t"fARY BARKER, i\'IS. Ji\?>JF OPIE ... Pallcnls imlll.lIllCd al a younger age amt IhO!le with smalla ... nf dc:.fness: I implanled al age 60 and I impbntcd at age 30.
THE EFFECT OF LONG-TERM DEAFNESS ON SPEECH RECOGNITION IN POSTLINGUALLY DEAFENED ADULT CLARION@COCHLEAR IMPLANT USERS LiSA GEIER,
MA
t"fARY BARKER, i\'IS
Ji\?>JF OPIE, PIID
Lduh pustlingually deale.ned ('LARION~ Multi-StrategyH' Cochlcilf Implanl users. Spt,cch rcco~nilil,n le~..s (eu> sentences ami NUt> WOlf/is) were atlmillislcre,llo 202 ;;OIL~ccUlively implanhtd :ldllll"'- pccopt:ralivcly :uul al ) and t. mOlllh", arlcr inilial dcviCl:: fiuing. Pallcnls imlll.lIllCd al a younger age amt IhO!le with smalla pcru:nlages (lrthcir 'i~es with (kafne:o:..~ achkved ttle highi?'" lev~h of SllllM·tCnll poSl.OPCf:lliw spcc;;h fec0J;fllunll. 1';t!tenIS who had be_en dl.'.affor ~60'l. l)f lheir Ii"'e_~ lkmonstf31cd a slower r31('_ of l>"JlCCCh recl)gnilioo impro\'clIll"nllh3Jl tb"Sl' whb sborler .lllr.lliOIl~I,r deafne"'-"", hill slill cQlIIinlicl1 to impflOYc Wilh incl'('as... d iml'l"fIIl.·.",pcriencc. KEY \VORDS· . ;llHtHftly depti\;)tion, auditory pwslhesis. (ochkat implant, lrllfation of ,teafne~s. ~Ixwch recognition,
IN·rRODUCrION
guisl,IC ahilities, or Ihe abilily chle..n impl:lI11.
Rescarch h..~ demOllSlraled Ihal age "I implanlation ~nd duration of dt;Olfnc-"s hav~ significant effecfs on posloperative perfomlancc ofpo:'>llingu:llly deafencd adul! cochlear impltllll reeipients. l -4 Bolh poSIopcr:llive spe~ch recognilion perfnnnanec and the r,He (If improvement in performance over time apPC;lT 10 be lower ami slowcr in persons whu are (kaf for:t longcrp'~rioclof lime and/or who arc (ll~'erwhcn implanted. Ilowcvc-r, it is nor t.:Ie;lr from previous rcscarch whal Ihe independent contrihulions of duration of de indjeatl~ thai duration (If deafness
a..114
rn'l'p('II) Pn:"r ClO. abe:ll impl:lnl
.skpl SIcp2
Total Rcgr.::ssion :II ~tl':P .>
·I"coI:.1 Rcgn-ssll>n al Step "' R til
I'
R
,!f
.fM.101
0.9)2
(3. I?R)
F.. 12.PI7
P
_-_._~--------
0.374 C...crficU-JlI,s.:l1
0. 19ln SICll
10.12
J p
RrM
Preop ('ID Age 31 implanlalk\ll % of life t1~3f
.oml
.. _--_ .._--_._-0.20.') -0.201 -0.279
:uno
-3.021 -4.2001
.002 .CX)} .0001
signific:l.Iltly afft:cts the over:1l1lcvel of poslimplanlatinn speech n;l.:ogniliun pcrfommncc. The mrc of improvemcnr in speech rccognilion _.:rformancc is an issue Ihal also may be relmcd 10 duration of deafness an~1 age:'ll implimtalioll. PaliclJ(s achieve Iheir maximum spcel.:h Ikrfonmlllcc levels 011 differenl limes after impl:mlation. For example, Locb and Kessler' repol1ed lhat of the first 4Cl palienls to n:ccive Ihe CLARJON@ Muhj-SlmtegyTM Cochlt:;lr Implanl. over half (59%) reached a plaleall in speech perce pI ion pcrfonnancc afler only 3 months of implant experience. In contrast, lhe other 4 t % of the suhjecls eOlllinucd to show impwvement at variahlc rates. Tyler and Summerfield] also dcm0nslrated Ihal parients had various rales of improvement in perf0nllaflcc Over lime. Notably. patients who did 110/ demollstrate ~nefit by 30 to 36 months after implantation tended nul to show lIICTcases in scores even after 60 months of device usc. Clearly, some patients show potential for benefit from an implam carlyon. Olhers require greater experienl.:e -·'jth Ihe implanl 1o demonstrate benefil. 6 The rea~Jns for differential nlles of postimplant perfonnance improvements are unclear. but the rate of improvement may be relaled 10 dllnllioll of deafness.
Therefore. the purpose (If Ihis sludy was lhreefold. First. the effcct of duration of deafness·~ expressed :IS percenlage (If life wilh deafness - independent of age at implanlalion on 6-molllh ~)()SI0p enuive speech recognition performance in adult Clarion users was examined. Second. llle ralC of change of posloperJlivc speech pcn;cplion scores over 1111..' firsl YC:lr of implanl use \Va." examined as a function of lhe same vMbbles. It was expected that :l longer dur:uiOIl of deafness and an older age at implantation would result in poorer pcrfonnance at 6 months after implantarion and a slower rate of Improvcment. Third. Ihe effecr of duration of ileafne.'\s - expressed itS pcrcent::lgc of life wilh deaf-
BC'/o Prcop elD Age :ll iTllplanl;;Iion 'i. u( tife deaf
0.1f,7
-f).HS -o.J1I7
p 2.526 -.1.551 -4.f,78
.012 .0001 .lIOnl
ness - on rate of speech performance improvcment w,lscxamined individually in patil':nls who had hel':n de."lf for ovcr 60% of Iheir lives prior 10 receiving an implant to dCfcnnine whcther alJdilory dCprivillioll of that magniltlde consislclllly rcsulls in slow rates of posluperalive improvemenl. MEn·IODS Subjt:C1J. Tht..' subjcl.:IS wcrl': 202 posllingually deafened aduhs 'fUpl::lIlled oclwecn March 1991 and August 1996 durin~ lhe dinicall';"! of the Clarion 1.0 and 1.2 devices. Palienls used eilher the 1.0 or 1.2 spcel:h pJ()ce.~sor. Approximately 90 0!n of the patients utili:tt:d the Continuous Intt:rleaved Sampler (CIS) processing Slrrltegy. while (he olher 10% used the ('omprcsst:d Analog (CA) strategy. Pnmary palienl selection ~;riteria included profound deafness hilatcrally (rlm~ lOne average;;;: 90 dB hearing level), ncgligibk heming :,id henent (520% correl.:t CI D sentence score and 51 0% NU6 word swrc), and postlingual onset of profound de::lfness (onset at6 years of age or older).
Procedures. The OD senlences and NU6 words from Ihe MinimalAudilory C,tpabililies (MAC) battery were llse and NU6.sl:ore.", the 2 variable." were entered into 2 multivariate regression an.aly::es.l'he predicti ve w"tribulion of preoperative score!' al."" was examined in the regression an:..ly:-es. Each predinnr was enlered inlu the aU:llysis in a slel'wise l";L"hion in that after c:lch predil:lur wa~ enlered. the chnnge in R2 was examined to determine if more predictors could be added. Preoperalive scores were entered first followed by age nt irnplnnlation and, finally, hy percentage of life with etCil f nt~s~.
S
