations (lipoflavonoid)
  • Electrical stimulation
    • Transcranial magnetic stimulation
      Transcranial magnetic stimulation
      Transcranial magnetic stimulation is a noninvasive method to cause depolarization or hyperpolarization in the neurons of the brain...

       or transcranial direct current stimulation
      Transcranial direct current stimulation
      Transcranial direct current stimulation is a form of neurostimulation which uses constant, low current delivered directly to the brain area of interest via small electrodes...

    • Transcutaneous electrical nerve stimulation
      Transcutaneous electrical nerve stimulation
      Transcutaneous electrical nerve stimulation is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes...

    • Direct stimulation of auditory cortex by implanted electrodes
    • Berthold Langguth, German neurologist, would apply an electric or magnetic current for stimulation over the head of the patient to reduce ringing sound. Dirk De Ridder, Belgian neurosurgeon, implanted electrodes to the brain of sufferers to normalise overactive neurons. Cambridge University scientists also found lidocaine
      Lidocaine
      Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...

      , an anaesthetic, reduces the sound in 2/3 of patients for 5 minutes, but it needs another drug to suppress its dangerous effects.
    • Vagus nerve stimulation
  • Surgery
    • Repair of the perilymph fistula
      Perilymph fistula
      A labyrinthine fistula is an abnormal opening in the bony capsule of the inner ear, resulting in leakage of the perilymph from the semicircular canals into the middle ear . This includes specifically a perilymph fistula , an abnormal connection between the fluid of the inner ear and the air-filled...

  • External sound
    • Low-pitched sound treatment has shown some positive, encouraging results.(UC, Irvine press release)
    • Tinnitus masker
      Tinnitus masker
      Tinnitus maskers are a range of devices based on simple white noise machines which are used to add natural or artificial sound into a tinnitus sufferer's environment in order to suppress or mask the perceived ringing....

       (white noise
      White noise
      White noise is a random signal with a flat power spectral density. In other words, the signal contains equal power within a fixed bandwidth at any center frequency...

      , or better 'shaped' or filtered noise)
    • Tinnitus retraining therapy
      Tinnitus retraining therapy
      Tinnitus retraining therapy is a form of habituation therapy designed to help people who suffer from tinnitus . TRT uses counselling to explain to the patient how a combination of tinnitus retraining and sound enrichment can end their negative reaction to the tinnitus sound, and then reduce and...

    • Auditive stimulation therapy (music therapy)
    • Auditive destimulation therapy (also called "notched music" therapy) uses individually designed music with the patients' favorite music altered to remove the musical tones that match the aural frequencies associated with their tinnitus. The removal of these tones alleviates the tinnitus by destimulating brain activity for these specific frequencies.
    • Compensation for lost frequencies by use of a hearing aid
      Hearing aid
      A hearing aid is an electroacoustic device which typically fits in or behind the wearer's ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as "ear trumpets" or "ear horns", were passive funnel-like amplification cones designed to gather sound energy and...

      .
    • Ultrasonic bone-conduction external acoustic stimulation
    • Avoidance of outside noise (exogenous tinnitus)
  • Psychological cognitive behavioral therapy

Prognosis


The prognosis of tinnitus depends on the type and severity of the cause.

For tinnitus due to acute acoustic trauma, approximately 35% of cases report subsiding tinnitus at three months after the trauma, with approximately 10% of these cases being the degree of complete disappearance of the tinnitus, as studied among young men having acquired tinnitus from gunshots.

Notable individuals



Notable individuals with tinnitus include:
  • Richard Attenborough
    Richard Attenborough
    Richard Samuel Attenborough, Baron Attenborough , CBE is a British actor, director, producer and entrepreneur. As director and producer he won two Academy Awards for the 1982 film Gandhi...

  • Igor Balis
    Igor Bališ
    Igor Bališ is a former Slovakian footballer who currently plays for the 4. liga club FC Horses Šúrovce. Bališ played for West Bromwich Albion in England. He has also appeared for Slovan Bratislava and Spartak Trnava, as well as the Slovakia national team.Bališ moved to Albion for £150,000 in...

  • Thomas Bangalter
    Thomas Bangalter
    Thomas Bangalter is a French electronic musician best known as a member of the French house music duo Daft Punk. He has also recorded and released music as a member of the trio Stardust, the duo Together, and as a solo artist including compositions for the film Irréversible.Thomas Bangalter owns a...

