Hyperacusis | |
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Other names | Hyperacousis |
Specialty | Otolaryngology |
Differential diagnosis | Sensory processing disorder |
Treatment | Tinnitus Retraining Therapy or TRT, Round and Oval Window Reinforcement |
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 (also called noxacusis), annoyance, and fear. [1] [2] It can be a highly debilitating hearing disorder. [3]
There are a variety of causes and risk factors, with the most common being exposure to loud noise. [1] It is often coincident with tinnitus. [1] Proposed mechanisms in the literature involve dysfunction in the brain, inner ear, or middle ear. [4] [5] [6] [7] [8] [9]
Little is known about the prevalence of hyperacusis, in part due to the degree of variation in the term's definition. [1] [10] Reported prevalence estimates vary widely, and further research is needed to obtain strong epidemiological data. [11]
Hyperacusis symptoms can include an increased perception of the loudness of sounds (loudness hyperacusis), pain (noxacusis/pain hyperacusis/sound-induced otalgia), annoyance, and/or fear in response to sounds by which most people are unaffected. It may affect one or both ears. [12] The majority of patients experience bilateral symptoms but often have one ear that is more affected than the other. Annoyance hyperacusis is often considered synonymous with misophonia. Fear hyperacusis is often considered synonymous with phonophobia. Many researchers more narrowly define hyperacusis to only include loudness hyperacusis and pain hyperacusis. [12]
Hyperacusis can also be accompanied by tinnitus. The latter is more common [13] and there are important differences between their involved mechanisms. [3]
Hyperacusis can result in anxiety and stress. Avoidant behavior is often a response to prevent the effects of hyperacusis and this can include avoiding social situations. [14]
Loudness hyperacusis is characterized by an increased perception of the loudness of sounds. [12] It is often associated with certain volumes and/or frequencies. It can occur in children [15] and adults, [16] and can be either "short-term" in a duration of weeks to less than a year before recovery, or, less commonly, "long-term," spanning years and in some cases becoming permanent. Sensitivity is often different between ears. [17]
In some instances, hyperacusis is accompanied by pain, which is known as noxacusis. [18] Noxacusis is characterized by pain resulting from sounds, often initiated at certain volumes or frequencies. [19] Pain can be immediate or delayed, and it sometimes persists for an extended period of time following exposure. [17] Pain can be acute or chronic, and is often described as stabbing, burning, throbbing, or aching. In healthy listeners, pain from sound is not typically experienced until the volume exceeds approximately 120 decibels. [12]
Individuals experiencing noxacusis report less improvement over time and fewer benefits from sound therapy compared to individuals with loudness hyperacusis. [20]
The threshold of sound at which discomfort is initially experienced; measured in decibels (dB). [21]
A setback is a temporary exacerbation of symptoms, a worsening of the perception of loudness or pain from sound, often due to a particular noise exposure. [12] Setback prevention is an important focus among those affected. Efforts to avoid setbacks commonly include using hearing protection and avoiding loud noises. [17] Pain hyperacusis patients experience setbacks more frequently than patients with loudness hyperacusis. [12]
Some conditions that are associated with hyperacusis include: [22] [23]
The most common cause of hyperacusis is overexposure to excessively high decibel (sound pressure) levels, which can cause acoustic trauma. [1] An acoustic shock, which can lead to symptoms such as hyperacusis and ear pain, can also occur after exposure to an unexpected moderately loud to loud noise, even if this does not necessarily result in permanent cochlear damage. [7]
Some affected people acquire hyperacusis suddenly as a result of taking ototoxic drugs (which can damage the cells responsible for hearing), Lyme disease, Ménière's disease, head injury, or surgery. Others are born with sound sensitivity or develop superior canal dehiscence syndrome. [32] Bell's palsy can trigger hyperacusis if the associated flaccid paralysis affects the tensor tympani, and stapedius, two small muscles of the middle ear. [33] Paralysis of the stapedius muscle prevents its function in dampening the oscillations of the ossicles, causing sound to be abnormally loud on the affected side. [34] Age may also be a significant factor, with younger patients exhibiting more severe hyperacusis. [11]
