A cochlear implant (CI) is a surgically implanted
neuroprosthesis that provides a person who has moderate-to-profound
sensorineural hearing loss with sound perception. With the help of therapy, cochlear implants may allow for improved speech understanding in both quiet and noisy environments.
A CI bypasses acoustic hearing by direct electrical stimulation of the auditory nerve.
Through everyday listening and auditory training, cochlear implants allow both children and adults to learn to interpret those signals as speech and sound.
The implant has two main components. The outside component is generally worn behind the ear, but could also be attached to clothing, for example, in young children. This component, the sound processor, contains microphones, electronics that include
digital signal processor (DSP) chips, battery, and a coil that transmits a signal to the implant across the skin. The inside component, the actual implant, has a coil to receive signals, electronics, and an array of
electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials d ...
s which is placed into the
cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory or ...
, which stimulate the
cochlear nerve
The cochlear nerve (also auditory nerve or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve. The cochlear nerve carries auditory sensory informatio ...
.
The surgical procedure is performed under
general anesthesia
General anaesthesia (UK) or general anesthesia (US) is a medically induced loss of consciousness that renders the patient unarousable even with painful stimuli. This effect is achieved by administering either intravenous or inhalational general ...
. Surgical risks are minimal and most individuals will undergo
outpatient surgery
Outpatient surgery, also known as ambulatory surgery, day surgery, day case surgery, or same-day surgery, is surgery that does not require an overnight hospital stay.The International Association for Ambulatory Surgery (IAAS) would not consider a ...
and go home the same day. However, some individuals will experience
dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a common medical c ...
, and on rare occasions,
tinnitus
Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...
or facial nerve bruising.
From the early days of implants in the 1970s and the 1980s, speech perception via an implant has steadily increased. More than 200,000 people in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
had received a CI through 2019. Many users of modern implants gain reasonable to good hearing and speech perception skills post-implantation, especially when combined with lipreading. One of the challenges that remain with these implants is that hearing and speech understanding skills after implantation show a wide range of variation across individual implant users. Factors such as age of implantation, parental involvement and education level, duration and cause of hearing loss, how the implant is situated in the cochlea, the overall health of the cochlear nerve, but also individual capabilities of re-learning are considered to contribute to this variation.
History
![Cochlear implant user](https://upload.wikimedia.org/wikipedia/commons/8/86/Cochlear_implant_user.jpg)
André Djourno and Charles Eyriès invented the original cochlear implant in 1957. This original design distributed stimulation using a single channel.
William House also invented a cochlear implant in 1961.
In 1964, Blair Simmons and
Robert J. White implanted a single-channel electrode in a patient's cochlea at Stanford University.
However, research indicated that these single-channel cochlear implants were of limited usefulness because they cannot stimulate different areas of the cochlea at different times to allow differentiation between low and mid to high frequencies as required for detecting speech.
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
engineer Adam Kissiah started working in the mid-1970s on what would become the modern cochlear implant. Kissiah used his knowledge learned while working as an electronics instrumentation engineer at NASA. This work took place over three years, when Kissiah would spend his lunch breaks and evenings in Kennedy's technical library, studying the impact of engineering principles on the inner ear. In 1977, NASA helped Kissiah obtain a patent for the cochlear implant; Kissiah later sold the patent rights.
The modern multi-channel cochlear implant was independently developed and commercialized by two separate teams—one led by
Graeme Clark in Australia and another by
Ingeborg Hochmair and her future husband,
Erwin Hochmair in Austria, with the Hochmairs' device first implanted in a person in December 1977 and Clark's in August 1978.
Parts
Cochlear implants bypass most of the
peripheral auditory system which receives sound and converts that sound into movements of
hair cells
Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates, and in the lateral line organ of fishes. Through mechanotransduction, hair cells detect movement in their environment. ...
in the
cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory or ...
