A hearing impairment is a decrease in the ability to perceive sound. This article discusses the biologic basis of hearing impairment in humans and other animals. The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) is a detailed description of known diseases and injuries. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) is a detailed description of known diseases and injuries. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... Sound is a disturbance of mechanical energy that propagates through matter as a wave. ...

Explanation

Hearing impairment can affect any creature that hears. Sound varies in amplitude (loudness) and frequency (pitch). Most animals are able to sense sound energy, but no individual animal species can detect all frequencies of sound at all amplitudes (levels of loudness). In fact, although there is much overlap, each species has a different set of audible sounds. Within that range of audible sound, each species is attuned to an even narrower range of pitches that it hears best — usually the sorts of sounds that are important for survival. In social animals, like humans, who use sound as a primary means of communication (spoken language), hearing is most sensitive for the pitches that are produced in speech. Sound is a disturbance of mechanical energy that propagates through matter as a wave. ... Spoken language is a language that people utter words of the language. ...

The medical term hearing impairment has become controversial due to very strong objections from the deaf community who refute the implication of a disability. Those who consider themselves part of Deaf Culture feel offended by the term "impaired". However, not all people, especially those who become deaf in later years, may make this distinction. (See Models of Deafness) Deaf community and Deaf culture are two phrases used to refer to persons who are culturally Deaf as opposed to those who are deaf from the medical/audiological/pathological perspective. ... Deafness, or the state of being deaf, is most commonly defined as the inability of the unaided ear to perceive sounds. ...

Hearing deficiencies: loudness, pitch, and discrimination

Hearing sensitivity is generally indicated by the quietest sound that an individual can detect, called the hearing threshold. In the case of people (and some animals), this threshold can be accurately measured by behavioral tests. That measurement is called a behavioral audiogram. A record is made of the quietest level of sound that consistently prompts a response from the listener. The test is carried out for sounds of different frequencies. Behavioral audiograms require a certain amount of co-operation and training on the part of the individual being tested that other types of hearing tests do not require. Instead of observing behavior these tests rely on technical measurements of activity in the auditory nervous system. These electro-physiological tests of hearing include Auditory Evoked Potentials and Oto-acoustic emissions. An Audiogram is a graphical representation of how well a certain person can perceive different sound frequencies. ...

Normal hearing thresholds are not the same for all frequencies in any species of animal. If different pitches of sound are played at the same amplitude (loudness), some will be loud and clear, and others muffled or even completely inaudible. Generally, if the gain is increased, a pitch is more likely to be perceived. Ordinarily, when animals use sound to communicate, hearing in that type of animal is most sensitive for the pitches produced by calls, or, in the case of humans, speech. This tuning of hearing exist at many levels of the body, all the way from the physical characteristics of the ear, to the nerves and tracts that convey the nerve impulses of the auditory portion of the brain.

A hearing impairment exists when an individual is not sensitive to the sounds normally heard by its kind. In human beings, the term hearing impairment is usually reserved for people who have relative insensitivity to sound in the speech frequencies. The severity of a hearing impairment is categorized according to how much louder a sound must be made over the usual levels before the listener can detect it. In profound deafness, even the loudest sounds that can be produced by the instrument used to measure hearing (audiometer) may not reach threshold.

There is another aspect to hearing that involves the quality of a sound rather than amplitude. In people, that aspect is usually measured by tests of "speech discrimination". Basically, these tests require that the sound is not only detected but understood. There are very rare types of hearing impairments which affect discrimination alone.

References: eBook: Current Diagnosis & Treatment in Otolaryngology: Head & Neck Surgery, Lalwani, Anil K. (Ed.) Chapter 44: Audiologic Testing by Robert W. Sweetow, PhD, Jennifer McKee Bold, AuD, Access Medicine

Types of hearing impairment

Hearing impairment comes from different biologic causes. Most commonly, the ear is the affected part of the body.

Conductive

Conductive hearing loss occurs when sound is not normally conducted through the outer or middle ear (or both). Since sound can be picked up by a normally sensitive inner ear even if the ear canal, ear drum, and ear ossicles are not working, conductive hearing loss is often only mild and is never worse than a moderate impairment. Hearing thresholds will not rise above 55-60 dB from outer or middle ear problems alone. Generally, with pure conductive hearing loss, the quality of hearing (speech discrimination) is good, as long as the sound is amplified loud enough to be easily heard.

