Tinnitus | |
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Pronunciation | |
Specialty | Otorhinolaryngology, audiology, neurology |
Symptoms | Hearing sound when no external sound is present [1] |
Complications | Poor concentration, anxiety, depression [2] |
Usual onset | Gradual [3] |
Causes | Noise-induced hearing loss, ear infections, disease of the heart or blood vessels, Ménière's disease, brain tumors, inner ear tumors, emotional stress, traumatic brain injury, excessive earwax [2] [4] |
Diagnostic method | Based on symptoms, audiogram, neurological exam [1] [3] |
Treatment | Counseling, sound generators, hearing aids [2] [5] |
Frequency | ~12.5% [5] |
Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. [1] Nearly everyone experiences faint "normal tinnitus" in a completely quiet room; but this is of concern only if it is bothersome, interferes with normal hearing, or is associated with other problems. [6] The word tinnitus comes from the Latin tinnire, "to ring". [3] In some people, it interferes with concentration, and can be associated with anxiety and depression. [7] [8]
Tinnitus is usually associated with hearing loss and decreased comprehension of speech in noisy environments. [2] It is common, affecting about 10–15% of people. Most tolerate it well, and it is a significant problem in only 1–2% of people. [5] It can trigger a fight-or-flight response, as the brain may perceive it as dangerous and important. [9] [10] [11]
Rather than a disease, tinnitus is a symptom that may result from a variety of underlying causes and may be generated at any level of the auditory system as well as outside that system. The most common causes are hearing damage, noise-induced hearing loss, or age-related hearing loss, known as presbycusis. [2] Other causes include ear infections, disease of the heart or blood vessels, Ménière's disease, brain tumors, acoustic neuromas (tumors on the auditory nerves of the ear), migraines, temporomandibular joint disorders, exposure to certain medications, a previous head injury, and earwax. It can suddenly emerge during a period of emotional stress. [4] [3] [2] [12] [13] It is more common in those with depression. [3]
The diagnosis of tinnitus is usually based on a patient's description of the symptoms they are experiencing. [3] Such a diagnosis is commonly supported by an audiogram, and an otolaryngological and neurological examination. [1] [3] How much tinnitus interferes with a person's life may be quantified with questionnaires. [3] If certain problems are found, medical imaging, such as magnetic resonance imaging (MRI), may be performed. Other tests are suitable when tinnitus occurs with the same rhythm as the heartbeat. [3] Rarely, the sound may be heard by someone other than the patient by using a stethoscope, in which case it is known as "objective tinnitus." [3] Occasionally, spontaneous otoacoustic emissions, sounds produced normally by the inner ear, may result in tinnitus. [14]
Measures to prevent tinnitus include avoiding chronic or extended exposure to loud noise, and limiting exposure to ototoxic drugs and substances. [2] [15] If there is an underlying cause, treating that cause may lead to improvements. [3] Otherwise, typically, tinnitus management involves psychoeducation or counseling, such as talk therapy. [5] Sound generators or hearing aids may help. [2] No medication directly targets tinnitus.
Tinnitus is often described as ringing, but it may also sound like clicking, buzzing, hissing, or roaring. [4] It may be soft or loud, low- or high-pitched, and may seem to come from either one or both ears, or from the head itself. It may be intermittent or continuous. In some individuals, its intensity may be changed by shoulder, neck, head, tongue, jaw, or eye movements. [16]
Due to variations in study designs, data on the course of tinnitus shows few consistent results. Generally, prevalence increases with age in adults, and the ratings of annoyance decreases with duration[ clarification needed ]. [17] [18] [19]
Although it is an annoying condition to which most people adapt, persistent tinnitus may cause anxiety and depression in some people. [20] [21] Tinnitus annoyance is more strongly associated with the psychological condition of the person than the loudness or frequency range of the perceived sound. [22] [23] Psychological problems such as depression, anxiety, sleep disturbances, and concentration difficulties are common in those with strongly annoying tinnitus. [24] [25] 45% of people with tinnitus have an anxiety disorder at some time in their lives. [26]
Psychological research has focused on the tinnitus distress reaction to account for differences in tinnitus severity. [24] [27] [28] [29] The research indicates that conditioning at the initial perception of tinnitus linked it with negative emotions, such as fear and anxiety. [30]
Commonly tinnitus is classified into "subjective and objective tinnitus". [3] Tinnitus is usually subjective, meaning that the sounds the person hears are not detectable by means currently available to physicians and hearing technicians. [3] Subjective tinnitus has also been called "tinnitus aurium", "non-auditory", or "non-vibratory" tinnitus. In rare cases, tinnitus can be heard by someone else using a stethoscope. Even more rarely, in some cases it can be measured as a spontaneous otoacoustic emission (SOAE) in the ear canal. This is classified as objective tinnitus, [3] also called "pseudo-tinnitus" or "vibratory" tinnitus.