; the deflection of
stereocilia
Stereocilia (or stereovilli or villi) are non-motile apical cell modifications. They are distinct from cilia and microvilli, but are closely related to microvilli. They form single "finger-like" projections that may be branched, with normal cell ...
causes an influx of
potassium ions into the hair cells, and the depolarisation in turn stimulates calcium influx, which increases release of the
neurotransmitter,
glutamate. Excitation of the
cochlear nerve
The cochlear nerve (also auditory nerve or acoustic nerve) is one of two parts of the vestibulocochlear nerve, a cranial nerve present in amniotes, the other part being the vestibular nerve. The cochlear nerve carries auditory sensory informatio ...
send signals to the brain, which creates the
experience
Experience refers to conscious events in general, more specifically to perceptions, or to the practical knowledge and familiarity that is produced by these conscious processes. Understood as a conscious event in the widest sense, experience involv ...
of sound. Instead, the devices pick up sound and digitize it, convert that digitized sound into electrical signals, and transmit those signals to electrodes embedded in the cochlea. The electrodes electrically stimulate the cochlear nerve, causing it to send signals to the brain.
There are several systems available, but generally they have the following components:[
External:
* one or more microphones that pick up sound from the environment
* a speech processor which selectively ]filters
Filter, filtering or filters may refer to:
Science and technology
Computing
* Filter (higher-order function), in functional programming
* Filter (software), a computer program to process a data stream
* Filter (video), a software component tha ...
sound to prioritize audible speech
* a transmitter that sends power and the processed sound signals across the skin to the internal device by radio frequency transmission
Internal:
* a receiver/stimulator, which receives signals from the speech processor and converts them into electric impulses
* an electrode array embedded in the cochlea
A totally implantable cochlear implant (TICI) A totally implantable cochlear implant (TICI) is a new type of cochlear implant and is currently in development. Unlike a conventional cochlear implant, which has both an internal component (the implant) and an external component (the audio processo ...
is currently in development. This new type of cochlear implant incorporates all the current external components of an audio processor into the internal implant. The lack of external components makes the implant invisible from the outside and also means it is less likely to be damaged or break.
Assistive listening devices
Most modern cochlear implants can be used with a range of assistive listening device
An assistive listening device (ALD) is part of a system used to improve hearing ability for people in a variety of situations where they are unable to distinguish speech in noisy environments. Often, in a noisy or crowded room it is almost impossi ...
s (ALDs), which help people to hear better in challenging listening situations. These situations could include talking on the phone, watching TV or listening to a speaker or teacher. With an ALD, the sound from devices including mobile phones or from an external microphone is sent to the audio processor directly, rather than being picked up by the audio processor's microphone. This direct transmission improves the sound quality for the user, making it easier to talk on the phone or stream music.
ALDs come in many forms, such as neckloops, pens, and specialist battery pack covers. Modern ALDs are usually able to receive sound from any Bluetooth device, including phones and computers, before transmitting it wirelessly to the audio processor. Most cochlear implants are also compatible with older ALD technology, such as a telecoil.
Surgical procedure
Surgical techniques
Implantation of children and adults can be done safely with few surgical complications and most individuals will undergo outpatient surgery and go home the same day.
Occasionally, the very young, the very old, or patients with a significant number of medical comorbidities may remain for overnight observation in the hospital. The procedure can be performed in an ambulatory surgery center in healthy individuals.
The surgical procedure most often used to implant the device is called mastoidectomy
A mastoidectomy is a procedure performed to remove the mastoid air cells, air bubbles in the skull, near the inner ears. This can be done as part of treatment for mastoiditis, chronic suppurative otitis media or cholesteatoma. In addition, it is ...
with facial recess approach (MFRA).
The procedure is usually done under general anesthesia. Complications of the procedure are rare, but include mastoiditis
Mastoiditis is the result of an infection that extends to the air cells of the skull behind the ear. Specifically, it is an inflammation of the mucosal lining of the mastoid antrum and mastoid air cell system inside the mastoid process. The ma ...
, otitis media
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, ...
(acute or with effusion), shifting of the implanted device requiring a second procedure, damage to the facial nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste ...
, damage to the chorda tympani
The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the fa ...
, and wound infections.
Cochlear implantation surgery is considered a clean procedure with an infection rate of less than 3%. Guidelines suggest that routine prophylactic antibiotics are not required. However, the potential cost of a postoperative infection is high (including the possibility of implant loss); therefore, a single preoperative intravenous injection of antibiotics is recommended.
The rate of complications is about 12% for minor complications and 3% for major complications; major complications include infections, facial paralysis, and device failure.
