CA2018732C - Ear wax barrier and acoustic attenuator for hearing aid - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A barrier for a hearing aid that combines the feature of both (1) preventing ear wax from contacting and damaging the internal components of a hearing aid or hearing aid receiver and (2) variably dampening the acoustic response of the hearing aid.
The barrier includes, in combination, a housing defining a central axis of passage, as well as a plurality of projections and a screen. The projections extend inwardly from the interior surface of the housing, each projection partially occluding the cross-sectional area of the housing. The projections provide a tortuous path for ear wax migrating into the hearing aid, and the screen provides additional area for wax accumulation. The projections and screen also dampen or otherwise modify the frequency response of the hearing aid. The screen may also be interchanged or adjusted to accommodate the specific frequency attenuation needs of a particular user.

Description

The subject matter of thls applicatlon is related to the sub~ect matter of Canadlan patent application Serial No. 563,865 filed April 12, 1988.

2~ ~732 BAC~Ç~O~NILOP .~VE~
1 Introduction The pr-~ent lnventlon relatss generally to ear wax b~rriers and aoou-ttc attenuator~ Mor- partlcularly, the s lnv-ntlon r-late- to a barri-r that reduce- th- amount o~ ear wax that m~y nt-r th- ~ound chann-l o~ a h-arlng ald d-vlc-, ouch a~
"ln-the-sar" or "canal~ type hearlng ald- or acou~tlcal r-eonator-, and that may ~urth-r~or- rr-ctlv-ly modlry th-~r-qu-noy ro~pon-- o~ th- h-arlng ald d-vla-Mo~t h-arlng ald- lnalud- à hou-lng, or ~h-ll, that hold~ th- aompon-nt- o~ th- ald Th- h-ll Or any ald- ar-d-elgn-d to r-~t wlthln th- ar ¢anal o~ a u--r Th- ~h-ll o~ an l-ctronla h-arlng ald ay hold, ~or xampl-, a mlcrophon-, ampll~lcatlon olr¢ultry, and a r-c-lv-r Th- ~lcrophon- 1-xpo~ed to eound lgnal- tro~ out-ld- o~ th- ald and r--pon~lv-ly cr-at-- an el-ctrlcal lgnal Th- l-ctrlcal lgnal ~ay be -nt to the ampll~ylng clrcultry or oth-r l-ctrlcal ald co~pon-nt~
Such aompon-nt~, ln turn, eupply a algnal to th- r-c-lv-r, and th- r-c-lv-r r-~ponelv-ly cr-at-a eound In many el-atronla h-arlng àlde, th- Round trav-l~ ~rou an output port o~ th- r-a-lv-r, through a ~ound ahannel ln the ald, and out of th- ald through an output port ln th- ~holl o~
the ald The eound ~rom the ~hell output port may then travel through the u~er's ear canal and cause the ear drum to vibrate Tha ear~ o~ mo~ heartng ald users naturally ~ecrete a ~ub~tance re~srred to a~ cerumen or ar wax Whlle the ear wax A~EGPETTI A WITCOFF L~D
tO SOLITI~ WACKE~ D~IVE
CI~IC~OO IWNO~S ~
TELEP~ONE (~ IODO