  • Jeff Beck
    Jeff Beck
    Geoffrey Arnold "Jeff" Beck is an English rock guitarist. He is one of three noted guitarists to have played with The Yardbirds...

  • Ludwig van Beethoven
    Ludwig van Beethoven
    Ludwig van Beethoven was a German composer and pianist. A crucial figure in the transition between the Classical and Romantic eras in Western art music, he remains one of the most famous and influential composers of all time.Born in Bonn, then the capital of the Electorate of Cologne and part of...

  • Bono
    Bono
    Paul David Hewson , most commonly known by his stage name Bono , is an Irish singer, musician, and humanitarian best known for being the main vocalist of the Dublin-based rock band U2. Bono was born and raised in Dublin, Ireland, and attended Mount Temple Comprehensive School where he met his...

  • Peter Brown
    Peter Brown (singer)
    Peter Brown is an artist, songwriter and record producer. He grew up in Palos Heights, another Chicago suburb. His mother, Virginia, was artistic and musically talented and gave Peter music lessons at a very young age. Peter’s father, Maurice, was an electronic engineer and unwittingly helped him...

  • Gerard Butler
    Gerard Butler
    Gerard James Butler is a Scottish actor who has appeared on film, stage, and television. A trained lawyer, Butler turned to acting in the mid-1990s with small roles in productions such as the James Bond film Tomorrow Never Dies , which he followed with steady work on television, most notably in...

  • Louis-Ferdinand Celine
    Louis-Ferdinand Céline
    Louis-Ferdinand Céline was the pen name of French writer and physician Louis-Ferdinand Destouches . Céline was chosen after his grandmother's first name. He is considered one of the most influential writers of the twentieth century, developing a new style of writing that modernized both French and...

  • Eric Clapton
    Eric Clapton
    Eric Patrick Clapton, CBE, is an English guitarist and singer-songwriter. Clapton is the only three-time inductee to the Rock and Roll Hall of Fame: once as a solo artist, and separately as a member of The Yardbirds and Cream. Clapton has been referred to as one of the most important and...

  • Graham Cole
    Graham Cole
    Graham Cole is an English actor.He is best known as PC Tony Stamp in the ITV police drama The Bill, a role he has played from 1984 until 2009. He had made previous uncredited appearances as an unnamed PC....

  • Phil Collins
    Phil Collins
    Philip David Charles "Phil" Collins, LVO is an English singer-songwriter, drummer, pianist and actor best known as a drummer and vocalist for British progressive rock group Genesis and as a solo artist....

  • Charles Darwin
    Charles Darwin
    Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

  • John Densmore
    John Densmore
    John Paul Densmore is an American musician and songwriter. He is best known as the drummer of the rock group The Doors.-Early life and The Doors:Born in Los Angeles, Densmore attended Santa Monica City College and Cal...

  • Al Di Meola
    Al Di Meola
    Al Di Meola is an acclaimed American jazz fusion and Latin guitarist, composer, and record producer of Italian origin. With a musical career that has spanned more than three decades, he has become respected as one of the most influential guitarists in jazz to date...

  • Danny Elfman
    Danny Elfman
    Daniel Robert "Danny" Elfman is an American composer, best known for scoring music for television and film. Up until 1995, he was the lead singer and songwriter in the rock band Oingo Boingo, a group he formed in 1976...

  • Till Fellner
    Till Fellner
    - Biography :Pianist Till Fellner was born in Vienna and studied at the Konservatorium der Stadt Wien with Helene Sedo-Stadler, and subsequently with Alfred Brendel, Meira Farkas, Oleg Maisenberg and Claus-Christian Schuster. He won first prize in the Clara Haskil International Piano Competition...

  • Paul Gilbert
    Paul Gilbert
    Paul Brandon Gilbert is an American guitarist. He is well known for his technical guitar work with Racer X and Mr...

  • Gary Glitter
    Gary Glitter
    Gary Glitter is an English former glam rock singer-songwriter and musician.Glitter first came to prominence in the glam rock era of the early 1970s...

  • Vincent van Gogh
    Vincent van Gogh
    Vincent Willem van Gogh , and used Brabant dialect in his writing; it is therefore likely that he himself pronounced his name with a Brabant accent: , with a voiced V and palatalized G and gh. In France, where much of his work was produced, it is...