Sensory

Hearing loss due to insensitivity of the inner ear, the cochlea, can also be only mild or moderate but can also be much more severe, causing insensitivity to even the loudest sounds (total deafness). Most cases of human deafness (severe to profound hearing impairment) are due to insensitivity of the cochlea at the level of the hair-cell, which is the sound receptor cell that actually transduces sound vibration into the nerve impulses that stimulate the auditory portion of the VIIIth Cranial Nerve. Hearing loss caused either by problems in the cochlea ,or by the auditory portion of the central nervous system, is categorized medically as sensory or sensorineural hearing loss. The great majority of human sensory hearing loss is caused by abnormalities in the cochlea. There are also very unusual sensorineural hearing impairments that involve the VIIIth cranial nerve or the auditory portions of the brain. In the rarest of these sorts of hearing loss, only the auditory centers of the brain are affected. In this situation, central hearing loss, sounds may be heard at normal thresholds, but the quality of the sound perceived is so poor that speech can not be understood.

Age of onset of hearing impairment

If the hearing loss occurs at a young age, interference with the acquisition of spoken language and social skills may occur. Hearing aids, which amplify the incoming sound, may alleviate some of the problems caused by hearing impairment, but are often insufficient. Cochlear implants artificially stimulate the VIIIth Nerve by providing an electric impulse substitution for the firing of hair cells. Cochlear implants are not only expensive, but require sophisticated programming in conjunction with patient training for effectiveness. People who have hearing impairments, especially those who develop a hearing problem in childhood or old age, require support and technical adaptations as part of the rehabilitation process. Spoken language is a language that people utter words of the language. ... Social skills are skills a social animal uses to interact and communicate with others to assist status in the social structure and other motivations. ... Behind the ear aid A hearing aid is a device used to help hard-of-hearing people hear sounds better. ... Cochlear implants are hearing devices that can help people with certain kinds of hearing impairment or who are entirely deaf. ...

Causes

There are many causes of hearing loss.

Conductive hearing loss

• Ear canal obstruction
• Middle-ear Abnormalities
  • Tympanic Membrane
  • Ossicles

Sensory hearing loss

Most sensory hearing loss is due to poor hair cell function. The hair cells may be abnormal at birth, or damaged during the lifetime of an individual. There are both external causes of damage, like noise trauma and infection, and instrinsic abnormalities, like deafness genes.

Sensory hearing loss (also called sensorineural hearing loss) may also result from abnormalities of the VIII cranial nerve.

Sensory hearing loss that results from abnormalities of the central auditory system in the brain is called Central Hearing Impairment. Since the auditory pathways cross back and forth on both sides of the brain, deafness from a central cause is unusual.

Long term exposure to environmental noise

Populations of people living near airports or freeways are exposed to levels of noise typically in the 65 to 75 dbA range. If lifestyles include significant outdoor or open window conditons, these exposures over time can degrade hearing. The U.S. EPA and various states have set noise standards to protect people from these adverse health risks. The EPA has identified the level of 70 db(A) for 24 hour exposure as the level necessary to protect the public from hearing loss (EPA, 1974). EPA redirects here. ... EPA redirects here. ...

• Noise-Induced Hearing Loss (NIHL) typically is centered at 4000 Hz.
• The louder the noise is, the shorter the safe amount of exposure is. Normally, the safe amount of exposure is reduced by a factor 2 for every additional 3 dB(A). For example, the safe daily exposure amount at 85 dB is 8 hours, while the safe exposure at 91 dB(A) is only 2 hours (National Institute for Occupational Safety and Health, 1998). Sometimes, a factor 2 per 5 dB(A) is used.
• Personal electronic audio devices, such as iPods (iPods often reaching 115 decibels or higher), can produce powerful enough sound to cause significant Noise-Induced Hearing Loss, given that lesser intensities of even 70 dB can also cause hearing loss.

A grayscale fourth-generation iPod with earphones. ...

Genetic

Hearing loss can be inherited. Both dominant and recessive genes exist which can cause mild to profound impairment. If a family has a dominant gene for deafness it will persist across generations because it will manifest itself in the offspring even if it is inherited from only one parent. If a family had genetic hearing impairment caused by a recessive gene it will not always be apparent as it will have to be passed onto offspring from both parents Dominant and recessive hearing impairment can be syndromic or nonsyndromic. Recent gene mapping has identified dozens of nonsyndromic dominant (DFNA#) and recessive (DFNB#) forms of deafness. In genetics, the term dominant gene refers to the allele that causes a phenotype that is seen in a heterozygous genotype. ... This article or section does not cite its references or sources. ...

• The most common type of congenital hearing impairment in developed countries is DFNB1, also known as Connexin 26 deafness or GJB2-related deafness.
• The most common dominant syndromic forms of hearing impairment include Stickler syndrome and Waardenburg syndrome.
• The most common recessive syndromic forms of hearing impairment are Pendred syndrome, Large vestibular aqueduct syndrome and Usher syndrome.

