Tinnitus

Tinnitus is a condition characterized by the auditory perception of a ringing sensation or various other phantom sounds in the absence of an external acoustic stimulus, which are not audible to others. The term tinnitus derives from the Latin word tinnire, meaning "to ring".

Tinnitus is a condition when a person hears a ringing sound or a different variety of sounds when no corresponding external sound is present and that other people cannot hear. The word tinnitus comes from the Latin tinnire, "to ring".

Tinnitus frequently co-occurs with hearing loss and impaired speech intelligibility in challenging acoustic settings. Its prevalence is substantial, impacting approximately 10–15% of the population. While the majority of individuals manage the condition without significant distress, it poses a severe clinical challenge for only 1–2% of affected individuals.

Tinnitus is not classified as a disease itself, but rather as a symptom that can arise from diverse underlying etiologies and may originate at any point within the auditory pathway or from extra-auditory sources. Predominant etiologies include auditory damage, specifically noise-induced hearing loss, and age-related hearing impairment, termed presbycusis. Additional contributing factors encompass ear infections, cardiovascular pathologies, Ménière's disease, brain tumors, acoustic neuromas (tumors affecting the auditory nerves), migraines, temporomandibular joint disorders, exposure to certain ototoxic medications, prior cranial trauma, and cerumen impaction. For certain individuals, tinnitus impairs cognitive focus and is frequently correlated with anxiety and depressive disorders. Its onset or exacerbation may coincide with periods of heightened emotional stress. A higher incidence of tinnitus is observed among individuals diagnosed with depression.

Diagnosis of tinnitus typically relies on the patient's subjective report of symptoms. This clinical assessment is frequently corroborated by an audiogram, alongside comprehensive otolaryngological and neurological examinations. The impact of tinnitus on an individual's quality of life can be quantitatively assessed using standardized questionnaires. Should specific pathological indicators be identified, diagnostic imaging, such as magnetic resonance imaging (MRI), may be warranted. Further diagnostic procedures are appropriate when tinnitus exhibits a pulsatile characteristic, synchronized with the cardiac rhythm. Infrequently, the sound may be auscultated by an examiner using a stethoscope, a phenomenon termed "objective tinnitus". On occasion, spontaneous otoacoustic emissions—sounds physiologically generated by the inner ear—can manifest as tinnitus.

Preventive strategies for tinnitus encompass the avoidance of chronic or prolonged exposure to high-intensity noise and the minimization of exposure to ototoxic pharmacological agents and substances. When an identifiable underlying etiology exists, targeted treatment of that cause may yield symptomatic amelioration. Conversely, conventional tinnitus management typically involves psychoeducation or therapeutic counseling, including cognitive behavioral therapy. Acoustic masking devices or hearing aids may offer symptomatic relief. Currently, no pharmacological intervention directly targets the underlying mechanisms of tinnitus.

Signs and Symptoms

Tinnitus is frequently characterized as a ringing sensation; however, it can also manifest as clicking, buzzing, hissing, or roaring sounds. The perceived intensity can range from soft to loud, and its pitch from low to high. Its perceived origin may be unilateral, bilateral, or diffuse within the head. The temporal pattern can be intermittent or continuous. For certain individuals, the perceived intensity of tinnitus can be modulated by movements of the shoulder, neck, head, tongue, jaw, or eyes.

Course

Variations in study methodologies contribute to a lack of consistent findings regarding the natural course of tinnitus. Typically, the prevalence of tinnitus increases with advancing age in adult populations, and subjective annoyance ratings tend to escalate with prolonged persistence during follow-up periods.