Although up to 20 new cases of post-CI bacterial meningitis occur annually worldwide, data demonstrates a reducing incidence. To avoid the risk of bacterial meningitis, the CDC recommends that adults and children undergoing CI receive age-appropriate vaccines that generate antibodies to Streptococcus pneumoniae.
The rate of transient facial nerve palsy is estimated to be approximately 1%. Device failure requiring reimplantation is estimated to occur 2.5–6% of the time. Up to one-third of people experience disequilibrium, vertigo, or vestibular weakness lasting more than one week after the procedure; in people under 70 these symptoms generally resolve over weeks to months, but in people over 70 the problems tend to persist.
In the past, cochlear implants were only approved for people who were deaf in both ears; a cochlear implant had been used experimentally in some people who had acquired deafness in one ear after they had learned how to speak, and none who were deaf in one ear from birth; clinical studies had been too small to draw generalizations.
Alternative surgical technique
Other approaches, such as going through the suprameatal triangle, are used. A systematic literature review published in 2016 found that studies comparing the two approaches were generally small, not randomized, and retrospective so were not useful for making generalizations; it is not known which approach is safer or more effective.
Endoscopic cochlear implantation
With the increased utilization of endoscopic ear surgery as popularized by professor Tarabichi, there have been multiple published reports on the use of endsocopic technique in cochlear impant surgery. However, this has been motivated by marketing and there is clear indication of increased morbidity associated with this technique as reported by the pioneer of endoscopic ear surgery.
Complications of cochlear implant surgery
As cochlear implant surgical techniques have advanced over the last four decades, the global complication rate for CI surgery in both children and adults has decreased from >35% in 1991 to less than 10% at present. The risk of postoperative facial nerve injury has also decreased over the last several decades to less than 1%, most of which demonstrated complete return of function within six months. The rate of permanent paralysis is approximately 1 per 1,000 surgeries and likely less than that in experienced CI centers.
The majority of complications following CI surgery are minor requiring only conservative medical management or prolongation of hospital stay. Less than 5% of all complications are major resulting in surgical intervention or readmission to the hospital. Reported rates of revision cochlear implant surgery vary in adults and children from 3.8% to 8% with the most common indications being device failure, infection, and migration of the implant or electrode. Disequilibrium and vertigo after CI surgery can occur but the symptoms tend to be mild and short-lived. CI rarely results in significant or persistent adverse effects on the vestibular system when hearing conservation surgical techniques are practiced. Moreover, gait and postural stability may actually improve post-implantation.
Outcomes
Cochlear implant outcomes can be measured using speech recognition ability and functional improvements measured using patient reported outcome measures. While the degree of improvement after cochlear plantation may vary, the majority of patients who receive cochlear implants demonstrate a significant improvement in speech recognition ability compared to their preoperative condition.
Meta-analyses from 2017 and 2018 of the literature showed that CI users have large improvements in quality of life after cochlear implantation. This improvement occurs in many different facets of life that extends beyond communication including improved ability to engage in social activities; decreased mental effort from listening; and improved environmental sound awareness. Deaf adolescents with cochlear implants attending mainstream educational settings report high levels of scholastic self-esteem, friendship self-esteem, and global self-esteem. They also tend to hold mostly positive attitudes towards their cochlear implants, and as a part of their identity, a majority either do "not really think about" their hearing loss, or are "proud of it." Though advancements in cochlear implant technology have helped patients in their understanding of language, users are still unable to understand suprasegmental portions of language, which includes pitch.
A study by Johns Hopkins University
Johns Hopkins University (Johns Hopkins, Hopkins, or JHU) is a private research university in Baltimore, Maryland. Founded in 1876, Johns Hopkins is the oldest research university in the United States and in the western hemisphere. It consi ...
determined that for a three-year-old child who receives them, cochlear implants can save $30,000 to $50,000 in special-education costs for elementary and secondary schools as the child is more likely to be mainstreamed in school and thus use fewer support services than similarly deaf children.
Efficacy
A 2019 study found that bilateral cochlear implantation was widely regarded as the most beneficial hearing intervention for acceptable candidates, although it is more likely to be performed and reimbursed in children than adults. The study also found that the efficacy of bilateral implantation could be improved by enhancing communication between the two implants and by developing sound coding strategies specifically for bilateral users.