Stickler syndrome (or David-Stickler syndrome or Stickler-Wagner syndrome) is a group of inherited connective tissue disorders affecting collagen. ... Waardenburg syndrome is an inherited disorder associated with hearing loss and changes in skin and hair pigmentation. ... Pendred syndrome or Pendred disease is a genetic disorder leading to sensorineural hearing loss and goitre with occasional hypothyroidism. ... Usher syndrome is a genetic disease causing deaf-blindness. ...

Disease or illness

• Measles may result in auditory nerve damage
• Meningitis may damage the auditory nerve or the cochlea
• Autoimmune disease has only recently been recognized as a potential cause for cochlear damage. Although probably rare, it is possible for autoimmune processes to target the cochlea specifically, without symptoms affecting other organs. Wegener's granulomatosis is one of the autoimmune conditions that may precipitate hearing loss.
• Mumps (Epidemic parotitis) may result in profound sensorineural hearing loss (90 dB or more), unilateral (one ear) or bilateral (both ears).
• Presbyacusis is deafness due to loss of perception to high tones, mainly in the elderly. It is considered by some to be a degenerative process, although there has never been a proven link to aging. (See impact of environmental noise exposure above.)
• Adenoids that do not disappear by adolescence may continue to grow and may obstruct the Eustachian tube, causing conductive hearing impairment and nasal infections that can spread to the middle ear.
• AIDS and ARC patients frequently experience auditory system anomalies.[1]
• HIV (and subsequent opportunistic infections) may directly affect the cochlea and central auditory system.[2]
• Chlamydia may cause hearing loss in newborns to whom the disease has been passed at birth.[3]
• Fetal alcohol syndrome is reported to cause hearing loss in up to 64% of infants born to alcoholic mothers, from the ototoxic effect on the developing fetus plus malnutrition during pregnancy from the excess alcohol intake.[4]
• Premature birth results in sensorineural hearing loss approximately 5% of the time.[5]
• Syphilis is commonly transmitted from pregnant women to their fetuses, and about a third of the infected children will eventually become deaf.[6]
• Otosclerosis is a hardening of the stapes (or stirrup) in the middle ear and causes conductive hearing loss.

The vestibulocochlear nerve is the eighth of twelve cranial nerves and also known as the auditory nerve. ... Meningitis is inflammation of the membranes (meninges) covering the brain and the spinal cord. ... Cross section of the cochlea. ... Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. ... Cross section of the cochlea. ... In medicine (rheumatology), Wegeners granulomatosis is a form of vasculitis that affects the lungs, kidneys and other organs. ... Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve (Cranial nerve VIII), the inner ear, or central processing centers of the brain. ... The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ... Presbycusis, or age-related hearing loss, is the cumulative effect of aging on hearing. ... Old age consists of ages nearing the average lifespan of human beings, and thus the end of the human life cycle. ... Adenoids, or pharyngeal tonsils, are folds of lymphatic tissue covered by ciliated epithelium. ... American high school students Adolescence (Latin adolescentia, from adolescere, to grow up) is the period of psychological and social transition between childhood and adulthood (gender-specific, manhood or womanhood). ... Anatomy of the human ear. ... The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. ... Acquired Immune Deficiency Syndrome (AIDS or Aids) is a collection of symptoms and infections in humans resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV). ... AIDS-related complex, or ARC, was introduced by the discovery of the acquired immune deficiency syndrome in homosexual men in 1981. ... Human immunodeficiency virus or HIV is a retrovirus that causes Acquired Immunodeficiency Syndrome (AIDS), a condition in which the immune system begins to fail, leading to life-threatening opportunistic infections. ... Chlamydia is a common term for infection with any bacteria belonging to the phylum Chlamydiae. ... A thin upper lip and a smooth philtrum are signs of FAS Fetal alcohol spectrum disorder is an umbrella term used to describe fetal alcohol syndrome (FAS) and the less noticeable, but sometimes equally serious, fetal alcohol effects (FAE). ... Alcoholism is the consumption of, or preoccupation with, alcoholic beverages to the extent that this behavior interferes with the drinkers normal personal, family, social, or work life, and may lead to physical or mental harm. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless, mildly toxic chemical compound with a distinctive perfume-like odor, and is the alcohol found in alcoholic beverages. ... Premature birth (also known as preterm birth, or premie) is defined medically as childbirth occurring earlier than 37 completed weeks of gestation. ... Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve (Cranial nerve VIII), the inner ear, or central processing centers of the brain. ... Syphilis is a sexually transmitted infection (STI) caused by a spirochaete bacterium, Treponema pallidum. ... Otosclerosis is a hearing condition in which the stapes in the ear becomes attached to the surrounding bone by an abnormal bone growth. ...