Adverse Psychological Effects

While many individuals adapt to the bothersome nature of tinnitus, persistent forms can induce anxiety and depression in a subset of the population. The level of tinnitus-related annoyance correlates more strongly with an individual's psychological state than with the objective loudness or frequency characteristics of the perceived sound. Among individuals experiencing highly bothersome tinnitus, common psychological sequelae include depression, anxiety, sleep disturbances, and impaired concentration. A particular study identified additional complications such as cognitive decline and communication difficulties, noting that 45% of tinnitus patients within that cohort had experienced an anxiety disorder at some point in their lives. In severe instances, tinnitus can contribute to suicidal ideation; although suicidal behavior is multifactorial, tinnitus may serve as a contributing risk factor. A cross-sectional analysis of 292 patients attending a Tinnitus and Hyperacusis Clinic in the United Kingdom in 2019 revealed that 15.75% reported experiencing suicidal and self-harm ideations within the preceding two weeks.

Psychological research has concentrated on the distress reaction to tinnitus to explain variations in its perceived severity. Studies indicate that within the examined population, initial conditioning experiences associated the perception of tinnitus with adverse emotional states, including fear and anxiety.

Types

Tinnitus is typically categorized as either "subjective" or "objective." Subjective tinnitus is the more common form, signifying that the sounds perceived by the individual are not discernible through current medical or audiological diagnostic methods. Alternative designations for subjective tinnitus include "tinnitus aurium," "non-auditory," or "non-vibratory" tinnitus.

Infrequently, tinnitus may be audible to another person using a stethoscope. More exceptionally, in some instances, it can be objectively measured as a spontaneous otoacoustic emission (SOAE) within the ear canal. This phenomenon is categorized as "objective tinnitus," alternatively termed "pseudo-tinnitus" or "vibratory" tinnitus.

Subjective Tinnitus

Subjective tinnitus represents the predominant form. It can arise from numerous etiologies, but is most frequently associated with hearing impairment. When originating from inner ear or auditory nerve pathologies, it is termed "otic" (derived from the Greek word for ear). Such otological or neurological conditions encompass those induced by infections, pharmaceutical agents, or physical trauma. One specific etiology involves traumatic noise exposure, which damages the sensory cilia, or hair cells, within the inner ear. Furthermore, research indicates that prolonged exposure to noise pollution, such as that from heavy traffic, may elevate the propensity for tinnitus development.

If no apparent association with inner ear or auditory nerve dysfunction exists, tinnitus may be designated as "non-otic." Approximately 30% of tinnitus cases are modulated by the somatosensory system, where individuals can modulate their tinnitus perception through movements of the face, head, jaw, or neck. This variant is referred to as somatic or craniocervical tinnitus, given that only head or neck movements elicit this modulatory effect.

Certain forms of tinnitus may originate from neuroplastic changes within the central auditory pathway. According to this hypothesis, disrupted sensory input, often due to hearing loss, precipitates these alterations, representing a homeostatic neuronal response within the central auditory system, thereby inducing tinnitus.

When specific sound frequencies are compromised due to hearing impairment, the auditory system exhibits compensatory amplification of these frequencies, ultimately generating persistent sound sensations at those frequencies, even in the absence of an external auditory stimulus.

Hearing Loss

Hearing loss represents the most prevalent etiology of tinnitus. While hearing impairment can stem from diverse origins, cochlear injury is identified as the primary cause among individuals experiencing tinnitus.

In numerous instances, the underlying etiology remains unidentifiable.

Ototoxic medications can also induce subjective tinnitus, either by directly causing hearing loss or by exacerbating damage resulting from loud noise exposure. Such damage can manifest even at dosages not typically classified as ototoxic. Over 260 pharmaceutical agents have been documented to list tinnitus as an adverse effect.

Tinnitus can also arise following the cessation of therapeutic benzodiazepine regimens. It occasionally presents as a prolonged symptom of benzodiazepine withdrawal, potentially enduring for several months. Furthermore, drugs like bupropion are known to induce tinnitus.