Recently, it has been discovered that individuals with one copy of the GJB2 (Cx26) genetic mutation exhibit hearing that is more sensitive than average, akin to hyperacusis. These individuals appear to be at greater risk for damage from noise. [35]
Some psychoactive drugs such as LSD, methaqualone, benzodiazepines, or phencyclidine can cause hyperacusis. [11] [36] An antibiotic, ciprofloxacin, has also been seen to be a cause, known as ciprofloxacin-related hyperacusis. [37] Benzodiazepine withdrawal syndrome is also a possible cause. [38] [39]
Prevalence estimates for hyperacusis vary widely in the literature, and further epidemiological data is needed. No gender differences have yet been established among hyperacusis patients. Hyperacusis appears to be more severe in younger patients. [11]
As one possible mechanism, adaptation processes in the auditory brain that influence the dynamic range of neural responses are assumed to be distorted by irregular input from the inner ear. This is mainly caused by hearing loss related damage in the inner ear. [4] The mechanism behind hyperacusis is not currently known, but it is suspected to be caused by damage to the inner ear and cochlea.
Type II afferent fibers of the cochlear nerve are not responsible for hearing like the type I afferent fibers. They are thought to be cochlear pain neurons. Gain of function of these type II afferent fibers may be caused by a flood of ATP after hair cell damage. [5] [6] Now sensitized, they react to the small amount of ATP released during the normal process of hearing. This may result in pain. [5] [6]
Noreña et al. (2018) propose a model that may account for sound-induced pain and a constellation of other symptoms often experienced after an acoustic shock, acoustic trauma, and potentially other mechanisms of auditory damage. Symptoms may include a sense of fullness in the ear, tinnitus, and dizziness. [7] [8]
The model details how symptoms may be initiated by tensor tympani muscle damage or overload due to acoustic shock or trauma. Hypercontraction or hyperactivity of the muscle may cause an "ATP energy crisis." The muscle is then forced to create energy without sufficient oxygen, which results in the release of lactic acid into the middle ear space. This acidity can activate pain-sensing neurons. Muscle relaxation requires energy in the form of ATP. In the setting of low ATP, it is more difficult for the muscle to relax, which causes the cycle to continue. Via a cascade of events, the activated pain neurons can cause neurogenic inflammation, which may lead to additional pain. In this way, a "vicious circle" is created. [7] [9]
Pain from sound sometimes radiates to the face, scalp, and neck. This may be due to the trigeminocervical complex in the brainstem, which integrates input from and output to various regions of the head and neck, including the middle ear. Of note, the tensor tympani muscle is innervated by the trigeminal nerve. The model also explains how whiplash injuries, temporomandibular joint dysfunction, and other conditions affecting the head and neck regions may influence the function of the tensor tympani muscle and contribute to ear symptoms such as pain hyperacusis. [7] [8] [9]
The basic diagnostic test is similar to a normal audiogram. The difference is that, in addition to the hearing threshold at each test frequency, the lowest uncomfortable sound level is also measured. This level is called loudness discomfort level (LDL) or uncomfortable loudness level (ULL). In patients with hyperacusis this level is often considerably lower than in normal subjects, and usually across most parts of the auditory spectrum. [1] [40] However, there is not a consensus regarding what constitutes a normal LDL. The relationship between LDL's and self-reported ability to tolerate sounds in everyday life in unclear. [41]
In addition to self-report questionnaires, audiologists may employ a variety of other techniques to evaluate auditory function in patients experiencing noise sensitivity. When conducting testing that involves the presentation of sounds, which may cause the patient discomfort or pain, it is vital to inform the patient of the volume and duration of sounds to be presented prior to testing. Care should be taken to begin with sounds of low volume, and volume should be increased gradually. The audiologist and patient should both be prepared to stop testing at any time, depending on the patient's symptoms. [41]
