Ukulahlekelwa Ikhono Lokuva Amaziko Aphakamileyo
Abantu abanokulahlekelwa kwindlebe ephakamileyo kakhulu abakwazi ukuva izandi kwii-frequencies eziphezulu, ezifana nezandi ezifana neileta, h no-f. Oku kungenza kube nzima kuwe ukuqonda intetho.
Kwi- audiogram , ii-frequencies zihamba ukusuka kwii-frequencies eziphantsi . Inkcazo yevolumu ephakamileyo iyahluka. Ezinye iingcali zibhekisela kwi-2000 i-Hertz (2kHz) ukuba iphakamileyo.
Amanqanaba aphezulu avela kwi-Hertz ukuya ku-8000 iHertz. (1000 Hz ithathwa njengowamaxesha aphindaphindiweyo.)
Sibanzi
Ukulahlekelwa kweendlebe eziphezulu ukuphazamiseka komntu ukuqonda intetho. Oku kwenzeka ngenxa yokuba iinconta (s, h, f) zivakala izandi eziphezulu ezivela kwi-1,500 ukuya kuma-6,000 eHertz. Ukuphulaphulwa kweendleko kwii-frequencies kuthetha ukuba ezo zandi ziyanzima ukuqonda. Kubantwana, oku kunokuthetha impembelelo embi kwimfundo yabo ngenxa yokungakwazi ukuthetha intetho eklasini.
Izinga lomngcipheko
Ngomzamo wokufumanisa ukuba baninzi abantu abanolu hlobo lokulahlekelwa kwindlebe , abaphandi bafanisa idatha ukusuka kwi-1959-1962 Isifundo seMviwo seZwelonke seMpilo kwiNkcazo evela kwi-National Health and Nutrition Examination Study (1999-2004). Ukusebenzisa uhlalutyo lwamanani, bafumene ukuba abantu abadala bexesha elifutshane bava kakuhle xa kuthelekiswa nabantu abadala ekufundeni abadala.
Kuhlolisiso lwabaselula, abaphandi baqhathanisa idatha ukusuka kwiSithathu yeSizwe yeMpilo kunye noPhando lweZondlo (i-NHANES) ngo-1988-1994, kwidatha evela ku-2005-2006 i-NHANES uphando.
Bonke abathathi-nxaxheba babe-12 ukuya kwe-19 ubudala.
Abaphandi bafumanisa ukuba ukusuka ngo-2005 ukuya ku-2006, ukulahlekelwa kweentlanganiso ezingaqhelekanga kwakuqhelekileyo kwaye ukulahlekelwa kwindlebe ephakamileyo kakhulu kwakusasazeka phakathi kwabaselula kunokuba kuthelekiswe nentsha eyayifundwa ngasekupheleni kweminyaka yama-1980 nakwi-90s yokuqala. (Abaphandi bachaza ukuvama kwe-3000 ukuya ku-8000 i-Hertz.) Ukusabalalisa ukulahlekelwa kwindlebe ephakamileyo kwamanye ama-12,8 ekhulwini kwiqela langaphambili; kodwa ukususela ngo-2005 ukuya ku-2006, bekuyi-16,4 ekhulwini.
Oku kwakucatshangelwa ukuba "kuphakamileyo kakhulu" ngabaphandi.
Kuhlalutyo lwabo, abaphandi abafumani naluphi na umahluko kumanqanaba okubonakalisa ingxolo phakathi kwale mibini yophando kodwa bachaza ukuba abantwana abaselula bayathandana nokunyaniseka kwinqanaba labo lokubhenca ingxolo. Ngoko ke, ukuxhamla ukulahlekelwa kwindlebe ephakamileyo ephakamileyo kwintlekele kungabonakalisa ukwanda kweso sandi, okubangelwa ukulahlekelwa kweendlebe ezibangelwa ingxolo .
Izizathu
Umsindo awuyena nje umphumo wokulahlekelwa kwindlebe ephezulu. Zininzi ezibangela. Izizathu zibandakanya ukuguga (presbycusis), i-genetics, i- ototoxicity (njengezidakamizwa zamakhemikhali) kunye nezifo kunye ne-syndromes. Kukho ukukhankanywa ukuba kukho izizathu ezifana nesifo sikashukela.
Thintelo
Kukho iindlela zokuthintela ukulahlekelwa kwindlebe ephezulu. Abantu abachaphazelekayo ngengozi banokuqwalasela iindlela ezahlukeneyo zokukhusela ukuvalelwa, njengemikhankaso.
Lawulo
Izixhobo zokuvalelwa ziyakwazi ukuthabatha imisindo ephakamileyo yezandi kunye nokuyinciphisa. Kukho iindlela ezimbini ezahlukeneyo zokwenza oku. Indlela yokuqala, ebizwa ngokuba yi-frequency transposition, ithatha amandla aphezulu aphindaphindiweyo kwaye ibangele kwi-frequency frequency, ekhokelela ekuxubeni isandi esicatshulwayo (eshukumisiweyo) kunye nesandi esicatshulwa esezantsi.
Ngenye indlela, ebizwa ngokuba yi-nonlinear frequency compress, isebenzisa ubungqina bokunciphisa kwisandi esiphakamileyo sokuvakala ukuba uyinciphise, kodwa ayiyikuyihambisa, ngaloo ndlela igweme ukuxubana namaxesha aphantsi. Ukuba ukholelwa ukuba ulahlekelwa yintetho yalolu hlobo, ukubona i- audiologist ibalulekile.
Unyango
Ukulahlekelwa kwindlebe ephakamileyo ephezulu kunokulawulwa ngokusebenzisa izixhobo zokuvalelwa kunye nezimpembelelo ze-cochlear . Ewe, ukufunda ulwimi lwezandla kunye nezakhono zokufunda ngokuphambukayo kunokukunceda.
Imithombo:
Amazwe aseMelika ayava ngokulungileyo okanye angcono namhlanje ngokuthelekiswa neminyaka engama-40 e-Ago: Ukuvalelwa kweNqanaba lokuThuthukisa kwiMveli yabantu abangabakhululekileyo baseUnited States, ngo-1959-1962 no-1999-2004. Indlebe Nokuva. Disemba 2010 - Umqulu 31 - Issue 6 - iphe 725-734
Ukukhubazeka okuphuhlisayo: Ukuvalelwa kokulahlekelwa. Amacandelo okuLawula nokuKhuselwa kwezifo. http://www.cdc.gov/ncbddd/dd/hi2.htm
Glista, uDanielle MSc; USusan Scollie, i-PhD; Melissa Polonenko, MCISc; kunye noJacob Sulkers, BA. Uthelekiso lweNtsebenzo kubantwana abaneNkqubo zoLondolozo lweeNkcitho zeNdinal frequency. Ukuvavanya. Novemba 2009.
UShargorodsky, uJosef, uSharon G. Curhan, uGary C. Curhan, uRoland Eavey. Utshintsho kwi-Prevalence of hearing Loss in US Adolescents JAMA. 2010; 304 (7): 772-778.
USimpson, A. Izixhobo zokuhlawulela amaxesha amaninzi ekulawuleni ukulahlekelwa kwindlebe ephakamileyo: ukuhlaziywa. 2009 Juni; 13 (2): 87-106.