Early research reviews found that the ability to communicate in spoken language was better the earlier the implantation was performed. The reviews also found that, overall, while cochlear implants provide open-set speech understanding for the majority of implanted profoundly hearing-impaired children, it was not possible to accurately predict the specific outcome of the given implanted child. Research since then has reported long-term socio-economic benefits for children as well as audiological outcomes including improved sound localization and speech perception. A consensus statement from the European Bilateral Pediatric Cochlear Implant Forum also confirmed the importance of bilateral cochlear implantation in children. In adults, new research shows that bilateral implantation can improve quality of life and speech intelligibility in quiet and noise.
A 2015 review examined whether CI implantation to treat people with bilateral hearing loss had any effect on tinnitus
Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...
. This review found the quality of evidence to be poor and the results variable: overall total tinnitus suppression rates for patients who had tinnitus prior to surgery varied from 8% to 45% of people who received CI; decrease of tinnitus was seen in 25% to 72%, of people; for 0% to 36% of the people there was no change; increase of tinnitus occurred in between 0% to 25% of patients; and, in between 0 and 10% of cases, people who did not have tinnitus before the procedure, got it. Further research found that the electrical stimulation of the CI is at least partly responsible for the general reduction in symptoms. A 2019 study found that although tinnitus suppression in patients with CIs is multifactorial, simply having the CI switched on without any audiological input (while standing alone in a soundproof booth) reduced the symptoms of tinnitus. This would suggest that it is the electrical stimulation that explains the decrease in tinnitus symptoms for many patients, and not only the increased access to sound.
A 2015 literature review on the use of CI for people with auditory neuropathy spectrum disorder Auditory neuropathy spectrum disorder (ANSD) is a specific form of hearing loss defined by the presence of normal or near-normal otoacoustic emissions (OAEs) but the absence of normal middle ear reflexes and severely abnormal or completely absent ...
found that, as of that date, description and diagnosis of the condition was too heterogeneous to make clear claims about whether CI is a safe and effective way to manage it.
The data for cochlear implant outcomes in older adults differs. A 2016 research study found that age at implantation was highly correlated with post-operative speech understanding performance for various test measures. In this study, people who were implanted at age 65 or older performed significantly worse on speech perception testing in quiet and in noisy conditions compared to younger CI users. Other studies have shown different outcomes, with some reporting that adults implanted at the age of 65 and older showed audiological and speech discrimination outcomes similar to younger adults. While cochlear implants demonstrate substantial benefit across all age groups, results will depend on cognitive factors that are ultimately highly age dependent. However, studies have documented the benefit of cochlear implants in octogenarians.
The effects of aging on central auditory processing abilities are thought to play an important role in impacting an individual's speech perception with a cochlear implant. The Lancet reported that untreated hearing loss in adults is the number one modifiable risk factor for dementia. In 2017, a study also reported that adults using a cochlear implant had significantly improved cognitive outcomes including working memory, reaction time, and cognitive flexibility compared to people who were waiting to receive a cochlear implant.
Prolonged duration of deafness is another factor that is thought to have a negative impact on overall speech understanding outcomes for CI users. However, a study found no statistical difference in the speech understanding abilities of CI patients over 65 who had been hearing impaired for 30 years or more prior to implantation. In general, outcomes for CI patients are dependent upon the individual's level of motivation, expectations, exposure to speech stimuli and consistent participation in aural rehabilitation programs.
A 2016 systematic review of CI for people with unilateral hearing loss
Unilateral hearing loss (UHL) is a type of hearing impairment where there is normal hearing in one ear and impaired hearing in the other ear.
Signs and symptoms
Patients with unilateral hearing loss have difficulty:
* Hearing conversation on thei ...
(UHL) found that of the studies conducted and published, none were randomized, only one evaluated a control group, and no study was blinded. After eliminating multiple uses of the same subjects, the authors found that 137 people with UHL had received a CI. While acknowledging the weakness of the data, the authors found that CI in people with UHL improves sound localization
Sound localization is a listener's ability to identify the location or origin of a detected sound in direction and distance.