Associated Factors

Factors associated with tinnitus include:

• Auditory and Otological Conditions:
  • Conductive hearing impairment
    • Acoustic trauma
    • Exposure to high-intensity noise or music
    • Middle ear effusion
    • Otitis
    • Otosclerosis
    • Eustachian tube dysfunction
  • Sensorineural hearing impairment
    • Excessive or high-intensity noise exposure (e.g., acoustic trauma)
    • Presbycusis (age-related hearing impairment)
    • Ménière's disease
    • Endolymphatic hydrops
    • Superior canal dehiscence
    • Acoustic neuroma
    • Heavy metal toxicity (e.g., mercury or lead poisoning)
    • Ototoxic medications
• Neurological Conditions:
  • Chiari malformation
  • Multiple sclerosis
  • Cranial trauma
  • Giant cell arteritis
• Temporomandibular joint dysfunction
• Metabolic Conditions:
  • Vitamin B₁₂ deficiency
  • Iron deficiency anemia
• Psychiatric Conditions:
  • Depression
  • Anxiety disorders
• Miscellaneous Factors:
  • Vasculitis
  • Certain psychedelic compounds may induce transient tinnitus-like symptoms as an adverse effect:
    • 5-MeO-DET
    • Diisopropyltryptamine (DiPT)
  • Benzodiazepine withdrawal
  • Intracranial hyper- or hypotension, potentially induced by conditions such as encephalitis or a cerebrospinal fluid leak, can also contribute to tinnitus.

Objective Tinnitus

Objective tinnitus represents a distinct form of the condition, wherein individuals perceive sounds originating from their own muscle contractions or pulse. These sounds commonly arise from jaw muscle movements or from blood flow within the neck or facial regions. This variant of tinnitus can occasionally be attributed to involuntary muscle twitching, known as myoclonus, or to an underlying vascular disorder. Furthermore, middle ear myoclonus, characterized by muscle spasms surrounding the middle ear, can also generate tinnitus.

Spontaneous otoacoustic emissions (SOAEs), which are subtle, high-frequency tones generated within the inner ear and detectable in the ear canal using a sensitive microphone, are another potential cause of tinnitus. Approximately 8% of individuals experiencing both SOAEs and tinnitus exhibit SOAE-linked tinnitus, while SOAEs are estimated to account for 4% of all tinnitus cases.

Pediatric Tinnitus

Children can experience either pulsatile or continuous tinnitus, often associated with vascular anomalies or variations impacting the middle and inner ear structures. Computed tomography (CT) scans can assess structural integrity, while magnetic resonance (MR) scans are useful for evaluating nerves and identifying potential masses or malformations. Prompt diagnosis is crucial to mitigate long-term developmental impairments.

Pulsatile Tinnitus

Individuals may perceive a sound synchronized with their heartbeat, a condition termed pulsatile tinnitus or vascular tinnitus. This form of tinnitus is typically objective, stemming from altered blood flow or heightened blood turbulence in proximity to the ear, as observed in conditions like atherosclerosis or venous hum. However, it can also manifest as a subjective experience due to an amplified awareness of blood flow within the ear.

The differential diagnosis for pulsatile tinnitus is extensive, encompassing vascular etiologies, neoplastic growths, middle or inner ear disorders, and various other intracranial pathologies. Vascular origins of pulsatile tinnitus include venous conditions (e.g., a high-riding or dehiscent jugular bulb, sigmoid sinus diverticulum), arterial conditions (e.g., cervical atherosclerosis, or potentially life-threatening issues like carotid artery aneurysm or carotid artery dissection), and dural arteriovenous fistulas or arteriovenous malformations.

Furthermore, pulsatile tinnitus can signify vasculitis, particularly giant cell arteritis. Tumors, such as paragangliomas (e.g., glomus tympanicum, glomus jugulare) or hemangiomas (e.g., facial nerve or cavernous), can also induce pulsatile tinnitus. Middle ear pathologies contributing to pulsatile tinnitus include a patulous eustachian tube, otosclerosis, or middle ear myoclonus (e.g., stapedial or tensor tympani myoclonus). The predominant inner ear etiology for pulsatile tinnitus is superior semicircular canal dehiscence. Additionally, pulsatile tinnitus may be indicative of idiopathic intracranial hypertension. As a potential symptom of intracranial vascular abnormalities, pulsatile tinnitus warrants evaluation for irregular noises of blood flow, commonly referred to as bruits.