Subjective tinnitus is the most frequent type. It can have many causes, but most commonly it results from hearing loss. When it is caused by disorders of the inner ear or auditory nerve, it can be called "otic" (from the Greek word for ear). [31] These otological or neurological disorders include those triggered by infections, drugs, or trauma. [32] A frequent cause is traumatic noise exposure that damages hair cells in the inner ear.[ citation needed ]. Some evidence suggests that long-term exposure to noise pollution from heavy traffic may increase the risk of developing tinnitus. [33]
When there does not seem to be a connection with a disorder of the inner ear or auditory nerve, tinnitus can be called "non-otic". In 30% of cases, tinnitus is influenced by the somatosensory system; for instance, people can increase or decrease their tinnitus by moving their face, head, jaw, or neck. [34] This type is called somatic or craniocervical tinnitus, since it is only head or neck movements that have an effect. [31]
Some tinnitus may be caused by neuroplastic changes in the central auditory pathway. In this theory, the disturbance of sensory input caused by hearing loss results in such changes [35] as a homeostatic response of neurons in the central auditory system, causing tinnitus. [36] When some frequencies of sound are lost to hearing loss, the auditory system compensates by amplifying those frequencies, eventually producing sound sensations at those frequencies constantly even when there is no corresponding external sound.
The most common cause of tinnitus is hearing loss. Hearing loss may have many different causes, but among those with tinnitus, the major cause is cochlear injury. [35]
In many cases no underlying cause is identified. [2] [37]
Ototoxic drugs also may cause subjective tinnitus, as they may cause hearing loss, [15] or increase the damage done by exposure to loud noise. [38] This damage may occur even at doses not considered ototoxic. [39] More than 260 medications have been reported to cause tinnitus as a side effect. [40]
Tinnitus can also occur from the discontinuation of therapeutic doses of benzodiazepines. It can sometimes be a protracted symptom of benzodiazepine withdrawal and may persist for many months. [41] [42] Medications such as bupropion may also cause tinnitus. [43]
Factors associated with tinnitus include: [44]
A specific type of tinnitus, objective tinnitus, is characterized by hearing the sounds of one's own muscle contractions or pulse, typically a result of sounds that have been created by the movement of jaw muscles or sounds related to blood flow in the neck or face. [49] It is sometimes caused by an involuntary twitching of a muscle or a group of muscles (myoclonus) or by a vascular condition. In some cases, tinnitus is generated by muscle spasms around the middle ear. [49]
Spontaneous otoacoustic emissions (SOAEs)—faint high-frequency tones that are produced in the inner ear and can be measured in the ear canal with a sensitive microphone—may also cause tinnitus. [14] About 8% of those with SOAEs and tinnitus have SOAE-linked tinnitus,[ need quotation to verify ] while the percentage of all cases of tinnitus caused by SOAEs is estimated at 4%. [14]
Children may be subject to pulsatile or continuous tinnitus, involving anomalies and variants of the vascular parts [50] affecting the middle/inner ear structures. CT scans may be used to check the integrity of the structures, and MR scans can evaluate nerves and potential masses or malformations. Early diagnosis can prevent long-term impairments to development. [51]
Some people experience a sound that beats in time with their pulse, known as pulsatile tinnitus or vascular tinnitus. [52] Pulsatile tinnitus is usually objective in nature, resulting from altered blood flow or increased blood turbulence near the ear, such as from atherosclerosis or venous hum, [53] but it can also arise as a subjective phenomenon from an increased awareness of blood flow in the ear. [52]
The differential diagnosis for pulsatile tinnitus is wide and includes vascular etiologies, tumors, disorders of the middle ear or inner ear, and other intracranial pathologies. [54] Vascular causes of pulsatile tinnitus include venous causes (e.g., high riding or dehiscent jugular bulb, sigmoid sinus diverticulum), arterial causes (e.g., cervical atherosclerosis, potentially life-threatening conditions such as carotid artery aneurysm [55] or carotid artery dissection), or dural arteriovenous fistula or arteriovenous malformations. [56] Pulsatile tinnitus may also indicate vasculitis, or more specifically, giant cell arteritis. Pulsatile tinnitus may also be caused by tumors such as paragangliomas (e.g., glomus tympanicum, glomus jugulare) or hemangiomas (e.g., facial nerve or cavernous). Middle ear causes of pulsatile tinnitus include patulous eustachian tube, otosclerosis, or middle ear myoclonus (e.g., stapedial or tensor tympani myoclonus). The most common inner ear cause of pulsatile tinnitus is superior semicircular canal dehiscence. [57] Pulsatile tinnitus may also indicate idiopathic intracranial hypertension. [58] Pulsatile tinnitus can be a symptom of intracranial vascular abnormalities and should be evaluated for irregular noises of blood flow (bruits). [59]
Tinnitus may be 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 that many with tinnitus also have hearing loss. [60]