The sound localization mechanisms of the mammalian auditory system have been extensively studied. The auditory system us ...
compared with other treatments in people who lost hearing after they learned to speak; in the one study that examined this, CI did improve sound localization in people with UHL who lost hearing before learning to speak. It appeared to improve speech perception and to reduce tinnitus
Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...
.
In terms of quality of life, several studies have shown that cochlear implants are beneficial in many aspects of quality of life, including communication improvements and positive effects on social, emotional, psychological and physical well-being. A 2017 narrative review also concluded that the quality of life scores of children using cochlear implants were comparable to those of children without hearing loss. Studies involving adults of all ages reported significant improvement in QoL after implantation when compared to adults with hearing aids
A hearing aid is a device designed to improve hearing by making sound audible to a person with hearing loss. Hearing aids are classified as medical devices in most countries, and regulated by the respective regulations. Small audio amplifiers su ...
. This was often independent of audiological performance.
Society and culture
Usage
approximately 188,000 individuals had been fitted with cochlear implants. the same publication cited approximately 324,000 cochlear implant devices having been surgically implanted. In the U.S., roughly 58,000 devices were implanted in adults and 38,000 in children. the Ear Foundation in the United Kingdom, estimates the number of cochlear implant recipients in the world to be about 600,000. The American Cochlear Implant Alliance estimates that 217,000 people received CIs in the United States through the end of 2019.
Cost and Insurance
Cochlear implantation includes the medical device as well as related services and procedures including pre-operative testing, the surgery, and aftercare that includes audiology and speech language pathology services. These are provided over time by a team of clinicians with specialized training. All of these services, as well as the cochlear implant device and related peripherals, are part of the medical intervention and are typically covered by health insurance in the United States and many areas of the world. These medical services and procedures include candidacy evaluation, hospital services inclusive of supplies and medications used during surgery, surgeon and other physicians such as anesthesiologists, the cochlear implant device and system kit, and programming and (re)habilitation following the surgery. In many countries around the world, the cost of cochlear implantation and aftercare is covered by health insurance.
In the USA
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, as cochlear implants have become more commonplace and accepted as a valuable and cost effective health intervention, insurance coverage has expanded to include private insurance, Medicare, Tricare
Tricare (styled TRICARE) is a health care program of the United States Department of Defense Military Health System. Tricare provides civilian health benefits for U.S Armed Forces military personnel, military retirees, and their dependents, ...
, the VA System, other federal health plans, and Medicaid
Medicaid in the United States is a federal and state program that helps with healthcare costs for some people with limited income and resources. Medicaid also offers benefits not normally covered by Medicare, including nursing home care and per ...
. In September 2022 the Centers for Medicare & Medicaid Services
The Centers for Medicare & Medicaid Services (CMS), is a federal agency within the United States Department of Health and Human Services (HHS) that administers the Medicare program and works in partnership with state governments to administer M ...
expanded coverage of cochlear implants for appropriate candidates under Medicare. Candidates must demonstrate limited benefit with appropriately fit hearing aids but with criteria now defined by test scores of less than or equal to 60% correct in the best-aided listening condition on recorded tests of open-set sentence recognition. Just as there is with any medical procedure, there are typically co-pays which vary depending upon the insurance plan.
In the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...
, the NHS
The National Health Service (NHS) is the umbrella term for the publicly funded healthcare systems of the United Kingdom (UK). Since 1948, they have been funded out of general taxation. There are three systems which are referred to using the " ...
covers cochlear implants in full, as does Medicare in Australia, and the Department of Health in Ireland
Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...
, Seguridad Social in Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, Sécurité Sociale in France and Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, and the Ministry of Health or ACC (depending on the cause of deafness) in New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
. In Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
and Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
, the cost is covered by most health insurance organizations.
Public Health
6.1% of the world population live with hearing loss, and it is predicted that by 2050, more than 900 million people around the globe will have a disabling hearing loss. According to a WHO report, unaddressed hearing loss costs the world 980 billion dollars annually. Particularly hard hit are the healthcare and educational sectors, as well as societal costs. 53% of these costs are attributable to low- and middle-income countries.