2~ ~732 cl-an- the lnternal tructur- o~ an ar, lt al-o tond~ to ~low lnto the ound channel and recelver o~ the hearlng ald Upon ent-rlng th- rec-lv-r, th- ar wax lnter~-r-- wlth, or pr-v-nt-, the proper operatlon o~ the rec-lver s Small, co~metlc "ln-th---ar" ald- and ~canal" alds ~whlch typlcally lay at lea~t partlally wlthln th- us-r~ ar canal) have now be-n d-v-loped Wlth uch ald-, how-v-r, th-phyeical volum- in-ld- o~ th- h-arlng ald avallable ~or ¢ompon-nte 1~ r-duced Thl- 1- partloularly tru-, ~or exaupl-, wh-n th- lnterlor o~ th- u~-r'~ ~ar 1~ r-latlv-ly ~all Furth-rnor-, th- t-ahnology a--oclat-d wlth h-arlng ald ~anu~aatur- ~r-gu-ntly lnvolv-- ~abrlcatlng th- h-ll out Or pla~tlc The hell 1- contour-d to th- hap- o~ the lnn-r ~ur~ace o~ th- ar Th- thlcXn--- o~ th- h-ll lo dlctat-d by th- r-qulr-~-nt that th- h-ll phy-lcally nalntaln lt- etru¢tural lnt-grlty and prot-ct th- ald oo~pon-nt- ln-ld- Th- wall thlckn-e~ o~ th- ~h-ll, how v-r, r-duc-- th- phy-lcal volu~e lneid- th- h-arlng ald avallabl- ~or co~pon-nt- Th- r-duced volu~- lncr-a--- th- n--d rOr a ~-an- ~or att-nuatlng eound ~lgnal- wlth ~all-r co~pon-nt~
Th- r--ultlng ll~lt-d ~pac- wlthln tho h-arlng ald avallabl- rOr aonpon-nte g-n-rally r-gulr-e that th- r-c-lv-r b-poeltlon-d ae d--p ae po~albl- ln th- ueer'e canal How-v-r, euch po~ltlonlng o~ the hearlng ald wlthln the canal brlng~ the recelver output port lnto closer proxl~lty to the ar canal ~UEGFIETTI ~ WITCOFF. ~-~
10 SOUTH WACKEP. OF~IVE
CHlCAaO IL~IW15 ~0-TE~EPHONE 1312~ .IODO

2 ~ 3 2 envlronment containlng the wax-senQratlng tl~u- ln~ld- th- ear canal rrhu~ whlle the lntroductlon Or ln-the-ear and canal ald~ has lmproved th- acceptana- o~ h-arlng ald- by th- h-arlng-lmpalred publlc, such hearlng ald~ hav- created proble~s a~oclated wlth smaller component~ and qreater ear wax bulld up wlthln the hearlng ald Each o~ th-se two probl-a- 18 dlBCU~ed below 2 Wax Mlgratlon--Prlor Art A~ tho~- Or th- ordlnary ~Xlll ln th~ art wlll ac~nowl-dge, ar wax ~lgratlon ha- b--n r-cognlz-d a- a dlrrlcult problom ~h- ~lgratlon of wax lnto th- ~ound channel and r-c-lv-r Or h-arlng ald~ ~ub~tantlally lncr-a--~ the ~u~a-ptiblllty o~ ~any r-c-lv-ro to clogglng Th- progre~oiv-, gradual clogglng Or th- r-c-lv-r r-~ult~ ln th- reductlon o~
acou~tlc galn and ln pow-r output by th- r-c-lver, ~ometlmo~
cul~lnating ln th- ao~pl-t- railur- Or th- aid to provlde ampllrl-d ~ound Th- d-gradation or ~allur- Or p-rroroanc- Or th- ald 1~
annoylng to th- u--r Wh-n wax bloa~ag- occur~, the h-arlng ald may r-qulr- co~pl-t- dl~a~o-mbly ~o that th- r-c-lv-r may be cl-an-d or r-plac-d or cour--, brlnging the h-arlng ald to a ~ervlc- c-nt-r ror dl-ae--mbly and po~lbl- roplac-m-nt o~' th-rocelver 1- both lnconv-nlent and xpen~lve rOr the user A numb-r Or preo-ntly avallable sy~tems are poorly suited to guard agalnst ear wax bulldup in the receiver of a ALLEt~llErrl 3 WITCOFF. LrD
10 SOLlrt WACKER DllIVE
C141CA(10. ILLINOIS
r~.!LEPuONE ~312\ ~