  • Francisco de Goya
  • Charlie Haden
    Charlie Haden
    Charles Edward Haden is an American jazz musician. He is a double bassist, probably best known for his long association with saxophonist Ornette Coleman...

  • Ayumi Hamasaki
    Ayumi Hamasaki
    is a Japanese singer-songwriter, record producer, model, lyricist, and actress. Also called "Ayu" by her fans, Hamasaki has been dubbed the "Empress of Pop" because of her popularity and widespread influence in Japan and throughout Asia. Born and raised in Fukuoka, she moved to Tokyo at fourteen to...

  • James Hetfield
    James Hetfield
    James Alan Hetfield is the rhythm guitarist, co-founder, main songwriter, and lead vocalist for the American heavy metal band Metallica. Hetfield co-founded Metallica in October 1981 after answering a classified advertisement by drummer Lars Ulrich in the Los Angeles newspaper The Recycler,...

  • Adolf Hitler
    Adolf Hitler
    Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...

  • Howard Hughes
    Howard Hughes
    Howard Robard Hughes, Jr. was an American business magnate, investor, aviator, engineer, film producer, director, and philanthropist. He was one of the wealthiest people in the world...

  • Joey Jordison
    Joey Jordison
    Joey Jordison , is an American musician, songwriter, and record producer, best known for his work as the drummer for the nu metal band Slipknot. He grew up in Waukee, Iowa with his parents and two sisters, and was given his first drum kit at the age of 8...

  • Garrison Keillor
    Garrison Keillor
    Gary Edward "Garrison" Keillor is an American author, storyteller, humorist, and radio personality. He is known as host of the Minnesota Public Radio show A Prairie Home Companion Gary Edward "Garrison" Keillor (born August 7, 1942) is an American author, storyteller, humorist, and radio...

  • Myles Kennedy
    Myles Kennedy
    Myles Richard Kennedy is an American musician and singer-songwriter best known as the lead vocalist and rhythm guitarist of the rock band Alter Bridge, and as the lead vocalist in Slash's current solo project...

  • Steve Kilbey
    Steve Kilbey
    Steven John Kilbey is the lead singer-songwriter and bass guitarist for The Church, an Australian rock band. He is also a music producer, poet, and painter....

  • David Letterman
    David Letterman
    David Michael Letterman is an American television host and comedian. He hosts the late night television talk show, Late Show with David Letterman, broadcast on CBS. Letterman has been a fixture on late night television since the 1982 debut of Late Night with David Letterman on NBC...

  • Huey Lewis
    Huey Lewis
    Huey Lewis is an American musician, songwriter and occasional actor.Lewis sings lead and plays harmonica for his band Huey Lewis and the News, in addition to writing or co-writing many of the band's songs...

  • Rush Limbaugh
    Rush Limbaugh
    Rush Hudson Limbaugh III is an American radio talk show host, conservative political commentator, and an opinion leader in American conservatism. He hosts The Rush Limbaugh Show which is aired throughout the U.S. on Premiere Radio Networks and is the highest-rated talk-radio program in the United...

  • Martin Luther
    Martin Luther
    Martin Luther was a German priest, professor of theology and iconic figure of the Protestant Reformation. He strongly disputed the claim that freedom from God's punishment for sin could be purchased with money. He confronted indulgence salesman Johann Tetzel with his Ninety-Five Theses in 1517...

  • Steve Martin
    Steve Martin
    Stephen Glenn "Steve" Martin is an American actor, comedian, writer, playwright, producer, musician and composer....

  • Joseph Mawle
    Joseph Mawle
    -Biography:Mawle graduated from Bristol Old Vic Theatre School in 2002 in the same year he appeared in the Irish Hurling TV adverts for Guinness. He began work in the theatre prior to training at Bristol mainly for Box Clever Theatre Company and in his own production of 'Solo Hamlet'He landed his...

  • Stephin Merritt
    Stephin Merritt
    Stephin Merritt is an American singer-songwriter based in Los Angeles , best known as the principal singer and songwriter in the band The Magnetic Fields...

  • Michelangelo
    Michelangelo
    Michelangelo di Lodovico Buonarroti Simoni , commonly known as Michelangelo, was an Italian Renaissance painter, sculptor, architect, poet, and engineer who exerted an unparalleled influence on the development of Western art...