Three reviews in 2016 emphasized the large range and possible combinations of pathologies involved in tinnitus, which result in a great variety of symptoms and specifically adapted therapies. [61] [62] [63] [64]
The diagnostic approach is based on a history of the condition and an examination of the head, neck, and neurological system. [37] Typically an audiogram is done, and occasionally medical imaging or electronystagmography. [37] Treatable conditions may include middle ear infection, acoustic neuroma, concussion, and otosclerosis. [65]
Evaluation of tinnitus can include a hearing test (audiogram), measurement of acoustic parameters of the tinnitus like pitch and loudness, and psychological assessment of comorbid conditions like depression, anxiety, and stress that are associated with severity of the tinnitus.[ citation needed ]
One definition of tinnitus, in contrast to normal ear noise experience, is that tinnitus lasts five minutes at least twice a week. [66] However, people with tinnitus often experience the noise more frequently than this. Tinnitus can be present constantly or intermittently. Some people with constant tinnitus might not be aware of it all the time, but only, for example, during the night when there is less environmental noise to mask it. Chronic tinnitus can be defined as tinnitus with a duration of six months or more. [67]
Since most people with tinnitus also have hearing loss, a pure tone hearing test resulting in an audiogram may help diagnose a cause. An audiogram may also facilitate fitting of a hearing aid in those cases where hearing loss is significant. The pitch of tinnitus is often in the range of the hearing loss.
Acoustic qualification of tinnitus includes measurement of several acoustic parameters like frequency in cases of monotone tinnitus or frequency range and bandwidth in cases of narrow band noise tinnitus, loudness in dB above hearing threshold at the indicated frequency, mixing-point, and minimum masking level. [68] In most cases, tinnitus pitch or frequency range is between 5 kHz and 10 kHz, [69] and loudness between 5 and 15 dB above the hearing threshold. [70]
Another relevant parameter of tinnitus is residual inhibition: the temporary suppression or disappearance of tinnitus following a period of masking. The degree of residual inhibition may indicate how effective tinnitus maskers would be as treatment. [71] [72]
An assessment of hyperacusis, a frequent accompaniment of tinnitus, [73] may also be made. [74] Hyperacusis is related to negative reactions to sound and can take many forms. One parameter that can be measured 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 loudness discomfort level. A compressed dynamic range over a particular frequency range can be associated with 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. [75] [76]
Tinnitus is often rated on a scale from "slight" to "severe" according to the effects it has, such as interference with sleep, quiet activities, and normal daily activities. [77]
Assessment of psychological processes related to tinnitus involves measurement of tinnitus severity and distress, as measured subjectively by validated self-report tinnitus questionnaires. [24] Such questionnaires measure the degree of psychological distress and handicap associated with tinnitus, including effects on hearing, lifestyle, health, and emotional functioning. [78] [79] [80] A broader assessment of general functioning, such as levels of anxiety, depression, stress, life stressors, and sleep difficulties, is also important in the assessment of tinnitus due to higher risk of negative well-being across these areas, which may be affected by or exacerbate the tinnitus symptoms. [81] Current assessment measures aim to identify levels of distress and interference, coping responses, and perceptions of tinnitus to inform treatment and monitor progress. However, wide variability, inconsistencies, and lack of consensus regarding assessment methodology are evidenced in the literature, limiting comparison of treatment effectiveness. [82] Developed to guide diagnosis or classify severity, most tinnitus questionnaires have been shown to be treatment-sensitive outcome measures. [83]
If examination reveals a bruit (sound due to turbulent blood flow), imaging studies such as transcranial doppler (TCD) or magnetic resonance angiography (MRA) should be performed. [84] [85] [86]
Other potential sources of the sounds normally associated with tinnitus should be ruled out. For instance, two recognized sources of 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 hear objectively audible high-pitched transmission frequencies that sound similar to tinnitus. [87] [88]
Prolonged exposure to loud sound or noise levels can lead to tinnitus. [89] Custom made ear plugs or other measures can help with prevention. Employers may use hearing loss prevention programs to help educate and prevent dangerous levels of exposure to noise. Government organizations set regulations to ensure employees, if following the protocol, should have minimal risk to permanent damage to their hearing. [90]
Certain groups are advised to wear ear plugs to avoid the risk of tinnitus, such as that caused by overexposure to loud noises like wind noise for motorcycle riders. [91] This includes military personnel, [38] musicians, [92] DJs, [93] agricultural workers, [94] and construction workers [95] as people in those occupations are at a greater risk compared to the general population.