Pathophysiology

Tinnitus may originate from heightened neural activity within the auditory brainstem, the region responsible for sound processing, leading to hyperexcitation of certain auditory nerve cells. This hypothesis is supported by the frequent co-occurrence of tinnitus and hearing loss.

Tinnitus can induce stress by activating a fight-or-flight response in the brain's neurochemistry, as the brain may interpret the sound as a significant threat. In 2021, research subjects reported an exacerbation of tinnitus during stressful circumstances.

In 2016, three comprehensive reviews underscored the extensive spectrum and potential synergistic pathologies implicated in tinnitus, leading to a diverse array of symptoms and necessitating highly individualized therapeutic approaches.

Diagnosis

The diagnostic methodology for tinnitus involves a thorough medical history and a comprehensive examination of the head, neck, and neurological system. An audiogram is routinely performed, with medical imaging or electronystagmography occasionally utilized. Potentially treatable underlying conditions include middle ear infection, acoustic neuroma, concussion, and otosclerosis.

The comprehensive evaluation of tinnitus typically encompasses an audiometric assessment (hearing test), the quantification of its acoustic characteristics like pitch and loudness, and a psychological evaluation to identify comorbid conditions such as depression, anxiety, and stress, which may correlate with tinnitus severity.

Tinnitus is often defined, in distinction from typical ear noise experiences, as a perception lasting at least five minutes, occurring a minimum of twice weekly. Nevertheless, individuals experiencing tinnitus frequently report more recurrent episodes. Tinnitus can manifest either continuously or intermittently. Even those with constant tinnitus may not perceive it perpetually, becoming aware of it primarily during periods of quiet, such as at night, or in environments with reduced ambient noise. Chronic tinnitus is generally characterized by a duration exceeding six months.

Audiology

Given the high comorbidity of tinnitus and hearing loss, a pure tone audiometric assessment, yielding an audiogram, can aid in identifying underlying etiologies. Furthermore, an audiogram is instrumental in the appropriate fitting of hearing aids for patients with significant hearing impairment. The perceived pitch of tinnitus frequently corresponds to the frequency range of the individual's hearing loss.

Psychoacoustics

The acoustic characterization of tinnitus involves quantifying several parameters, including frequency for monotone tinnitus, or frequency range and bandwidth for narrow-band noise tinnitus. Other measurements include loudness, expressed in decibels (dB) above the hearing threshold at the specified frequency, the mixing-point, and the minimum masking level. Typically, the perceived pitch or frequency range of tinnitus falls between 5 kHz and 10 kHz, with a loudness ranging from 5 to 15 dB above the hearing threshold.

Residual inhibition represents another pertinent parameter of tinnitus, defined as the transient suppression or cessation of tinnitus perception subsequent to a period of auditory masking. The extent of residual inhibition can serve as an indicator of the potential efficacy of tinnitus maskers as a therapeutic intervention.

Hyperacusis

An evaluation for hyperacusis, a condition frequently co-occurring with tinnitus, is also advisable. Research by Anari et al. (1999) indicated that 86% of patients diagnosed with hyperacusis also reported the presence of tinnitus.

Hyperacusis is characterized by adverse reactions to sound and manifests in various forms. A measurable parameter is the Loudness Discomfort Level (LDL), expressed in decibels (dB), which quantifies the subjective threshold of acute discomfort across specified frequencies within the audible range. This establishes a dynamic range between the hearing threshold at a given frequency and the LDL. A constricted dynamic range within a specific frequency band may be indicative of hyperacusis. The typical hearing comfort threshold is generally established between 0 and 20 dB. Normal LDLs typically range from 85 to 90+ dB, with some experts extending this to 100 dB. Consequently, a dynamic range of 55 dB or less suggests the presence of hyperacusis.