There are currently no evidence-based guidelines regarding the treatment of patients with hyperacusis. The majority of audiologists report insufficient formal education in this area, likely due in part to the current lack of consensus in the literature regarding definitions and treatment of hyperacusis. [42]
Setback prevention and reduction of pain symptoms are high priorities among those with hyperacusis and noxacusis, which is often managed through a combination of controlling the environment so as to avoid loud sounds, soundproofing, and wearing hearing protection, such as earplugs and safety earmuffs. [43] [44] Preliminary research has shown that individuals with pain hyperacusis can experience an exacerbation of their symptoms when not adequately protecting themselves against loud sounds. [17]
There are diametrically opposing views on avoiding overuse of hearing protection and silence. Some audiologists may advise against using hearing protection in normal sound environments, claiming it can cause or worsen hyperacusis. This is based on a study in healthy volunteers and not individuals with preexisting loudness or pain hyperacusis. [45]
Sound therapy is sometimes recommended for those with hyperacusis, though there is limited evidence supporting its use. [46] Its application among those with pain (noxacusis) should be used with caution. Tinnitus retraining therapy, a treatment originally used to treat tinnitus, uses broadband noise to treat hyperacusis. Pink noise can also be used to treat hyperacusis. By listening to broadband noise at soft levels for a disciplined period of time each day, some patients can rebuild (i.e., re-establish) their tolerances to sound. [2] [47] [48] [49] More research is needed on the efficacy of sound therapy techniques when hyperacusis is the primary complaint, rather than a secondary symptom, indicating that "no strong conclusions can be made" about its efficacy at this time. [15] Importantly, individuals with pain hyperacusis are more likely than individuals with loudness hyperacusis to report worsening of their condition after the use of sound therapy. [20]
Another possible treatment is cognitive behavioral therapy (CBT), which may also be combined with sound therapy. [22] [50] However, randomized controlled trials with active control groups are still needed to establish the effectiveness of CBT for hyperacusis [51] and the usefulness of CBT for noxacusis is not yet demonstrated in the scientific literature.
Studies have shown improved loudness discomfort levels in patients with hyperacusis after round and oval window reinforcement. [15]
A case of chronic ear pain associated with hyperacusis after exposure to loud noise at a concert was successfully treated with tympanic neurectomy. [52]
Patient activists are tracking anecdotal outcomes of certain medications. "Medication and botox spreadsheet" . Retrieved 2024-10-31. The tricyclic anti-depressant clomipramine (brand name Anafranil) has been anecdotally useful for many people with hyperacusis. Both loudness hyperacusis and noxacusis have been successfully treated with this drug. A dosage of up to 200–250 mg daily for a sustained period of six to twelve months may be needed to cure hyperacusis. A possible mechanism of action of this drug is that clomipramine reduces reactions of the autonomic nervous system to sounds. [53]
The drug ambroxol helps relieve the pain experienced by several pain hyperacusis patients.
Suicidal ideations are a risk factor in hyperacusis patients. Hashir et al. (2019) interviewed 292 patients and found that 15.75% had expressed suicidal ideations in the previous two weeks of the study. They recommend screening for these issues. [54]
Ramsay Hunt syndrome type 2, commonly referred to simply as Ramsay Hunt syndrome (RHS) and also known as herpes zoster oticus, is inflammation of the geniculate ganglion of the facial nerve as a late consequence of varicella zoster virus (VZV). In regard to the frequency, less than 1% of varicella zoster infections involve the facial nerve and result in RHS. It is traditionally defined as a triad of ipsilateral facial paralysis, otalgia, and vesicles close to the ear and auditory canal. Due to its proximity to the vestibulocochlear nerve, the virus can spread and cause hearing loss, tinnitus, and vertigo. It is common for diagnoses to be overlooked or delayed, which can raise the likelihood of long-term consequences. It is more complicated than Bell's palsy. Therapy aims to shorten its overall length, while also providing pain relief and averting any consequences.