Several medicines have ototoxic effects, which can have a cumulative effect that increases the damage done by noise. [38] 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. [15] [96] [97] [98]
If a specific underlying cause is determined, treating it may lead to improvements. [3] Otherwise, the primary treatment for tinnitus is talk therapy, [5] sound therapy, or hearing aids. There are no effective drugs that treat tinnitus. [3] [99] [100]
The best-supported treatment for tinnitus is cognitive behavioral therapy (CBT). [5] [83] [101] It decreases the stress those with tinnitus feel. [102] This appears to be independent of any effect on depression or anxiety. [101] Acceptance and commitment therapy (ACT) also shows promise in the treatment of tinnitus. [103] Relaxation techniques may also help. [3] A clinical protocol called Progressive Tinnitus Management has been developed by the United States Department of Veterans Affairs. [104]
The application of sound therapy by either hearing aids or tinnitus maskers may help the brain ignore the specific tinnitus frequency. Although these methods are poorly supported by evidence, there are no negative effects. [3] [105] [106] There are several approaches for tinnitus sound therapy. The first is sound modification to compensate for the individual's hearing loss. The second is a signal spectrum notching[ jargon ] to eliminate energy close to the tinnitus frequency. [107] [108] There is some tentative evidence supporting tinnitus retraining therapy, which aims to reduce tinnitus-related neuronal activity. [3] [109] [108] An alternative tinnitus treatment uses mobile applications that include various methods including masking, sound therapy, and relaxation exercises. [110] [111] Such applications can work as a separate device or as a hearing aid control system. [112]
Neuromonics is another sound-based intervention. Its protocol follows the principle of systematic desensitization and involves a structured rehabilitation program lasting 12 months. Neuromonics therapy employs customized sound signals delivered through a device worn by the patient, which aims to target the specific frequency range associated with their tinnitus perception. [113]
Physical therapy for tinnitus focuses on relaxing jaw and neck muscles that may contribute to symptoms. Muscle tension, particularly in the jaw muscles like the masseter and medial pterygoid, can radiate to the ears, leading to somatic tinnitus. Specialized physical therapists use neuromuscular techniques to alleviate tension in these areas, which may reduce tinnitus intensity and associated pain in connected areas, such as the jaw, teeth, and ears [114] .
As of 2018 [update] there were no medications effective for idiopathic tinnitus. [3] [89] [115] There is not enough evidence to determine if antidepressants [116] or acamprosate are useful. [117] There are conflicting studies regarding the effectiveness of benzodiazepines for tinnitus. [3] [115] [118] [119] Usefulness of melatonin, as of 2015, is unclear. [120] It is unclear if anticonvulsants are useful for treating tinnitus. [3] [121] Steroid injections into the middle ear also do not seem to be effective. [122] [123] There is no evidence to suggest that the use of betahistine to treat tinnitus is effective. [124]
Botulinum toxin injection has succeeded in some of the rare cases of objective tinnitus from a palatal tremor. [125]
Caroverine is used in a few countries to treat tinnitus. [126] The evidence for its usefulness is very weak. [127]
In 2020, information about clinical trials indicated that bimodal neuromodulation may reduce the symptoms of tinnitus. It is a noninvasive technique that involves applying an electrical stimulus to the tongue while also administering sounds. [128] Equipment associated with the treatments is available through physicians. Studies with it and similar devices continue in several research centers.[ citation needed ]
In March 2023, the US Food and Drug Administration (FDA) approved Neuromod's Lenire device as a treatment option for tinnitus. [129] [130] [131] In June 2024, the US Department of Veterans Affairs (VA) announced it would begin offering the treatment to veterans with tinnitus, making it the first bimodal neuromodulation device to be awarded a Federal Supply Schedule (FSS) contract from the US Government. [131]
Some evidence supports neuromodulation techniques such as transcranial magnetic stimulation, [3] [132] transcranial direct current stimulation, and neurofeedback.
