Deafness

{{Short description|Loss of hearing}}
{{Redirect|Deaf}}
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'''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 [[Audiology|audiological]] condition.<ref name="Peads2011" /> In this context it is written with a lower case ''d''. It later came to be used in a cultural context to refer to those who primarily communicate through [[sign language]] regardless of [[hearing]] ability, often capitalized as ''Deaf'' and referred to as "big&nbsp;D Deaf" in speech and sign.<ref name="padden2005">{{Cite book|last1=Padden|first1=Carol A.|url=https://books.google.com/books?id=2B4XWIFPgowC&q=Deaf&pg=PA1|title=Inside Deaf Culture|last2=Humphries|first2=Tom (Tom L.)|publisher=Harvard University Press|year=2005|isbn=978-0-674-01506-7|location=Cambridge, MA|page=1}}</ref><ref name="bigD">{{cite web|author=Jamie Berke|date=9 February 2010|title=Deaf Culture - Big D Small D|url=http://deafness.about.com/cs/culturefeatures1/a/bigdorsmalld.htm|access-date=22 November 2013|publisher=About.com|archive-date=4 March 2016|archive-url=https://web.archive.org/web/20160304111043/http://deafness.about.com/cs/culturefeatures1/a/bigdorsmalld.htm|url-status=dead}}</ref> The two definitions overlap but are not identical, as hearing loss includes cases that are not severe enough to impact spoken language comprehension, while cultural Deafness includes hearing people who use sign language, such as [[Child of deaf adult|children of deaf adults]].

== Medical context ==
{{Main|Hearing loss}}[[File:International_Symbol_for_Deafness.svg|thumb|The International Symbol for Deafness is used to identify facilities with hearing augmentation services, especially [[Assistive listening device|assistive listening devices]].<ref>{{Cite web |title=International Deafness Symbol |url=https://www.deafnessforum.org.au/resources/international-deafness-symbol/ |access-date=2022-11-18 |website=Deafness Forum Australia |language=en-AU}}</ref>]]In a medical context, deafness is defined as a degree of hearing difference such that a person is unable to understand speech, even in the presence of amplification.<ref name="Peads2011">{{cite book|last=Elzouki|first=Abdelaziz Y|url=https://books.google.com/books?id=FEf4EMjYSrgC&pg=PA602|title=Textbook of clinical pediatrics|date=2012|publisher=Springer|isbn=9783642022012|edition=2|location=Berlin|pages=602|name-list-style=vanc|archive-url=https://web.archive.org/web/20151214195730/https://books.google.com/books?id=FEf4EMjYSrgC&pg=PA602|archive-date=2015-12-14|url-status=live}}</ref> In profound deafness, even the highest intensity sounds produced by an [[audiometer]] (an instrument used to measure hearing by producing pure tone sounds through a range of frequencies) may not be detected. In total deafness, no sounds at all, regardless of amplification or method of production, can be heard.

Neurologically, language is processed in the same areas of the brain whether one is deaf or hearing. The left hemisphere of the brain processes linguistic patterns whether by signed languages or by spoken languages.<ref name=":0">{{Cite web |last=Campbell |first=Ruth |display-authors=etal |date=29 June 2007 |title=Sign Language and the Brain: A Review |url=https://doi.org/10.1093/deafed/enm035 |access-date=14 Dec 2020 |pages=3–20 |doi=10.1093/deafed/enm035 |pmid=17602162 |journal=Journal of Deaf Studies and Deaf Education |volume=13}}</ref>

Deafness can be broken down into four different types of hearing loss: conductive hearing loss, sensorineural hearing loss, mixed hearing loss, and auditory neuropathy spectrum disorder. All of these forms of hearing loss cause an impairment in a person's hearing where they are not able to hear sounds correctly. These different types of hearing loss occur in different parts of the ear, which make it difficult for the information being heard to get sent to the brain properly. To break it down even further, there are three different levels of hearing loss. According to the CDC, the first level is mild hearing loss. This is when someone is still able to hear noises, but it is more difficult to hear the softer sounds. The second level is moderate hearing loss and this is when someone can hear almost nothing when someone is talking to them at a normal volume. The next level is severe hearing loss. Severe hearing loss is when someone can not hear any sounds when they are being produced at a normal level and they can only hear minimum sounds that are being produced at a loud level. The final level is profound hearing loss, which is when someone is not able to hear any sounds except for very loud ones.<ref>{{cite web |date=21 June 2021 |title=Hearing Loss in Children |url=https://www.cdc.gov/ncbddd/hearingloss/types.html}}</ref>