Medications

See also Ototoxicity

Some medications cause irreversible damage to the ear, and are limited in their use for this reason. The most important group is the aminoglycosides (main member gentamicin). Ototoxicity is damage of the ear (oto), specifically the cochlea or auditory nerve and sometimes the vestibulum, by a toxin (often medication). ... Aminoglycosides are a group of antibiotics that are effective against certain types of bacteria. ... Gentamicin is a aminoglycoside antibiotic, and can treat many different types of bacterial infections, particularly Gram-negative infection. ...

Various other medications may reversibly affect hearing. This includes some diuretics, aspirin and NSAIDs, and macrolide antibiotics. A diuretic (colloquially called a water pill) is any drug or herb that elevates the rate of bodily urine excretion (diuresis). ... Aspirin or acetylsalicylic acid (acetosal) is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ... Non-steroidal anti-inflammatory drugs, usually abbreviated to NSAIDs, are drugs with analgesic, antipyretic and anti-inflammatory effects - they reduce pain, fever and inflammation. ... The macrolides are a group of drugs (typically antibiotics) whose activity stems from the presence of a macrolide ring, a large lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, are attached. ...

Extremely heavy Vicodin abuse is known to cause hearing impairment. There has been speculation that radio talk show host Rush Limbaugh's hearing loss was at least in part caused by his admitted addiction to narcotic pain killers, in particular Vicodin and OxyContin. It has been suggested that Vicodin be merged into this article or section. ... Rush Hudson Limbaugh III (born January 12, 1951) is an American radio talk show host. ... OxyContin should not be confused with oxytocin. ...

Physical trauma

• There can be damage either to the ear itself or to the brain centers that process the aural information conveyed by the ears.
• People who sustain head injury are especially vulnerable to hearing loss or tinnitus, either temporary or permanent.
• Exposure to very loud noise (90 dB or more, such as jet engines at close range) can cause progressive hearing loss. Exposure to a single event of extremely loud noise (such as explosions) can also cause temporary or permanent hearing loss.

Tinnitus (ti-NIGHT-us or TIN-i-tus[1]) is the perception of sound in the absence of a corresponding external sound. ... NOiSE is a one volume manga created by Tsutomu Nihei as a prequel to his acclaimed ten-volume work, Blame!. It offers some rather sketchy information concerning the Megastructures origins and initial size, as well as the origins of Silicon life. ... The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ...

Categories of hearing impairment

Hearing loss is categorized by its severity and by the age of onset. Two persons with the same severity of hearing loss will experience it quite differently if it occurs early or late in life. Furthermore, a loss can occur on only one side (unilateral) or on both (bilateral).

Types

There are three major types of hearing loss: neural/sensorineural, conductive, or a combination of both. Treatment depends upon the type of hearing loss that is present.

Sensorineural

Sensorineural hearing loss is caused by damage/malfunction of the inner ear (cochlea, eighth cranial nerve) or auditory brainstem. This can be divided further into a sensory hearing loss (inner ear) or a neural hearing loss (brainstem). Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve (Cranial nerve VIII), the inner ear, or central processing centers of the brain. ...

Conductive

Conductive hearing loss is caused by damage/malfunction of the middle or outer ear system (external ear canal, ear drum, or structures in the middle ear space including the malleus, incus and stapes bones). Conductive hearing loss is a failure in the efficient conduction of sound waves through the outer ear, typanic membrane (eardrum) or middle ears (ossicles). ...

Combination

Mixed hearing loss is caused by both conductive and sensorineural causes.

Quantification of hearing loss

The severity of hearing loss is measured by the degree of loudness, as measured in decibels, a sound must attain before being detected by an individual. Hearing loss may be ranked as mild, moderate, severe or profound. It is quite common for someone to have more than one degree of hearing loss (i.e. mild sloping to severe). The following list shows the rankings and their corresponding decibel ranges: The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. ...

• Mild:
  • for adults: between 25 and 40 dB
  • for children: between 15 and 40 dB
• Moderate: between 41 and 55 dB
• Moderately severe: between 56 and 70 dB
• Severe: between 71 and 90 dB
• Profound: 90 dB or greater

The quietest sound you can hear at different frequencies is plotted on an audiogram to reflect your ability to hear at different frequencies. The range of normal human hearing (from the softest audible sound to the loudest comfortable sound) is so great, that the audiogram must be plotted using a logarithmic scale. This, and the different amount of hearing loss at different frequencies, make it virtually impossible to accurately describe the amount of hearing loss in simple terms such as percentages or the rankings, above.