Ginkgo biloba does not appear to be effective. [115] [133] The American Academy of Otolaryngology recommends against taking melatonin or zinc supplements to relieve symptoms of tinnitus, and reported that evidence for the efficacy of many dietary supplements (such as lipoflavonoids, garlic, traditional Chinese/Korean herbal medicine, honeybee larvae, and various other vitamins and minerals, as well as homeopathic preparations) did not exist. [89] A 2016 Cochrane Review also concluded that evidence was not sufficient to support taking zinc supplements to reduce symptoms associated with tinnitus. [134]
While there is no cure, most people with tinnitus get used to it over time; for a minority, it remains a significant problem. [5]
Tinnitus affects 10–15% of people. [5] About a third of North Americans over 55 experience it. [135] It affects one third of adults at some time in their lives, whereas 10–15% are disturbed enough to seek medical evaluation. [136] 70 million people in Europe are estimated to have tinnitus. [137] [138]
Tinnitus is commonly thought of as a symptom of adulthood, and is often overlooked in children. Children with hearing loss have a high incidence of pediatric tinnitus, even though they do not express the condition or its effect on their lives. [139] [140] Children do not generally report tinnitus spontaneously and their complaints may not be taken seriously. [141] Among those who do complain, there is an increased likelihood of associated otological or neurological pathology such as migraine, juvenile Meniere's disease, or chronic suppurative otitis media. [142] Its reported prevalence varies from 12 to 36% in children with normal hearing thresholds, and up to 66% in children with a hearing loss. Approximately 3–10% of children have been reported to be troubled by tinnitus. [143]
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness.
Ménière's disease (MD) is a disease of the inner ear that is characterized by potentially severe and incapacitating episodes of vertigo, tinnitus, hearing loss, and a feeling of fullness in the ear. Typically, only one ear is affected initially, but over time, both ears may become involved. Episodes generally last from 20 minutes to a few hours. The time between episodes varies. The hearing loss and ringing in the ears can become constant over time.
A cochlear implant (CI) is a surgically implanted neuroprosthesis that provides a person who has moderate-to-profound sensorineural hearing loss with sound perception. With the help of therapy, cochlear implants may allow for improved speech understanding in both quiet and noisy environments. A CI bypasses acoustic hearing by direct electrical stimulation of the auditory nerve. Through everyday listening and auditory training, cochlear implants allow both children and adults to learn to interpret those signals as speech and sound.
The organ of Corti, or spiral organ, is the receptor organ for hearing and is located in the mammalian cochlea. This highly varied strip of epithelial cells allows for transduction of auditory signals into nerve impulses' action potential. Transduction occurs through vibrations of structures in the inner ear causing displacement of cochlear fluid and movement of hair cells at the organ of Corti to produce electrochemical signals.
Ototoxicity is the property of being toxic to the ear (oto-), specifically the cochlea or auditory nerve and sometimes the vestibular system, for example, as a side effect of a drug. The effects of ototoxicity can be reversible and temporary, or irreversible and permanent. It has been recognized since the 19th century. There are many well-known ototoxic drugs used in clinical situations, and they are prescribed, despite the risk of hearing disorders, for very serious health conditions. Ototoxic drugs include antibiotics, loop diuretics, and platinum-based chemotherapy agents. A number of nonsteroidal anti-inflammatory drugs (NSAIDS) have also been shown to be ototoxic. This can result in sensorineural hearing loss, dysequilibrium, or both. Some environmental and occupational chemicals have also been shown to affect the auditory system and interact with noise.
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear, sensory organ, or the vestibulocochlear nerve. SNHL accounts for about 90% of reported hearing loss. SNHL is usually permanent and can be mild, moderate, severe, profound, or total. Various other descriptors can be used depending on the shape of the audiogram, such as high frequency, low frequency, U-shaped, notched, peaked, or flat.
