Hearing loss - Wikipedia. Hearing loss. Synonymshard of hearing; anakusis or anacusis is total deafness. A common condition that results in hearing loss is chronic ear infections. Certain infections during pregnancy such as syphilis and rubella may also cause hearing loss. Hearing loss is diagnosed when hearing testing finds that a person is unable to hear 2. This includes by immunization, proper care around pregnancy, avoiding loud noise, and avoiding certain medications. For many hearing aids, sign language, cochlear implants and subtitles are useful. Lip reading is another useful skill some develop. Access to hearing aids, however, is limited in many areas of the world. The severity of a hearing loss is categorized according to the increase in volume above the usual level necessary before the listener can detect it. Deafness is defined as a degree of loss such that a person is unable to understand speech even in the presence of amplification. In total deafness, no sounds at all, regardless of amplification or method of production, are heard. Speech perception - Another aspect of hearing involves the perceived clarity of a word rather than the amplitude of sound made by the word. In humans, that aspect is usually measured by tests of speech perception. These tests measure one's ability to understand speech, not to merely detect sound. There are very rare types of hearing loss which affect speech perception alone. B does not represent absence of sound, but rather the softest sound an average unimpaired human ear can hear; some people can hear down to - 5 or even - 1. Read the latest biotechnology articles on biotech industry leaders, emerging biotech companies, FDA decisions, VC deals, and other biotech industry news.Using other people’s research or ideas without giving them due credit is plagiarism. Featured Book Encyclopedia of Personality and Individual Differences Published 2017 New books and journals are available every day.
B. 1. 30 d. B represents the threshold of pain. But the ear doesn't hear all frequencies equally well; hearing sensitivity peaks around 3. Hz. There are many qualities of human hearing besides frequency range and amplitude that can't easily be measured quantitatively. But for many practical purposes, normative hearing is defined by a frequency versus amplitude graph, or audiogram, charting sensitivity thresholds of hearing at defined frequencies. Because of the cumulative impact of age and exposure to noise and other acoustic insults, 'typical' hearing may not be normative. For some kinds of hearing loss the cause may be classified as of unknown cause. Description: Madison Who's Who is more than a registry of accomplished individuals. We provide a forum for executives and professionals to introduce themselves to one. There is a progressive loss of ability to hear high frequencies with aging known as presbycusis. For men, this can start as early as 2. Although genetically variable it is a normal concomitant of ageing and is distinct from hearing losses caused by noise exposure, toxins or disease agents. By correcting for age in assessing hearing, one tends to overestimate the hearing loss due to noise for some and underestimate it for others. As noise damage progresses, damage spreads to affect lower and higher frequencies. On an audiogram, the resulting configuration has a distinctive notch, called a 'noise' notch. As aging and other effects contribute to higher frequency loss (6–8 k. Hz on an audiogram), this notch may be obscured and entirely disappear. Various governmental, industry and standards organizations set noise standards. Environmental Protection Agency has identified the level of 7. B(A) (4. 0% louder to twice as loud as normal conversation; typical level of TV, radio, stereo; city street noise) for 2. As 3 d. B represents a doubling of intensity of sound, duration of exposure must be cut in half to maintain the same energy dose. For workplace noise regulation, the . Note that for some people, sound may be damaging at even lower levels than 8. B A. Exposures to other ototoxins (such as pesticides, some medications including chemotherapy agents, solvents, etc.) can lead to greater susceptibility to noise damage, as well as causing its own damage. This is called a synergistic interaction. Since noise damage is cumulative over long periods of time, persons who are exposed to non- workplace noise, like recreational activities or environmental noise, may have compounding damage from all sources. Some national and international organizations and agencies use an exchange rate of 4 d. B or 5 d. B. For example, at 1. B (nightclub music level), a 3 d. B exchange rate would limit exposure to 1. B exchange rate allows an hour. Many people are unaware of the presence of environmental sound at damaging levels, or of the level at which sound becomes harmful. Common sources of damaging noise levels include car stereos, children's toys, motor vehicles, crowds, lawn and maintenance equipment, power tools, gun use, musical instruments, and even hair dryers. Noise damage is cumulative; all sources of damage must be considered to assess risk. If one is exposed to loud sound (including music) at high levels or for extended durations (8. B A or greater), then hearing loss will occur. Sound intensity (sound energy, or propensity to cause damage to the ears) increases dramatically with proximity according to an inverse square law: halving the distance to the sound quadruples the sound intensity. In the USA, 1. 