2~8732 hearlng ald Some "barrier" de~lgn~ u~e a ~lne mesh ~creen ln the sound channel between the r-ceiver and the out~lde o~ the hearlng ald Such ~cr-en~ ~uff-r ~ro7n the de~lclQncy, however, that lr the ~creon ~lz- 1- made urrlcl-ntly mall to protoct the recelver ~rom wax mlgratlon, the ~creon holo- will eventually be clogged by the wax When mesh 1~ made more coaroe, however, wax ; wlll not be a~ ef~ectlvely prevented rrom mlgratlng acro~ the creen barrl~r to th~ r-c-iv-r Oth-r ~y~t-m- ~or pr-v-ntlng wax mlgratlon lnto a r-a-iv~r lnclud- provldlnq ~ lngl- ap-rtur-, o~ a emall oro~-~-ctlonal ar-a, b-tw--n th- r-c-lv-r and th- out-ld- Or th- ald Othor ~yot-m- lnvolv- th- r-placem-nt or a c-llular ynth-tlc mat-rlal b-tw--n th- r-c-lv-r and out~ld- Or th- ald 8uch de~lgn~ Ort-n urr-r rrom th- ~am- d-rlcl-ncy Or not slmultaneoud y achlovlng both a long-t-r~ barrlor to wax mlgratlon and etlll pr-v-ntlng th- clogglng Or wax ov-r th- llr-Or th- ald 9uch porou~ barrl-r-, thu~, g-n-rally r--ult ln an un~atleractory trad--orr b-tu -n r--l-tanc- to wax clogglng Or th- barrl-r lt~ , on th- on- hand, and th- pr-v-ntlon o~ wax mlgratlon lnto th- r-c-lv-r on tho oth-r Whll- a ~mall ap-rture barrler may prevent wax mlgratlon, lt wlll al~o clog Large apertur-s may not clog, but they al~o wlll not be a~ errectlve ln blocking wax Small pore barrl-r- plac-d ln th- pathway b-twoon the receiver and the output port o~ the hearlng aid may cau~e ., ~ .

A~E~RETTI a WITCOFF L-D
10 SOUTI~ WlCKER DRIVE
Ct IC/~CO, IL~IN015 00~
TELER~O~E ~31~ 7~0D0 2 ~ 7 3 2 lncrea~ed acoustlc impedance Increased lmpedance may result ln an unde~lred change ln the freguency response ln output pressurQ
levels dellvered by the recelver Whlle lt may o~ten be de-lrabl~ to modlfy th- ~reguency respon~e Or a hearlng ald ln order to better meet the needs Or a partlcular hearlng ald user, 3uch modiflcatlon hould not occur haphazardly because o~ wax bulldup Planned modl~lcatlon Or the ~reguency re-ponoe, how-ver, o~ten lnvolv-- dl~a--embllng the aid and alt-rlng the lnt-rnal ~tructure o~ the ald 3 Acou-tla Att-nuatlon--/l Prlor Art a- 1- al-o r-cognlz-d by tho-- o~ ordlnary klll ln th-art, lt 1~ o~t-n advantag-ou- and d--lrabl- to mooth out th-p-ak~ ln th- r-c-lv-r r--pon-- charact-rl~tlc-, and oth-rwl--att-nuat- th- acou-tlc r--pon-- ot an ald 8--, ~or xanpl-, th-damped and undanp-d r-c-lv-r output charact-rl-tlc~ ~hown ln Flgur- 1 Such att-nuatlon may lmprov- th- ound guallty o~ th-ald and thua lmprov- th- ua-~uln-aa o~ th- ald to th- hearlng i~palr-d So~- prlor art d-vlc--, for xampl-, u~- a barrl-r ln~-rt-d ln a h-arlng ald ~ound pa~ag-way dl~tal ~rom th-r-c-lv-r output port Th- barrl-r may con-l-t o~ a porou~
el-ment, provldlng a ~lxed acou-tlc re~pon-- Such a barrl-r may smooth out the peaks o~ the ~reguency response o~ a hearlng ald r-c-lver ln a ~ub-tantlally ~lxed, non-varylng manner How-ver, many such elements are not easlly removed and replaced ln the ALLE~3FIE~l ~ wlTCOFF L~l 10 SOUTN WACKEP, DPIVE
CtllCAaO. ILUNOIS ~
TELEP~ONE ~2) 7-5-10Y