Pre- or postlingual

The age at which the hearing impairment develops is crucial to spoken language acquisition. Post-lingual hearing impairments are far more common than pre-lingual impairments.

Pre-lingual deafness

Main article: Prelingual deafness

Prelingual hearing impairment exists when the impairment is congenital or otherwise acquired before the individual has acquired speech and language, thus rendering the disadvantages more difficult to treat because the child is unable to access audible /spoken communication from the outset. It is important to note that those children born into signing families have no delay in language development and communication. Most pre-lingual hearing impairment is due to an acquired condition, usually either disease or trauma; therefore, families commonly have no prior knowledge of deafness. A profoundly prelingually deaf individual is someone who was born with insufficient hearing to acquire speech normally, or who lost their hearing prior to the age at which speech is acquired. ... A profoundly prelingually deaf individual is someone who was born with insufficient hearing to acquire speech normally, or who lost their hearing prior to the age at which speech is acquired. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... Look up Speech in Wiktionary, the free dictionary. ...

Post-lingual hearing impairment

Main article: Post-lingual hearing impairment

Post-lingual hearing impairment where hearing loss is adventitious after the acquisition of speech and language, usually after the age of six. It may develop due to disease, trauma, or as a side-effect of a medicine. Typically, hearing loss is gradual, and often detected by family and friends of the people so affected long before the patients themselves will acknowledge the disability. Common treatments includes hearing aids and learning lip reading. Loneliness and depression can arise as a result of isolation (from the inability to communicate with friends and loved ones) and difficulty in accepting their disability. Post-lingual hearing impairment is a hearing impairment where hearing loss is adventitious and develops due to disease or trauma after the acquisition of speech and language, usually after the age of six. ... Contagious redirects here. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ...

Hard-of-hearing

People who are hard of hearing have varying amounts of hearing loss but usually not enough to be considered deaf. Many people who are deaf consider spoken language their primary language and consider themselves "hard of hearing". How one classifies themselves relative to hearing loss or deafness is a very personal decision and reflects much more than just their ability to hear.

The phrase hard of hearing, normally used as an adjective or adverb, can also be used as a noun, referring to people with hearing impairment as the hard of hearing. People who consider themselves culturally deaf, prefer the term "hard of hearing" or "deaf", and perceive "hearing impaired" as an insult. Deaf community and Deaf culture are two phrases used to refer to persons who are culturally Deaf as opposed to those who are deaf from the medical/audiological/pathological perspective. ...

Hearing impaired persons with partial loss of hearing may find that the quality of their hearing varies from day to day, or from one situation to another or not at all. They may also, to a greater or lesser extent, depend on both hearing-aids and lip-reading. They may perhaps not always be aware of it, but they do admit to it being important to see the speaker's face in conversation.

Many people with hearing loss have better hearing in the lower frequency ranges (low tones), and cannot hear as well or at all in the higher frequencies. Some people may merely find it difficult to differentiate between words that begin with consonantal sounds such as the fricatives or sibilants, z, or th, or the plosives d, t, b, or p. They may be unable to hear thin, high-pitched or metallic noises, such as birds chirping or singing, clocks ticking, etc. Often, they are able to hear and understand men's voices better than women's. Fricatives (or spirants) are consonants produced by forcing air through a narrow channel made by placing two articulators close together. ... A sibilant is a type of fricative, made by speeding up air through a narrow channel and directing it over the sharp edge of the teeth. ... A stop or plosive or occlusive is a consonant sound produced by stopping the airflow in the vocal tract. ...

Others will find their condition so much worse if circumstances in their immediate environment affect the way they are able to use their hearing aids, or prevent them from employing their speech reading skills. A room with a high ceiling and a lot of reverberation will affect the sound of a speaker's voice adversely. The position of the listener, too, sitting at a right angle to the speaker at a long seminar table, thus being able to hear only with one, maybe the ineffectual ear, can make a difference. Difficulties can also arise for the listener trying to lip-read, if the speaker is sitting with his back against the light-source and is in this way obscuring his face. A rule of thumb is that bright lighting is to the hearing-impaired what noise is to the hearing; a source of distraction. When sound is produced in a space, multiple reflections may build up and blend together, creating reverberation, or reverb. ...