  • Roger Miller
    Roger Miller (rock musician)
    Roger Miller is an American singer, songwriter and multi-instrumentalist best known for co-founding the groups Mission of Burma and Alloy Orchestra.His main instruments are guitar and piano...

  • Moby
    Moby
    Richard Melville Hall , better known by his stage name Moby, is an American musician, DJ, and photographer. He is known mainly for his sample-based electronic music and his outspoken liberal political views, including his support of veganism and animal rights.Moby gained attention in the early...

  • Derek Mooney
    Derek Mooney
    Derek James Mooney is an Irish radio and television presenter, as well as a radio producer. He currently presents a weekday afternoon programme called Mooney on RTÉ Radio 1....

  • Leonard Nimoy
    Leonard Nimoy
    Leonard Simon Nimoy is an American actor, film director, poet, musician and photographer. Nimoy's most famous role is that of Spock in the original Star Trek series , multiple films, television and video game sequels....

  • Andy Partridge
    Andy Partridge
    Andrew John "Andy" Partridge is an English singer, songwriter, and guitarist. He has been known as Sir John Johns and Melchior and rose to fame as a founding member, guitarist and chief songwriter of the pop/new wave band, XTC. He lives in Swindon, Wiltshire, where he was raised.Partridge also...

  • Tim Powles
    Tim Powles
    Tim Powles is a music producer and artist originally from New Zealand, and though now an Australian resident, he is of English/Irish descent. Also known as timEbandit Powles, his main instrument and first love was the drum kit and tuned percussion. In the 70's he won a scholarship to join the New...

  • Tony Randall
    Tony Randall
    Tony Randall was a U.S. actor, comic, producer and director.-Early years:Randall was born Arthur Leonard Rosenberg to a Jewish family in Tulsa, Oklahoma, the son of Julia and Mogscha Rosenberg, an art and antiques dealer...

  • Ronald Reagan
    Ronald Reagan
    Ronald Wilson Reagan was the 40th President of the United States , the 33rd Governor of California and, prior to that, a radio, film and television actor....

  • Jimmy Savile
    Jimmy Savile
    Sir James Wilson Vincent Savile, OBE, KCSG was an English disc jockey, television presenter and media personality, best known for his BBC television show Jim'll Fix It, and for being the first and last presenter of the long-running BBC music chart show Top of the Pops...

  • Neal Schon
    Neal Schon
    Neal George Joseph Schon is an American rock guitarist, songwriter, and vocalist best known for his work with the band Journey. He is the only member to have recorded on all of Journey's albums...

  • Robert Schumann
    Robert Schumann
    Robert Schumann, sometimes known as Robert Alexander Schumann, was a German composer, aesthete and influential music critic. He is regarded as one of the greatest and most representative composers of the Romantic era....

  • William Shatner
    William Shatner
    William Alan Shatner is a Canadian actor, musician, recording artist, and author. He gained worldwide fame and became a cultural icon for his portrayal of James T...

  • Alan Shepard
    Alan Shepard
    Alan Bartlett Shepard, Jr. was an American naval aviator, test pilot, flag officer, and NASA astronaut who in 1961 became the second person, and the first American, in space. This Mercury flight was designed to enter space, but not to achieve orbit...

  • Paul Simon
    Paul Simon
    Paul Frederic Simon is an American singer-songwriter and guitarist.Simon is best known for his success, beginning in 1965, as part of the duo Simon & Garfunkel, with musical partner Art Garfunkel. Simon wrote most of the pair's songs, including three that reached number one on the US singles...

  • Bedřich Smetana
    Bedrich Smetana
    Bedřich Smetana was a Czech composer who pioneered the development of a musical style which became closely identified with his country's aspirations to independent statehood. He is thus widely regarded in his homeland as the father of Czech music...

  • Vivian Stanshall
    Vivian Stanshall
    Vivian Stanshall was an English singer-songwriter, painter, musician, author, poet and wit, best known for his work with the Bonzo Dog Doo-Dah Band, for his surreal exploration of the British upper classes in Sir Henry at Rawlinson End, and for narrating Mike Oldfield's Tubular Bells.-The great...

  • Jack Straw
    Jack Straw
    Jack Straw , British politician.Jack Straw may also refer to:* Jack Straw , English* "Jack Straw" , 1971 song by the Grateful Dead* Jack Straw by W...