The WHO reports that cochlear implants have been shown to be a cost-effective way to mitigate the challenges of hearing loss. In a low-to-middle-income setting, every dollar invested in unilateral cochlear implants has a return on investment of 1.46 dollars. This rises to a return on investment of 4.09 dollars in an upper-middle-income setting. A study in Colombia assessed the lifetime investments made in 68 children who received cochlear implants at an early age. Taking into account the cost of the device and any other medical costs, follow-up, speech therapy, batteries and travel, each child required an average investment of US$99 000 over the course of their life (assuming a life span of 78 years for women and 72 years for men). The study concluded that for every dollar invested in rehabilitation of a child with a cochlear implant, there was a return on investment of US$2.07.
Manufacturers
As of 2021, four cochlear implant devices approved for use in the United States are manufactured by Cochlear Limited, Advanced Bionics, MED-EL, and Oticon Medical.
In Europe, Africa, Asia, South America, and Canada, an additional device manufactured by Neurelec
Demant A/S is an international hearing health care company within hearing aids, audiometric equipment, and personal communication.
History
The Demant Group was founded in 1904 by Hans Demant, under the name Oticon. After his death in 1910, ...
(later acquired by Oticon Medical) was available. A device made by Nurotron (China) was also available in some parts of the world. Each manufacturer has adapted some of the successful innovations of the other companies to its own devices. There is no consensus that any one of these implants is superior to the others. Users of all devices report a wide range of performance after implantation.
Criticism and controversy
Much of the strongest objection to cochlear implants has come from within the Deaf community
Deafness has varying definitions in cultural and medical contexts. In medical contexts, the meaning of deafness is hearing loss that precludes a person from understanding spoken language, an audiological condition. In this context it is written ...
, some of whom are pre-lingually deaf people whose first language is a sign language
Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning, instead of spoken words. Sign languages are expressed through manual articulation in combination with non-manual markers. Sign l ...
. Some in the Deaf community call cochlear implants audist and an affront to their culture, which, as they view it, is a minority threatened by the hearing majority. This is an old problem for the Deaf community, going back as far as the 18th century with the argument of manualism vs. oralism. This is consistent with medicalisation and the standardisation of the "normal" body in the 19th century when differences between normal and abnormal began to be debated. It is important to consider the sociocultural context, particularly in regards to the Deaf community, which has its own unique language and culture. This accounts for the cochlear implant being seen as an affront to their culture, as many do not believe that deafness is something that needs to be cured. However, it has also been argued that this does not necessarily have to be the case: the cochlear implant can act as a tool deaf people can use to access the "hearing world" without losing their Deaf identity.
Cochlear implants for congenitally deaf children are most effective when implanted at a young age. Evidence shows that Deaf children of Deaf parents (or with fluent signers as daily caregivers) learn signed language as effectively as hearing peers. Some Deaf-community advocates recommend that all Deaf children should learn sign language from birth, but more than 90% of deaf children are born to hearing parents. Since it takes years to become fluent in sign language, deaf children who grow up without amplification such as hearing aids or cochlear implants will not have daily access to fluent language models in households without fluent signers.
Critics of cochlear implants from Deaf cultures also assert that the cochlear implant and the subsequent therapy often become the focus of the child's identity at the expense of language acquisition and ease of communication in sign language and Deaf identity. They believe that measuring a child's success only by their mastery of speech will lead to a poor self-image as "disabled" (because the implants do not produce normal hearing) rather than having the healthy self-concept of a proudly Deaf person. However, these assertions are not supported by research. The first children to receive cochlear implants as infants are only in their 20s (as of 2020), and anecdotal evidence points to a high level of satisfaction in this cohort, most of whom don't consider their deafness their primary identity.
Children with cochlear implants are most likely to be educated with listening and spoken language, without sign language
Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning, instead of spoken words. Sign languages are expressed through manual articulation in combination with non-manual markers. Sign l ...
and are often not educated with other Deaf children who use sign language. Cochlear implants have been one of the technological and social factors implicated in the decline of sign languages in the developed world. Some Deaf activists have labeled the widespread implantation of children as a cultural genocide
Cultural genocide or cultural cleansing is a concept which was proposed by lawyer Raphael Lemkin in 1944 as a component of genocide. Though the precise definition of ''cultural genocide'' remains contested, the Armenian Genocide Museum defines i ...
.