The speaker's accent; the topic under discussion, possibly with many unfamiliar words; the softness of his voice; possibly his having a speech impediment; a habit of holding a hand in front of his mouth or turning his face away at times: all these tendencies cause problems to the hard-of-hearing, especially when they have to rely on lip-reading. The rustling of papers, and notebook pages being turned are precisely the noises that will be the first thing hearing-aids pick up. Speech disorders are a type of communication disorders where normal speech is disrupted. ...

Noisy situations are especially difficult, because hearing loss not only affects the ability to hear sounds, but also to localize and filter out background noise.

Unilateral hearing loss

People with unilateral hearing loss (single sided deafness/SSD) can hear normally in one ear, but have trouble hearing out of the other ear. Problems with this type of deficit is inability to localize sounds (ie. unable to tell where traffic is coming from) and inability to process out background noise in a noisy environment, such as in a restaurant. People with unilateral hearing loss can hear normally in one ear, but have trouble hearing out of the other ear. ...

Social impact

Pre-lingual impairment

In children, hearing loss can lead to social isolation for several reasons. First, the child experiences delayed social development that is in large part tied to delayed language acquisition. It is also directly tied to their inability to pick up auditory social cues. This can result in a deaf person becoming generally irritable. A child who uses sign language, or identifies with the deaf sub-culture does not generally experience this isolation, particularly if he/she attends a school for the deaf, but may conversely experience isolation from his parents if they do not know sign language. A child who is exclusively or predominantly oral (using speech for communication) can experience social isolation from his or her hearing peers, particularly if no one takes the time to explicitly teach her social skills that other children acquire independently by virtue of having normal hearing. Finally, a child who has a severe impairment and uses some sign language may be rejected by his or her deaf peers, because of an understandable hesitation in abandoning the use of existent verbal and speech-reading skills. Some in the deaf community can view this as a rejection of their own culture and its mores, and therefore will reject the individual preemptively. For other meanings of development used in and outside social sciences, see development. ... Language acquisition is the process by which the language capability develops in a human. ... Deaf community and Deaf culture are two phrases used to refer to persons who are culturally Deaf as opposed to those who are deaf from the medical/audiological/pathological perspective. ... A sign language (also signed language) is a language which uses manual communication instead of sound to convey meaning - simultaneously combining handshapes, orientation and movement of the hands, arms or body, and facial expressions to express fluidly a speakers thoughts. ... The term mores (IPA ) as used in sociology is a plural noun. ...

Post-lingual impairment

Those who lose their hearing later in life, such as in late adolescence or adulthood, face their own challenges. For example, they must adjust to living with the adaptations that make it possible for them to live independently. They may have to adapt to using hearing aids or a cochlear implant, develop speech-reading skills, and/or learn sign language. The affected person may need to use a TTY (teletype), interpreter, or relay service to communicate over the telephone. Loneliness and depression can arise as a result of isolation (from the inability to communicate with friends and loved ones) and difficulty in accepting their disability. The challenge is made greater by the need for those around them to adapt to the person's hearing loss. Teletype machines in World War II A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ...

Many relationships have suffered because of the anger that occurs when there is general miscommunication between family members. Generally, it's not only the person with a hearing disability that feels isolated, but others around them who feel they are not being "heard" or paid attention to, especially when the hearing loss has been gradual. Many people opt not to choose hearing aids for fear of looking old, since hearing loss is usually associated with old age and that in turn equals ineffectiveness in our society. Family members then feel as if their hearing loss partner doesn't care about them enough to make changes to reduce their disability and make it easier to communicate.

Medical treatments

Approaches

In addition to hearing aids there exist cochlear implants of increasing complexity and effectiveness. These are useful in treating the mild to profound hearing impairment when the onset follows the acquisitions of language and in some cases in children whose hearing loss came before language was acquired. Recent research shows variations in effacacy but some promising studies[7] show that if implanted at a very young age, some profoundly impaired children can acquire effective hearing and speech. A hearing aid is a device used to help the hard-of-hearing hear sounds better. ... Illustration of the internal parts of a cochlear implant A cochlear implant is a surgically implanted electronic device that can help provide a sense of sound to a person who is profoundly deaf or severely hard of hearing. ...

Views of treatments

There is controversy in the culturally deaf community as to whether cochlear implants address wellness concerns, the overall health and psycho-emotional well-being of prelingually deaf children at all.

Gene therapy

In 2005, there was success of the regrowth of cochlea cells in test subjects by a research team led by Dr. Yehoash Raphael from the University of Michigan. This study was conducted using Guinea Pigs as test subjects. [8] It is important to note however, that the regrowth of cochlear hair cells does not imply the restoration of hearing sensitivity as the sensory cells may or may not make connections with neurons that carry the signals from hair cells to the brain.