There are millions of people in the world who are living with deafness or hearing impairments. Survey of Income and Program Participation (SIPP) indicate that fewer than 1 in 20 Americans are currently deaf or hard of hearing.<ref>{{Cite journal |last=Mitchell |first=R. E. |date=2005-10-12 |title=How Many Deaf People Are There in the United States? Estimates From the Survey of Income and Program Participation |url=https://academic.oup.com/jdsde/article-lookup/doi/10.1093/deafed/enj004 |journal=Journal of Deaf Studies and Deaf Education |language=en |volume=11 |issue=1 |pages=112–119 |doi=10.1093/deafed/enj004 |pmid=16177267 |issn=1081-4159|doi-access=free }}</ref>  There are a lot of solutions available for people with hearing impairments. Some examples of solutions would be blinking lights on different things like their phones, alarms, and things that are important to alert them. Cochlear implants are an option too.<ref>{{cite web |title=Know-the-ADA |url=https://know-the-ada.com/t4/history-deafness.html}}</ref> Cochlear implants are surgically placed devices that stimulate the cochlear nerve in order to help the person hear. A cochlear implant is used instead of hearing aids in order to help when someone has difficulties understanding speech.<ref>{{cite web |date=18 July 2022 |title=Cochlear Implant Surgery |url=https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/cochlear-implant-surgery}}</ref>

== Cultural context ==
{{Main|Deaf culture}}
[[File:Sign Union flag.svg|thumb|237x237px|The flag of the deaf community made by [[Arnaud Balard]]]]In a cultural context, [[Deaf culture]] refers to a tight-knit [[cultural group]] of people whose [[primary language]] is [[Sign language|signed]], and who practice social and cultural norms which are distinct from those of the surrounding hearing community. This community does not automatically include all those who are clinically or legally deaf, nor does it exclude every hearing person. According to Baker and Padden, it includes any person who "identifies him/herself as a member of the Deaf community, and other members accept that person as a part of the community",<ref name="book2">{{cite book|last=Baker|first=Charlotte|title=American Sign Language: A Look at Its Story, Structure and Community|year=1978|author2=Carol Padden}}</ref> an example being [[Child of deaf adult|children of deaf adults]] with normal hearing ability. It includes the set of social beliefs, behaviors, art, literary traditions, history, values, and shared institutions of communities that are influenced by deafness and which use [[sign language]]s as the main means of communication.<ref name="padden2005" /><ref name="bigD" /> Members of the Deaf community tend to view deafness as a difference in human experience rather than a [[disability]] or [[disease]].<ref name="ladd2003">{{cite book|last=Ladd|first=Paddy|url=https://books.google.com/books?id=7PRLjkES83oC|title=Understanding Deaf Culture: In Search of Deafhood|publisher=Multilingual Matters|year=2003|isbn=978-1-85359-545-5|page=502|author-link=Paddy Ladd}}</ref><ref name="lane2011">{{cite book|last=Lane|first=Harlan L.|url=https://books.google.com/books?id=KySGdskgT9EC&pg=PA1|title=The People of the Eye: Deaf Ethnicity and Ancestry|author2=Richard Pillard|author3= University Press|year=2011|isbn=978-0-19-975929-3|page=269}}</ref>