As the trend for cochlear implants in children grows, Deaf-community advocates have tried to counter the "either or" formulation of oralism
Oralism is the education of deaf students through oral language by using lip reading, speech, and mimicking the mouth shapes and breathing patterns of speech.Through Deaf Eyes. Diane Garey, Lawrence R. Hott. DVD, PBS (Direct), 2007. Oralism ca ...
vs. manualism with a "both and" or "bilingual-bicultural" approach; some schools are now successfully integrating cochlear implants with sign language in their educational programs. However, there is disagreement among researchers about the effectiveness of methods using both sign and speech as compared to sign or speech alone.
Notable recipients (partial list)
* Michael Chorost
Michael Chorost (born December 26, 1964) is an American book author, essayist, and public speaker. Born with severe loss of hearing due to rubella, his hearing was partially restored with a cochlear implant in 2001 and he had his other ear impla ...
- American writer
* Dorinda Cox - Australian politician
* Lou Ferrigno
Louis Jude Ferrigno Sr. (; born November 9, 1951) is an American actor and retired professional bodybuilder. As a bodybuilder, Ferrigno won an IFBB Mr. America title and two consecutive IFBB Mr. Universe titles; and appeared in the documenta ...
- bodybuilder and moviestar
* Rush Limbaugh
Rush Hudson Limbaugh III ( ; January 12, 1951 – February 17, 2021) was an American conservative political commentator who was the host of '' The Rush Limbaugh Show'', which first aired in 1984 and was nationally syndicated on AM and FM r ...
- American conservative radio host
* Heather Whitestone - 1995 Miss America
* Malala Yousafzai
Malala Yousafzai ( ur, , , pronunciation: ; born 12 July 1997), is a Pakistani female education activist and the 2014 Nobel Peace Prize laureate. Awarded when she was 17, she is the world's youngest Nobel Prize laureate, and the second P ...
- Nobel peace prize recipient
See also
* 3D Printing
3D printing or additive manufacturing is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer co ...
3D microscaffold cochlear implant
/ref>
* Auditory brainstem response
The auditory brainstem response (ABR), also called brainstem evoked response audiometry (BERA), is an auditory evoked potential extracted from ongoing electrical activity in the brain and recorded via electrodes placed on the scalp. The measured ...
* Auditory brainstem implant
An auditory brainstem implant (ABI) is a surgically implanted electronic device that provides a sense of sound to a person who is profoundly deaf, due to retrocochlear hearing impairment (due to illness or injury damaging the cochlea or auditory n ...
* Bone-anchored hearing aid
* Bone conduction
Bone conduction is the conduction of sound to the inner ear primarily through the bones of the skull, allowing the hearer to perceive audio content without blocking the ear canal. Bone conduction transmission occurs constantly as sound waves vibra ...
* Brain implant
* Ear trumpet
An ear trumpet is a tubular or funnel-shaped device which collects sound waves and leads them into the ear. They were used as hearing aids, resulting in a strengthening of the sound energy impact to the eardrum and thus improved hearing for a de ...
* Electric Acoustic Stimulation
* Electrophonic hearing
* Neuroprosthetics
Neuroprosthetics (also called neural prosthetics) is a discipline related to neuroscience and biomedical engineering concerned with developing neural prostheses. They are sometimes contrasted with a brain–computer interface, which connects the ...
* Noise health effects
Noise health effects are the physical and psychological health consequences of regular exposure to consistent elevated sound levels. Noise from traffic, in particular, is considered by the World Health Organization to be one of the worst environm ...
* Visual prosthesis
A visual prosthesis, often referred to as a bionic eye, is an experimental visual device intended to restore functional vision in those with partial or total blindness. Many devices have been developed, usually modeled on the cochlear implant or ...
*
References
Further reading
*
External links
*
*
Cochlear Implants
Information from the National Institutes of Health (NIH).
* NAS
Spinoff article
on engineer Adam Kissiah's contribution to cochlear implants beginning in the 1970s.
{{DEFAULTSORT:Cochlear Implant
1979 introductions
1979 in science
Artificial organs
Audiology
Australian inventions
Bionics
Cybernetics
Implants (medicine)
Medical devices
NASA spin-off technologies
Neuroprosthetics
Otology