  • Barbra Streisand
    Barbra Streisand
    Barbra Joan Streisand is an American singer, actress, film producer and director. She has won two Academy Awards, eight Grammy Awards, four Emmy Awards, a Special Tony Award, an American Film Institute award, a Peabody Award, and is one of the few entertainers who have won an Oscar, Emmy, Grammy,...

  • Peter Stringfellow
    Peter Stringfellow
    Peter James Stringfellow is an English nightclub owner.-Early life:Stringfellow was born on 17 October 1940 to Elsie and James William Stringfellow , a steelworker...

  • Tom Tancredo
    Tom Tancredo
    Thomas Gerard "Tom" Tancredo is an American politician from Colorado, who represented the state's sixth congressional district in the United States House of Representatives from 1999 to 2009, as a Republican...

  • Pete Townshend
    Pete Townshend
    Peter Dennis Blandford "Pete" Townshend is an English rock guitarist, vocalist, songwriter and author, known principally as the guitarist and songwriter for the rock group The Who, as well as for his own solo career...

  • Alex Trebek
    Alex Trebek
    George Alexander "Alex" Trebek is a Canadian American game show host who has been the host of the game show Jeopardy! since 1984, and prior to that, he hosted game shows such as Pitfall and High Rollers. He has appeared in numerous television series, usually as himself...

  • KT Tunstall
    KT Tunstall
    Kate Victoria "KT" Tunstall is a Scottish singer-songwriter and guitarist from St Andrews, Scotland. She broke into the public eye with a 2004 live solo performance of her song "Black Horse and the Cherry Tree" on Later... with Jools Holland...

  • Lars Ulrich
    Lars Ulrich
    Lars Ulrich is a Danish drummer, and one of the founding members of the American thrash metal band Metallica. He was born in Gentofte, Denmark to an upper-middle class family. A tennis player in his youth, Ulrich moved to Los Angeles, California at age sixteen to pursue his training; though rather...

  • Neil Young
    Neil Young
    Neil Percival Young, OC, OM is a Canadian singer-songwriter who is widely regarded as one of the most influential musicians of his generation...

  • Will.i.am
    Will.i.am
    William James Adams, Jr. , better known by his stage name will.i.am and occasionally by his other stage name Zuper Blahq, is an American rapper, musician, songwriter, singer, actor and producer...

  • Ville Valo
    Ville Valo
    Ville Hermanni Valo is a Finnish singer, songwriter and frontman of the Finnish rock band HIM. He has received the "Golden God" award in 2004 by the heavy metal magazine Metal Hammer. Valo has a baritone vocal range. Valo was ranked number 80 in Hit Paraders Top 100 Metal Vocalists of All Time...



See also



  • Absolute threshold of hearing
    Absolute threshold of hearing
    The absolute threshold of hearing is the minimum sound level of a pure tone that an average ear with normal hearing can hear with no other sound present. The absolute threshold relates to the sound that can just be heard by the organism...

  • Audiologist
  • Auditory system
    Auditory system
    The auditory system is the sensory system for the sense of hearing.- Outer ear :The folds of cartilage surrounding the ear canal are called the pinna...

  • Ear
    Ear
    The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....

  • Hearing impairment
    Hearing impairment
    -Definition:Deafness is the inability for the ear to interpret certain or all frequencies of sound.-Environmental Situations:Deafness can be caused by environmental situations such as noise, trauma, or other ear defections...

  • Hyperacusis
    Hyperacusis
    Hyperacusis is a health condition characterized by an over-sensitivity to certain frequency ranges of sound...

  • Ménière's disease
    Ménière's disease
    Ménière's disease is a disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterized by episodes of vertigo and tinnitus and progressive hearing loss, usually in one ear. It is named after the French physician Prosper Ménière, who, in an article published...

  • Noise health effects
    Noise health effects
    Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance and sleep disturbance. Changes in the immune system and birth defects have been attributed to noise exposure...

  • Ringxiety
    Ringxiety
    Phantom rings are the sensation and false belief that one can hear one's mobile phone ringing or feel it vibrating, when in fact the telephone is not doing so.Other terms for this concept include ringxiety and fauxcellarm...

  • Tinnitus masker
    Tinnitus masker
    Tinnitus maskers are a range of devices based on simple white noise machines which are used to add natural or artificial sound into a tinnitus sufferer's environment in order to suppress or mask the perceived ringing....



External links


Further reading