Many non-disabled people continue to assume that deaf people have no autonomy and fail to provide people with support beyond hearing aids, which is something that must be addressed. Different non-governmental organizations around the world have created programs towards closing the gap between deaf and non-disabled people in developing countries. As children, deaf people learn literacy differently than hearing children. They learn to speak and write, whereas hearing children naturally learn to speak and eventually learn to write later on. <ref>{{Cite journal |last=Wong |first=Fay |last2=Tang |first2=Gladys |last3=Li |first3=Qun |last4=Yiu |first4=Chris Kun-Man |date=2021 |title=Literacy Learning of Deaf and Hearing Preschoolers in a Sign Bilingual, Coenrollment Setting in Hong Kong |url=https://muse.jhu.edu/article/847513 |journal=American Annals of the Deaf |language=en |volume=166 |issue=4 |pages=527–553 |doi=10.1353/aad.2021.0034 |issn=1543-0375}}</ref> The Quota International organization with headquarters in the United States provided immense educational support in the Philippines, where it started providing free education to deaf children in the Leganes Resource Center for the Deaf. The Sounds Seekers British organization also provided support by offering audiology maintenance technology, to better assist those who are deaf in hard-to-reach places. The Nippon Foundation also supports deaf students at Gallaudet University and the National Technical Institute for the Deaf, through sponsoring international scholarships programs to encourage students to become future leaders in the deaf community. The more aid these organizations give to the deaf people, the more opportunities and resources disabled people must speak up about their struggles and goals that they aim to achieve. When more people understand how to leverage their privilege for the marginalized groups in the community, then we can build a more inclusive and tolerant environment for the generations that are yet to come.<ref name="padden2005" /><ref name="bigD" />

== History ==
{{Main|Deaf history}}
The first known record of [[History of sign language|sign language in history]] comes from [[Plato]]'s [[Cratylus (dialogue)|Cratylus]], written in the fifth century BCE. In a dialogue on the "correctness of names", [[Socrates]] says, "Suppose that we had no voice or tongue, and wanted to communicate with one another, should we not, like the deaf and dumb, make signs with the hands and head and the rest of the body?"<ref>{{Cite web|title=Cratylus, by Plato|url=https://www.gutenberg.org/files/1616/1616-h/1616-h.htm|access-date=2022-02-05|website=gutenberg.org}}</ref> His belief that deaf people possessed an innate intelligence for language put him at odds with his student [[Aristotle]], who said, "Those who are born deaf all become senseless and incapable of reason," and that "it is impossible to reason without the ability to hear".

This pronouncement would reverberate through the ages and it was not until the 17th century when manual alphabets began to emerge, as did various treatises on [[deaf education]], such as ''Reducción de las letras y arte para enseñar a hablar a los mudos'' ('Reduction of letters and art for teaching mute people to speak'), written by [[Juan Pablo Bonet]] in Madrid in 1620, and ''Didascalocophus, or, The deaf and dumb mans tutor'', written by [[George Dalgarno]] in 1680.

In 1760, French philanthropic educator [[Charles-Michel de l'Épée]] opened the [[Institut National de Jeunes Sourds de Paris|world's first free school for the deaf]]. The school won approval for government funding in 1791 and became known as the "Institution Nationale des Sourds-Muets à Paris."<ref>{{Cite web|title=Institut National de Jeunes Sourds de Paris|url=https://www.injs-paris.fr/sites/www.injs-paris.fr/files/linjs_de_paris_-historique.pdf}}</ref> The school inspired the opening of what is today known as the [[American School for the Deaf]], the oldest permanent school for the deaf in the United States, and indirectly, [[Gallaudet University]], the world's first school for the advanced education of the deaf and hard of hearing, and to date, the only higher education institution in which all programs and services are specifically designed to accommodate deaf and hard of hearing students.

== See also ==
* [[Causes of hearing loss]]
* [[Deaf culture]]
* [[Deaf education]]
* [[Deaf history]]
* [[History of sign language]]
* [[Hearing loss]]
* [[Models of deafness]]
* [[World Hearing Day]]

== References ==
{{Reflist}}

==External links==

* [https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss WHO fact sheet on deafness and hearing loss]
* [[wikiversity:Global_Audiology|Global audiology]], [[International Society of Audiology]]
* [[wikiversity:International_Ototoxicity_Management_Group_(IOMG)|International Ototoxicity Management Group]]

{{Ear symptoms and signs}}
{{Authority control}}

{{DEFAULTSORT:Deafness}}
[[Category:Deafness]]
[[Category:Hearing loss]]
[[Category:Audiology]]
[[Category:Broad-concept articles]]