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.
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. 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. The word tinnitus comes from the Latin tinnire, "to ring". In some people, it interferes with concentration, and can be associated with anxiety and depression.
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.
The acoustic reflex is an involuntary muscle contraction that occurs in the middle ear in response to loud sound stimuli or when the person starts to vocalize.
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.
Auditory neuropathy (AN) is a hearing disorder in which the outer hair cells of the cochlea are present and functional, but sound information is not transmitted sufficiently by the auditory nerve to the brain. The cause may be several dysfunctions of the inner hair cells of the cochlea or spiral ganglion neuron levels. Hearing loss with AN can range from normal hearing sensitivity to profound hearing loss.
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.
The tensor tympani is a muscle within the middle ear, located in the bony canal above the bony part of the auditory tube, and connects to the malleus bone. Its role is to dampen loud sounds, such as those produced from chewing, shouting, or thunder. Because its reaction time is not fast enough, the muscle cannot protect against hearing damage caused by sudden loud sounds, like explosions or gunshots, however some individuals have voluntary control over the muscle, and may tense it pre-emptively.
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.
Cortical deafness is a rare form of sensorineural hearing loss caused by damage to the primary auditory cortex. Cortical deafness is an auditory disorder where the patient is unable to hear sounds but has no apparent damage to the structures of the ear. It has been argued to be as the combination of auditory verbal agnosia and auditory agnosia. Patients with cortical deafness cannot hear any sounds, that is, they are not aware of sounds including non-speech, voices, and speech sounds. Although patients appear and feel completely deaf, they can still exhibit some reflex responses such as turning their head towards a loud sound.
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.
Misophonia is a disorder of decreased tolerance to specific sounds or their associated stimuli, or cues. These cues, known as "triggers", are experienced as unpleasant or distressing and tend to evoke strong negative emotional, physiological, and behavioral responses not seen in most other people. Misophonia and the behaviors that people with misophonia often use to cope with it can adversely affect the ability to achieve life goals, communicate effectively, and enjoy social situations. Originating within the field of audiology in 2001, the condition remained largely undescribed in the clinical and research literature until 2013, when a group of psychiatrists at Amsterdam University Medical Center published a detailed misophonia case series and proposed the condition as a "new psychiatric disorder" with defined diagnostic criteria. At present, misophonia is not listed as a diagnosable condition in the DSM-5-TR, ICD-11, or any similar manual, making it difficult for most people with the condition to receive official clinical diagnoses of misophonia or billable medical services. An international panel of misophonia experts has rigorously established a consensus definition of misophonia as a medical condition, and since its initial publication in 2022, this definition has been widely adopted by clinicians and researchers studying the disorder.
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.
Musicians can experience a number of health problems related to the practice and performance of music. The differences in career paths, occupations and performance scenarios are some of the determinants of a wide range of possible health effects.
Acoustic trauma is the sustainment of an injury to the eardrum as a result of a very loud noise. Its scope usually covers loud noises with a short duration, such as an explosion, gunshot or a burst of loud shouting. Quieter sounds that are concentrated in a narrow frequency may also cause damage to specific frequency receptors. The range of severity can vary from pain to hearing loss.
Tonic tensor tympani syndrome is a disease of the tensor tympani muscle, described by Klochoff et al. in 1971. The tensor tympani muscle is one of the two middle ear muscles that support the three middle ear bones, called the ossicles. TTTS involves tensor tympani muscle activity being reduced, leading to a decrease in the contraction threshold of the tensor tympani which is exaggerated by high stress levels. This hyper-contraction leads to chronic ear pain, in particular in the case of hyperacusis and acoustic shock. TTTS is considered to be a secondary consequence of temporomandibular disorder and temporomandibular joint dysfunction.
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.