2. Studies of primitive peoples indicate that much of what has been attributed to age- related hearing loss may be long term cumulative damage from all sources, especially noise. People living in preindustrial societies have considerably less hearing loss than similar populations living in modern society. Among primitive people who have migrated into modern society, hearing loss is proportional to the number of years spent in modern society. Around 7. 5–8. 0% of all these cases are inherited by recessive genes, 2. X- linked patterns, and fewer than 1% are inherited by mitochondrial inheritance. Syndromic deafness occurs when there are other signs or medical problems aside from deafness in an individual. This accounts for around 3. From a genetic standpoint, this accounts for the other 7. These are diseases that have deafness as one of the symptoms or as a common feature associated with it. Many of the genetic mutations giving rise to syndromic deafness have been identified. In nonsyndromic cases, where deafness is the only finding, it is more difficult to identify the genetic mutation although some have been discovered. Recent gene mapping has identified several nonsyndromic dominant (DFNA#) and recessive (DFNB#) forms of deafness. The first gene mapped for non- syndromic deafness, DFNA1, involves a splice site mutation in the formin related homolog diaphanous 1 (DIAPH1). A single base change in a large Costa Rican family was identified as causative in a rare form of low frequency onset progressive hearing loss with autosomal dominant inheritance exhibiting variable age of onset and complete penetrance by age 3. It can also be associated with abnormalities of the inner ear giving rise to an additional sensorineural component to the hearing loss (mixed deafness). Mutations in PTPRQ are a cause of autosomal- recessive nonsyndromic hearing loss. The risk of hearing loss is greatest for those weighing less than 1. Disorders. Multiple sclerosis, or MS, is an autoimmune disease where the immune system attacks the myelin sheath, a covering that protects the nerves. If the auditory nerve becomes damaged, the affected person will become completely deaf in one or both ears. There is no cure for MS. This usually occurs as a consequence of trauma, including barotrauma, and can give rise to vertigo as well as hearing loss. The patient may be generally unwell at the time. Although rare, it is possible for autoimmune processes to target the cochlea specifically as a first presentation. Granulomatosis with polyangiitis is one of the autoimmune conditions that may precipitate hearing loss. Cogan's syndrome commonly presents with hearing loss. Otosclerosis is a condition that can cause fixation of the stapes (or stirrup) in the middle ear preventing its movement and causing a conductive hearing loss. Vestibular schwannoma, erroneously known as Acoustic neuromas, and other types of brain tumors can cause hearing loss by infringement of the tumor on the vestibulocochlear nerve. Congenital problems. Medications. These medications are considered ototoxic. This includes loop diuretics such as furosemide and bumetanide, non- steroidal anti- inflammatory drugs (NSAIDs) both over- the- counter (aspirin, ibuprofen, naproxen) as well as prescription (celecoxib, diclofenac, etc.), paracetamol, quinine, and macrolide antibiotics. The link between NSAIDs and hearing loss tends to be greater in women, especially those who take ibuprofen six or more times a week. Food and Drug Administration (FDA) announced that a warning about possible sudden hearing loss would be added to drug labels of PDE5 inhibitors, which are used for erectile dysfunction. It damages the cochlea with lesions and degrades central portions of the auditory system. People who sustain head injury are especially vulnerable to hearing loss or tinnitus, either temporary or permanent. The process is as follows: sound waves are transmitted to the outer ear, sound waves are conducted down to ear canal, bringing the sound waves to the eardrum which they cause to vibrate, these vibrations are now passed through the 3 tiny ear bones in the middle ear, which transfer the vibrations to the fluid in the inner ear, the fluid moves the hair cells, the movement of the hair cells cause the vibrations to be converted into nerve impulses, the nerve impulses are taken to the brain by the auditory nerve. This is why if anything goes wrong at either the mechanical or neural portion of the process, it could result in sound not being processed by the brain, hence, leading to hearing loss. Lesions to the auditory association cortex produced by physical trauma can result in deafness and other problems in auditory perception. The place where the lesion occurs on the auditory cortex plays an important role in what type of hearing deficit will occur in a person. A study conducted by Clarke et al.
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