2 ~ 2 ~leld, nor are the damping characteristic~ o~ the barriar ea~ily altered As iB recognized ~n the art, variable da~ping 18 o~ten de~irable to accommodate the requirement o~ persons with dif~erent hearlng regulrement~ and lmpalrments A1QO~ lt ls o~ten de~lxable for a tralned h-arlng aid dlopen~er (and not the hearlng aid u~er) to ad~u~t th- damplng characterl~tic~ o~ ~uch a barrl-r and to cl-ar th- ald Or xc--- wax bullt u~ wlthin th-ald Th- ablllty to ad~u~t th- h-arlng ald ~r-qu-ncy r-epon-- ln the rl-ld 1- partlcularly lnportant, ~lnc- dlrr-r-nt w-ar-re r-qulr- dlrr-r-nt rr-qu-ncy r--pon-- charact-rletlc-, and euch charact-rl~tlc~ Jo-t rr-quently cannot b- d-t-rmln-d ln advanc- The characterletic- can ~r-gu-ntly only b- d-termlned baa-d on th- actual xp-rl-nc- or th- w-ar-r Th- ald dl-pen~-r mu~t b- abl~ to ad~u-t th- rr-qu-ncy r--pon-- Or th- ald ln th-rl-ld ror proper op-ratlon Or th- ald Thu-, lt 1- d-elrabl- ~or a lngl- unlt to provld- th-tworold runctlon Or provldlng variabl- acouatlc damplnq and bloc~lng pot-ntlally har~ul ar wax Mor-ov-r, ~uoh a d-vlc-, whlch oombin-- both r-atur--, hould almultan-oualy allow easy ad~u~tm-nt and removal by a hearlng ald dl~pen~er ~LLEGRETT~ ~ wlTCOFF LID
tO SOUTII WACKE~ Of IIVE
Cl~ICAGO, IWNOI~I
TELEI'HONE /~ 7-~

. .

2~1g732 8UMMARY O~_ID~ YENT~QN
A prlnclpal aepect of the preeent lnvention le a barrler for a hearing ald For lllustratlve purposee, the inv~ntion i~ particularly deEwribed hereln ae used with an electronlc hearing ald However, thoee e~llled ln the art wlll under~tand that the lnvention aleo 18 u~eful wlth acoustlcal reeonator~, acou~tical hearlng ald-, and ln oth-r ear-r-lat-d apparatu~ whlch would bene~lt ~rom a elmllar barrler The hearlng ald ln¢lud-- a ehell and a reoelv-r wlthln the eh~ oth th- ehell and rec-lvar lnclud- an aoou~tlc output port The barrler lnolude~ a houelng wlth a plurallty of pro~-ctlon- The hou-lng lnt-rconnecte the acou-tlc output port-ot the recelver and ehell The houslng deflnee ~n lnterlor ~ur~ac- and a central axl- Or paeeaq- betw--n ald two ende ot th- houelng Th- pro~-ctlon- may b- dl-placed ~rom ach other ~oth extend lnwardly ~rom th- lnt-rlor eurrace of th- houelng Each pro~ect~on partlally occludee a portlon o~ the hou~lng lnterlor Coneequently, the pro~ectlone provlde a tortuou- path ~or eolld or eemlllgyld oar wax mlgratlng axlally along the lneld- of th-houelng Moreov-r, the barrler may furth0r lnclude a varlable acoustlc attonuator The varlable attenuator and pro~ectlone cooperatlvely de~lne mean~ to dampen or otherwiee modlfy the frequency reepon~e of the hearing aid A~EORE~I ~ WITCOFF. L~D
SOUTH WACKER DRIVE
CHICAOO. IELIHOIB ~0J
~E~EFHOIIe (J~2~ r~

20~73~

Thu~, an ob~ect of the present lnvention i8 an lmproved ear wax barrler for a hearlng ald Another ob~eet 1~ an lmproved acouotic attenuator ~or a he~ring ~id still anoth-r ob~ect 1-an lmproved acou~tlc attenuator ln comblnatlon wlth an lmproved e~r wax barrler Another ob~ect of the present lnvention ls a barrl-r that more effectlvely re~l~t~ wax clogglng Still another ob~ect le a barrler that mor- ~ub~t~ntlally block- th- mlgratlon of naturally oeeurrlng ar wax, th-r-by r-duelng th- clog~lng of a h-arlng ald r-a-lv-r 8tlll furth-r ob~-ot 1- a barrl-r that pr-a-nta 1--- aeou-tl¢ l~p-dane- to a r-e-lv-r wh-n plac-d b-tw--n th- r-e-lv-r and th- acou-tlo xlt port o~ th- h-arlng ald Anoth-r ob~-ct 1- a barrl-r that coll-ct- wax and n--d not b- el-an-d nor chang-d a- fr-qu-ntly ov-r th- llf- of th-hearlng ald Anoth-r ob~-ot 1- a ~ax barrl-r that 1~ ln-xp-n-lv-to mak- and malntaln, th-r by low-rlng th- coet of h-arlng ald~
~or eonauo-r-Stlll a furth-r ob~-¢t le a barrl-r that mor-pr-dletably ~odl~l-a th- ~r-gy-ney r--pon-- o~ th- h-arlng ald ! Anoth-r ob~-et 1- a barrl-r that ~or- a~lly allow- aa~u~t~ent of th- aeou-tle damplng o~ th- h-arlng ald r-e-lv-r output ln th-fl-ld 8tlll another ob~ect 1~ a barrl-r that le mor- eaelly removed ln the fl-ld ~or r-plae-m-nt or ad~ustment ~hu~, of cour~e, lt i9 an overall ob~-ct of the pre~ent inventlon to provide an apparntus whlch combine~ both a mor- ef~e¢tlve ear wax AUEGRFTTI ~ WITCOFF LID
~O S'OUT~1 W~CKER Di~lVE
C 1 CAGO ILLlN
TELEPHO~IE ~