Severity

Tinnitus is commonly classified on a severity spectrum, ranging from 'slight' to 'severe,' based on its impact on daily functioning, including disruption of sleep, quiet pursuits, and routine activities. Severe tinnitus has been correlated with less common clinical presentations.

The evaluation of psychological factors associated with tinnitus necessitates the quantification of tinnitus severity and distress, typically assessed through validated self-report questionnaires. These instruments gauge the extent of psychological burden and functional impairment attributable to tinnitus, encompassing its effects on auditory perception, lifestyle, overall health, and emotional state. A comprehensive assessment of general well-being, including levels of anxiety, depression, stress, life stressors, and sleep disturbances, is also crucial in tinnitus evaluation, given the elevated risk of adverse outcomes in these domains, which can both influence and intensify tinnitus symptoms.

Contemporary assessment tools are designed to ascertain the degree of distress and interference, coping mechanisms, and subjective perceptions of tinnitus, thereby guiding therapeutic interventions and monitoring progress. Nevertheless, the existing literature highlights significant variability, inconsistencies, and a lack of methodological consensus in assessment, which impedes the comparative analysis of treatment efficacy. Questionnaires developed for diagnostic purposes or for classifying tinnitus severity can also function as treatment-sensitive outcome measures.

Pulsatile tinnitus

Should a physical examination detect a bruit, indicative of turbulent blood flow, advanced imaging modalities such as transcranial Doppler (TCD) or magnetic resonance angiography (MRA) are warranted.

Differential diagnosis

It is crucial to exclude other potential origins for sounds typically linked to tinnitus. For example, electromagnetic fields prevalent in contemporary wiring and diverse sound signal transmissions represent two identified external sources of high-pitched auditory stimuli. Radio frequency (RF) hearing, a frequently misdiagnosed condition, often simulates tinnitus by causing individuals to perceive objectively audible high-pitched transmission frequencies that resemble tinnitus sensations.

Prevention

Sustained exposure to elevated sound or noise levels can precipitate tinnitus. Preventive measures, such as custom-fitted earplugs or alternative protective devices, can mitigate this risk. Employers often implement hearing loss prevention programs to educate staff and avert hazardous noise exposure. Governmental bodies establish regulations designed to ensure that employees, when adhering to prescribed protocols, face minimal risk of permanent auditory impairment.

Specific demographic groups are recommended to utilize ear protection to avert the risk of tinnitus, particularly that induced by excessive exposure to intense noises, such as wind noise experienced by motorcycle riders. This recommendation extends to military personnel, musicians, DJs, agricultural laborers, and construction workers, as individuals in these professions exhibit a heightened susceptibility compared to the broader populace.

Numerous pharmaceutical agents possess ototoxic properties, which can exert a cumulative impact, thereby exacerbating auditory damage caused by loud noise. Should the administration of ototoxic medications be imperative, meticulous oversight by the prescribing physician regarding prescription specifics, including dosage and interval, may diminish the extent of potential harm.

Management

When a specific underlying etiology is identified, its treatment may result in symptomatic improvement. Conversely, the principal therapeutic approaches for tinnitus involve psychotherapy, sound therapy, or the use of hearing aids. Currently, no pharmacological agents have demonstrated efficacy in treating tinnitus.

Psychological

Cognitive behavioral therapy (CBT) represents the most robustly supported intervention for managing the significant stress potentially associated with tinnitus. CBT effectively reduces the perceived stress among individuals experiencing tinnitus, a benefit that appears distinct from any impact on depression or anxiety. Acceptance and commitment therapy (ACT) also demonstrates potential in tinnitus management. Furthermore, relaxation techniques may offer supplementary benefits. The United States Department of Veterans Affairs has developed a structured clinical protocol known as Progressive Tinnitus Management.