A team led by Dr. Stefan Heller from Stanford University are pioneering stem cell research in the prospect of regrowth in cochlea cells.[9]

Adaptations to hearing impairment

Many hearing impaired individuals use certain assistive devices in their daily lives. Individuals can communicate by telephone using telecommunications devices for the deaf (TDD) This device looks like a typewriter or word processor and transmits typed text over the telephone. Other names in common use are textphone and minicom. In 2004, mobile textphone devices came onto the market for the first time allowing simultaneous two way text communication. In the U.S., the UK, the Netherlands and many other western countries there are telephone relay services so that a hearing impaired person can communicate with a hearing person via a human translator. Wireless, internet and mobile phone/SMS text messaging are beginning to take over the role of the TDD. Other assistive devices include those that use flashing lights to signal events such as a ringing telephone, a doorbell, or a fire alarm. Video conferencing is also a new technology that permits signed conversations as well as permitting an ASL-English interpreter to voice and sign conversations between a hearing impaired and hearing person, negating the need to use a TTY or computer keyboard. A telecommunications device for the deaf (TDD) is an electronic device for text communication via a telephone line, used when one or more of the parties has hearing or speech difficulties. ... Mechanical desktop typewriters, such as this Underwood Five, were long time standards of government agencies, newsrooms, and sales offices. ... A word processor (also more formally known as a document preparation system) is a computer application used for the production (including composition, editing, formatting, and possibly printing) of any sort of viewable or printed material. ... Wireless is an old-fashioned term for a radio transceiver (a mixed receiver and transmitter device), referring to its use in wireless telegraphy early on, or for a radio receiver. ... SMS arrival notification on a Siemens phone Short Message Service (SMS) is a service available on most digital mobile phones (and other mobile devices, e. ... A received SMS being announced on a Nokia phone. ... Categories: Wikipedia cleanup | Groupware | Telecommunications stubs ... American Sign Language (ASL, Ameslan) is the dominant sign language of the Deaf community in the United States, in the English-speaking parts of Canada, and in parts of Mexico. ... A teleprinter (teletypewriter, teletype or TTY) is a now largely obsolete electro-mechanical typewriter which can be used to communicate typed messages from point to point through a simple electrical communications channel, often just a pair of wires. ... A computer keyboard is a peripheral modeled after the typewriter keyboard. ...

Resources

• Many different assistive technologies, such as hearing aids, are available to people who are hearing impaired.
• Hearing dogs, a category of assistance dogs, are trained to help those with hearing impairments.
• The advent of the internet's World Wide Web and closed captioning has given the hearing impaired unprecedented access to information. Electronic mail and online chat have virtually eliminated the need for hearing impaired people to use a third-party Telecommunications Relay Service in order to communicate with the hearing and other hearing impaired people.

Assistive Technology (AT) is a generic term that includes assistive, adaptive, and rehabilitative devices and the process used in selecting, locating, and using them. ... Hearing dogs, called signal dogs in the past and also sound alert dogs, hearing ear dogs, or hearing assist dogs, are a category of assistance dogs that are especially selected and trained to assist people who are deaf or hard of hearing. ... An assistance dog is a dog trained to help a person with a disability. ... WWWs historical logo designed by Robert Cailliau The World Wide Web (WWW or simply the Web) is a global, read-write information space. ... A commonly-used symbol indicating that a program or movie is closed-captioned. ... Electronic mail, abbreviated e-mail or email, is a method of composing, sending, and receiving messages over electronic communication systems. ... Chat may refer to a casual conversation an internet chat room or instant messaging system Internet relay chat, a particular chat room system Chat, a kind of bird Chat, the waste rocks produced in mining Le Chat, a Belgian comic strip Khat, a narcotic plant Chats, the way British soldiers... Telecommunications Relay Service (TRS, Relay Service, IP-Relay) is an operator service that allows Deaf, Hard-of-Hearing and Speech-Disabled persons to place calls to standard telephone users via TDD (TTY), personal computer or other assistive telephone device. ...

Bibliography

U.S. Environmental Protection Agency press release, April 2, 1974 EPA redirects here. ...