2~ ~ ~7 32 61368-879 barrier and a variable acouRtic attenuator that is eaAier to adjust and remove in the field.
In summary, the present invention provides a barrier for a hearing aid, said hearing aid including a shell having an acoustical outlet and a receiver positioned within qaid shell, said receiver having a receiver outlet port and emitting ~ound that partially define~ an acou~tic respon~e for ~aid hearing ald, compri~ing~ in combination:
a housing adapted to be recelved by said ~hell, ~aid hou~lng including a central acoustical pa~ageway linking said acou~tical outlet and said receiver outlet port, ~aid central acou~tical pa~sageway being defined by an interior wall surface of qaid housing and sub~tantially defining a central axis;
at lea~t two projection~ within ~aid central acoustical pa~sageway, said projection~ being ~patially and angularly di~placed with respect to said central axi~ and cooperating to occlude a linear path through said central acou~tical pas~ageway, ~aid two projection~ being 3ub~tantially perpendicular to ~ald central axi~
said pro~ection~ cooperatively defining trap means for providing wax accumulation ~ite~ within ~aid hou~ing, whereby migration of ear wax into said hearing aid is substantially retarded: and an acoustic attenuator, said acoustic attenuator and projections co~peratively defining means for damping ~aid . ~

: 2 0 ~ 8 7 3 2 61368-879 acoustic respon~e of said hearing aid, said acoustic attenuator including a screen mesh for damping said acoustic response of said hearing aid, said screen mesh being comprised of substantially S parallel wire strands arranged substantially in a single plane, i said plane of said screen mesh being substantially perpendicular to sald central axis, whereby said wire ~trand~ of ~aid 9creen mesh partially occlude said central pa~ageway and define additional trap means, providing further wax accumulation sites within said housing.
According to another aspect, the invention provides a barrier for a hearing aid, said hearing aid including a shell having an acoustical outlet and a receiver positioned within said shell, said receiver having a receiver outlet port and emitting sound that partially defines an acoustic response for said hearing aid, comprising, in combination:
a hou~ing adapted to be received by ~aid shell~ said housing including a central acoustical passageway linking said acoustical outlet and said receiver outlet port, said central acoustical passageway being defined by an interior wall surface of said housing and substantially defining a central axis;
at least two projections within said central acoustical passageway, said projections being spatially and angularly displaced with respect to said central axis and cooperating to occlude a linear path through said central - lOa acoustical pas~ageway, said two projections being substantially perpendicular to said central axis, said projections cooperatively defining trap means for providing wax accumulation sites within said housing, said wax accumulation sites cooperatively extending completely about said interior wall surface, whereby migration of ear wax into said hearing aid i9 substantlally retarded, said projections includlng lnterdigltated ribs extending substantially parallel to said central axls to further impede tha 10w of wax between adjàcent projections: and a variable acoustic attenuator, said variable acoustic attenuator and said projections cooperatively defining means for damping said acoustic response of said hearing aid.