Sound-based interventions

The utilization of sound therapy, whether through hearing aids or tinnitus maskers, may facilitate the brain's ability to disregard the specific tinnitus frequency. Despite limited evidentiary support for these methods, they are not associated with adverse effects. Tinnitus sound therapy encompasses several distinct approaches. One method involves sound modification designed to compensate for an individual's hearing impairment. A second approach is tailored music therapy, specifically notched at the tinnitus frequency, which may influence lateral inhibition within the targeted neural region, thereby potentially suppressing tinnitus perception.

Preliminary evidence suggests the efficacy of tinnitus retraining therapy, an intervention designed to diminish neuronal activity associated with tinnitus. An alternative therapeutic modality for tinnitus involves mobile applications that integrate diverse methods, such as masking, sound therapy, and relaxation exercises. These applications can function either as standalone devices or as control systems for hearing aids.

Neuromonics represents an additional sound-based intervention. Its protocol adheres to the principles of systematic desensitization and comprises a structured, 12-month rehabilitation program. Neuromonics therapy utilizes customized sound signals, transmitted via a patient-worn device, with the objective of targeting the specific frequency range linked to the individual's tinnitus perception.

Physical therapy

Physical therapy interventions for tinnitus primarily aim to alleviate tension in jaw and neck musculature that might exacerbate symptoms. Muscular hypertonicity, especially in masticatory muscles like the masseter and medial pterygoid, can refer pain to the auditory region, resulting in somatic tinnitus. Specialized physical therapists employ neuromuscular techniques to mitigate tension in these anatomical areas, potentially decreasing tinnitus intensity and associated pain in contiguous regions, including the jaw, teeth, and ears.

Medications

As of 2018, no medications were definitively effective for idiopathic tinnitus. Evidence remains insufficient to establish the utility of antidepressants or acamprosate in its management, and studies on benzodiazepine efficacy present conflicting results. The effectiveness of melatonin (as of 2015), anticonvulsants, middle ear steroid injections, and betahistine for treating tinnitus also remains unproven or unclear.

Botulinum toxin injections have demonstrated success in certain rare instances of objective tinnitus attributed to palatal tremor.

In 2009, the use of caroverine for tinnitus treatment was reported in a limited number of countries; however, subsequent review indicated very weak evidence supporting its efficacy.

Neuromodulation

In 2020, clinical trial data suggested that bimodal neuromodulation could alleviate tinnitus symptoms. This noninvasive technique involves the simultaneous application of electrical stimulation to the tongue and auditory stimuli. Associated treatment equipment is accessible via physicians, and ongoing research with this and similar devices is being conducted across multiple research centers.

The Lenire bimodal neuromodulation device, commercialized by Neuromod, received approval as a tinnitus treatment option from the United States Food and Drug Administration (FDA) in March 2023. Subsequently, in June 2024, the United States Department of Veterans Affairs (VA) declared its intention to provide this treatment to veterans afflicted with tinnitus, marking it as the inaugural bimodal neuromodulation device to secure a Federal Supply Schedule (FSS) contract from the U.S. Government.

Certain neuromodulation techniques, including transcranial magnetic stimulation, transcranial direct current stimulation, and neurofeedback, are supported by some evidence.

Nerve damage repair via neurotrophins

Ongoing research explores treatments utilizing neurotrophins to promote auditory nerve repair. In 2023, Stéphane Maison, an auditory physiologist at Massachusetts Eye and Ear Infirmary, stated, "Our work reconciles the idea that tinnitus may be triggered by a loss of auditory nerve, including in people with normal hearing... We won't be able to cure tinnitus until we fully understand the mechanisms underlying its genesis. This work is a first step toward our ultimate goal of silencing tinnitus." This research builds upon prior studies demonstrating neurotrophin-induced nerve repair in other mammalian species, suggesting a potential avenue for investigating human tinnitus treatments.