See also

• Models of deafness for a comparison of the medical, disability and cultural models of deafness.
• Deaf culture
• Deaf history
• Audism, discrimination against Deaf and hard-of-hearing people
• Noise pollution
• Post-lingual hearing impairment
• Pre-lingual deafness
• Progressive hearing loss
• Unilateral hearing loss
• Hearing loss with craniofacial syndromes
• Auditory Brainstem Response (ABR) Test

Deafness, or the state of being deaf, is most commonly defined as the inability of the unaided ear to perceive sounds. ... Deaf community and Deaf culture are two phrases used to refer to persons who are culturally Deaf as opposed to those who are deaf from the medical/audiological/pathological perspective. ... Deaf History The end of the Rennaissance marked an increase in peoples awareness of the Deaf. ... Audism is a term used to describe discrimination or stereotypes against deaf or hard of hearing people--for example, by assuming that the cultural ways of hearing people are somehow better or the only way things can be. ... Noise pollution is unwanted human-created sound that disrupts the environment. ... Post-lingual hearing impairment is a hearing impairment where hearing loss is adventitious and develops due to disease or trauma after the acquisition of speech and language, usually after the age of six. ... A profoundly pre-lingually deaf individual is someone who was born with insufficient hearing to acquire speech normally, or who lost their hearing prior to the age at which speech is acquired. ... People with unilateral hearing loss can hear normally in one ear, but have trouble hearing out of the other ear. ... Hearing loss with craniofacial syndromes is a common occurrence. ... Auditory Brainstem Response or Auditory Brainstem Response Audiometry is a screening test to monitor for hearing loss or deafness in newborn infants. ...

Quotations

• "Blindness cuts you off from things; deafness cuts you off from people." — Helen Keller
• "What matters deafness of the ear, when the mind hears. The one true deafness, the incurable deafness, is that of the mind." — Victor Hugo
• "Deaf people can do anything except hear.". -- I. King Jordan

Blindness is the condition of lacking visual perception due to physiological or psychological factors. ... Helen Adams Keller (June 27, 1880 – June 1, 1968) was a deafblind American author, activist and lecturer. ... Victor-Marie Hugo (26 February 1802 – 22 May 1885) was a French poet, novelist, playwright, essayist, visual artist, statesman and human rights campaigner, recognized as the most influential Romantic writer of the 19th century. ... I. King Jordan (b. ...

External links

• CDC's "Learn the Signs. Act Early.” campaign - Information for parents on early childhood development and developmental disabilities such as hearing loss

The Better Hearing Institute [10],a not-for-profit for 35 years, offers comprehensive information on hearing loss, celebrities who have overcome hearing loss, hearing aids, and hearing loss prevention. We also provide scholarly research on the U.S. hearing loss population as well as publish unbiased information on customer satisfaction with hearing aids.

• Hear-it: Advice to help your hearing — large website on hearing and hearing loss
• Deaf Websites
• Hearing Loss Education Center.
• 'Sir John 'Kappa' Cornforth' Nobel Laureate Freeview video of a scientist who overcame his deafness to pursue a brilliant career in science. Provided by the Vega Science Trust.
• Discussion groups, and shared information on hearing loss.
• National Association of the Deaf. The NAD protects deaf and hard of hearing civil rights.
• Newborn hearing screening information from Children's Hospital, Seattle.
• Help for Hard of Hearing Advocacy, Support and Discussion Board
• American Academy of Audiology Information about hearing loss and a directory of audiologists in the US.
• Deaf 24/7Internet resource for all British Sign Language and deafness related information especially in United Kingdom.
• Hearing Loss Web: A resource specifically for the hearing impaired, as opposed to the deaf.
• Deaf Chat Forum: A forum for deaf and hard of hearing, as well as interested parties.
• Deaf Social Network: First social network for the deaf and hard of hearing.
• Hearing Loss News: News and articles pertaining to hearing loss, cochlear implant, tinnitus, etc.
• Association of Late-Deafened Adults: A website for the post-lingually deaf.
• Workplace Hearing Service
• American Speech-Language Hearing Association (ASHA)
• Alexander Graham Bell Association for the Deaf and Hard of Hearing: Advocates the use of spoken language to communicate and further independence.
• Parenting Hard of Hearing Children
• Did Drugs Cause Rush Limbaugh's Deafness? An interview with Dr. Jennifer Derebery, one of the doctors who treated the talk show host after his hearing loss.
• Hearing Informer Information about hearing loss for hearing

impaired adults and children. Personal stories about coping with hearing loss.

• The EAR Foundation: Non-profit organization dedicated to education about hearing loss issues
• 1 in 2 Baby Boomers Have a Hearing Loss: 2004 study by Clarity and The EAR Foundation.
• U.S. Environmental Protection Agency Standards Statement
• Deaf Social Network
• H.E.A.R. - Hearing Education and Awareness for Rockers
• Hearing Loss News
• Noise-induced Hearing Loss What it is, how it develops, what to do about it. A nontechnical discussion, written especially for Hare Krishna devotees but relevant for anyone.
• Deaf Chat Forum
• A DeafWiki free-content encyclopedia of deaf and hard hearing