Hyperacusis is an increased sensitivity to sound and a low tolerance for environmental noise. Definitions of hyperacusis can vary significantly; it often revolves around damage to or dysfunction of the stapes bone, stapedius muscle or tensor tympani (eardrum). It is often categorized into four subtypes: loudness, pain, annoyance, and fear. It can be a highly debilitating hearing disorder.
Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult.
Tinnitus retraining therapy (TRT) is a form of habituation therapy designed to help people who experience tinnitus—a ringing, buzzing, hissing, or other sound heard when no external sound source is present. Two key components of TRT directly follow from the neurophysiological model of tinnitus: Directive counseling aims to help the sufferer reclassify tinnitus to a category of neutral signals, and sound therapy weakens tinnitus-related neuronal activity.
Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environmental stressors for humans, second only to air pollution. Elevated workplace or environmental noise can cause hearing impairment, tinnitus, hypertension, ischemic heart disease, annoyance, and sleep disturbance. Changes in the immune system and birth defects have been also attributed to noise exposure.
Noise-induced hearing loss (NIHL) is a hearing impairment resulting from exposure to loud sound. People may have a loss of perception of a narrow range of frequencies or impaired perception of sound including sensitivity to sound or ringing in the ears. When exposure to hazards such as noise occur at work and is associated with hearing loss, it is referred to as occupational hearing loss.
The semicircular canal dehiscence (SCD) is a category of rare neurotological diseases/disorders affecting the inner ears, which gathers the superior SCD, lateral SCD and posterior SCD. These SCDs induce SCD syndromes (SCDSs), which define specific sets of hearing and balance symptoms. This entry mainly deals with the superior SCDS.
Diplacusis, also known as diplacusis binauralis, binauralis disharmonica or interaural pitch difference (IPD), is a hearing disorder whereby a single auditory stimulus is perceived as different pitches between ears. It is typically experienced as a secondary symptom of sensorineural hearing loss, although not all patients with sensorineural hearing loss experience diplacusis or tinnitus. The onset is usually spontaneous and can occur following an acoustic trauma, for example an explosive noise, or in the presence of an ear infection. Sufferers may experience the effect permanently, or it may resolve on its own. Diplacusis can be particularly disruptive to individuals working within fields requiring acute audition, such as musicians, sound engineers or performing artists.
Hearing, or auditory perception, is the ability to perceive sounds through an organ, such as an ear, by detecting vibrations as periodic changes in the pressure of a surrounding medium. The academic field concerned with hearing is auditory science.
Tinnitus maskers are a range of devices based on simple white noise machines used to add natural or artificial sound into a tinnitus sufferer's environment in order to mask or cover up the ringing. The noise is supplied by a sound generator, which may reside in or above the ear or be placed on a table or elsewhere in the environment. The noise is usually white noise or music, but in some cases, it may be patterned sound or specially tailored sound based on the characteristics of the person's tinnitus.
Auditory fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the auditory threshold known as a temporary threshold shift (TTS). The damage can become permanent if sufficient recovery time is not allowed before continued sound exposure. When the hearing loss is rooted from a traumatic occurrence, it may be classified as noise-induced hearing loss, or NIHL.
Causes of hearing loss include ageing, genetics, perinatal problems, loud sounds, and diseases. For some kinds of hearing loss the cause may be classified as of unknown cause.
Computational audiology is a branch of audiology that employs techniques from mathematics and computer science to improve clinical treatments and scientific understanding of the auditory system. Computational audiology is closely related to computational medicine, which uses quantitative models to develop improved methods for general disease diagnosis and treatment.
Susan Ellen Shore is an American audiologist who is the Merle Lawrence Collegiate Professor of Otolaryngology at the University of Michigan. She was elected Fellow of the American Association for the Advancement of Science in 2021.
Ototoxicity is defined as the toxic effect on the functioning of the inner ear, which may lead to temporary or permanent hearing loss (cochleotoxic) and balancing problems (vestibulotoxic). Drugs or pharmaceutical agents inducing ototoxicity are regarded as ototoxic medications.
About 75% of new cases are related to emotional stress as the trigger factor rather than to precipitants involving cochlear lesions.
There are presently no FDA-approved drugs specifically for tinnitus, and no medications that have been shown to reverse the neural hyperactivity at the root of tinnitus. Drugs cannot cure tinnitus, but they may provide relief from some severe tinnitus symptoms.