Alternative medicines not effective

A 2013 report indicated that Ginkgo biloba does not appear to be an effective treatment for tinnitus. The American Academy of Otolaryngology advises against the use of melatonin or zinc supplements for tinnitus symptom relief, reporting in 2014 a lack of evidence for the efficacy of numerous dietary supplements (including lipoflavonoids, garlic, traditional Chinese/Korean herbal medicine, honeybee larvae, various other vitamins and minerals, and homeopathic preparations) in treating tinnitus. Furthermore, a 2016 Cochrane Review concluded that insufficient evidence existed to support the use of zinc supplements for reducing tinnitus-related symptoms.

Prognosis

Although a definitive cure is currently unavailable, the majority of individuals affected by tinnitus adapt to living with the condition over time; however, for a minority, it persists as a substantial challenge.

Epidemiology

Adults

Tinnitus impacts 10–15% of the general population. Approximately one-third of North Americans over 55 years of age experience this condition. While one-third of adults encounter tinnitus at some point in their lives, 10–15% are sufficiently bothered to seek medical assessment. In Europe, an estimated 70 million individuals are affected by tinnitus.

Children

Tinnitus, frequently perceived as an adult condition, is often underestimated in pediatric populations. Despite children's potential inability to articulate the condition or its impact, those with hearing impairment exhibit a significant prevalence of pediatric tinnitus. Children typically do not spontaneously report tinnitus, and their complaints may not receive adequate clinical consideration. For children who do report tinnitus, there is an elevated probability of co-occurring otological or neurological pathologies, including migraines, juvenile Meniere's disease, or chronic suppurative otitis media.

The documented prevalence of tinnitus ranges from 12% to 36% in children possessing normal hearing thresholds, escalating to 66% among those with hearing loss. Furthermore, approximately 3% to 10% of children are reported to experience significant distress due to tinnitus.

Investigational Pharmacotherapies for Tinnitus

• List of investigational tinnitus drugs
• Auditory Hallucination: The perception of sound in the absence of an external auditory stimulus.
• Health Impacts of Noise Exposure: The physiological and psychological consequences resulting from exposure to elevated sound levels.
• Hearing protection
• Noise-induced hearing loss
• Individuals Documented with Tinnitus
• Unexplained Acoustic Phenomena: A compilation of unidentified or previously unidentified sounds.
• Phantom Vibration Syndrome: The erroneous perception of a mobile phone vibrating or ringing when no such event is occurring.
• Safe Listening Practices: Strategies for preventing auditory damage from volitionally heard sounds.
• Zwicker Tone: A transient auditory illusion.

References

Baguley D, Andersson G, McFerran D, McKenna L (2013) [2004]. Tinnitus: A Multidisciplinary Approach (2nd ed.). Indianapolis, IN: Wiley-Blackwell. ISBN 978-1-4051-9989-6. LCCN 2012032714. OCLC 712915603.

• Baguley D, Andersson G, McFerran D, McKenna L (2013) [2004]. Tinnitus: A Multidisciplinary Approach (2nd ed.). Indianapolis, IN: Wiley-Blackwell. ISBN 978-1-4051-9989-6. LCCN 2012032714. OCLC 712915603.Langguth B, Hajak G, Kleinjung T, Cacace A, Møller AR, eds. (2007). Tinnitus: pathophysiology and treatment. Progress in brain research no. 166 (1st ed.). Amsterdam; Boston: Elsevier. ISBN 978-0-444-53167-4. LCCN 2012471552. OCLC 648331153.Møller AR, Langguth B, Ridder D, et al., eds. (2011). Textbook of Tinnitus. New York: Springer. doi:10.1007/978-1-60761-145-5. ISBN 978-1-60761-144-8. LCCN 2010934377. OCLC 695388693, 771366370, 724696022.
  • American Tinnitus Association
  • Tinnitus.org UK