- lOb -~ .~

BRI~F DESCR~pTION OF THE DR~ Ç
A preferred embodiment o~ the present lnvention lo deocrlbed herein with re~erence to the drawing wherein FIGURE 1 iB a graphlcal repreoentation, ~or illuotr~tive purpo~eo only, o~ both da~ped and unda~p-d ~r-quoncy re~pon~e characteristic~ o~ a hearlng aid rec-ivors FIGURE 2 lo a ~ront, partlally cut away vl-w o~ a prior art behlnd-the-ear heârlng ald, ln u~e on a u~er'~ art FIaURE 3 1~ a rlght eid-, partlally aut aw~y vl-w o~ a pr-~err-d embodlD-nt o~ th- pr---nt lnv-ntlon, howlng an ln-th--ar h-arlng ald wlth a barrl-r ln u~- wlthln a u--r'- arJ
FIGURE 3a lo a p-r~p-ctlve, partlally cut away vl-w o~
th- pr-~-rred ~bodl~-nt hown ln FIGURE 3J
FIGURE 4 1- a p-r-p-atlv-, partlal cro---o-ctlonal vl-w o~ the barrl-r ~hown ln FIGU~E 3t FIGURB 5 1~ a p-r-p-atlv-, partlal cro~-o-ctlonal vl-w o~ a ~lrot alternatlv- ~bodlm-nt o~ th- barrl-r ohown ln FIGURE

4~
FIGURE 6 1~ a p-r~p-atlv-, p-rtlal oro~-c-ctlonal vl-w ao 0~ th- pr-~-rr-d ~bodl~-nt ~hown ln FIaURE 5, ehowlng a bulldup o~ ar wax a~t-r th- barrl-r ha~ b--n ln u~- wlthln a h-arlng aldt FIGURE 7 lc a perspectlve, partlal cross-~ectlonal view o~ a ~econd, alternatlve embodlment o~ the barrier shown ln ALLeORETTI ~ WlTt:OFF L~
10 SOUT)I WAC#ER ~1RNE
Cl-ICA~30. I~LI~ 015 ~0~
Tl!LER~IONE ~10 71S-OOO

2~ 8~32 FIGURE 8 1~ a per~pective, partial cro~ ctlonal view o~ a thlrd, alternative embodiment o~ the barrier shown in FIGURE
4s FIGURE 9 1- a p-r~p-ctiv-, partial cros~--ectional vlew Or a ~ourth, ~lt-rnativ- mbodlm-nt Or th- barrl-r hown ln FIGURE 4s FIGURE 10 1~ a perspQctlve, partlal cro~o-sectional vl-w Or a flrth, alternatlve mbodlment o~ the barrler shown ln FICURE 11 i~ a ~ld~ w o~ a ~lXth, alternatlv~
mbodlm-nt Or the pr---nt lnv-ntlont FIGURE 12 1~ a cro~ octlonal vl-w o~ th- barrler ~hown ln FIGURE ll tak-n along lln- 12--12J
FIGURE 13 1- a partlal cro~ -ctlonal, partlal lde lS vl-w o~ a h-arlng ald lllu-tratlng th- barrl-r Or FIGURE 11 lncorporated th-r-lnJ
FIGURE 1~ 1- a top ~l-w o~ th- barrl-r o~ FIGURE llJ
FIGU~E 15 1- a partlal cro-a---¢tlonal, partlal ~ld-vl-w o~ a mold to produa- th- barrl-r o~ FIGUR~
ao FICURE 16 la th- aro-----atlonal vl-W o~ F~aURF 11 illu~tratlng a ~odl~l-d pro~-atlon ~or th- barri-rs FIGU~E 17 1- a partlal top vl-w o~ th- modlrled pro~-ctlon hown ln FIGURE 16~
FIGURES 18a and 18b aro cro~s-sectlonal vl-w~ Or FIGURE
ll lllustratlng the lncorporatlon Or an acou~tlcal ba~le ln an ear wax barrier ALLEoRE7r- a WI~COFF. L-D
~O SOUTH WACKeR DRIVE
cl~lc~ao. ILLINO~S ~0~
reLePHoNe 1~ 7~5 ~000 2~1l g732 FIGURF 19 i8 an enlarged partlal and exploded por~pective vlew o~ the hou~ing and acouE~tlcal bafrlo shown ln FIGURE 18;
FIGURE 20 i~ a cro~ ectlonal vlew or the barrler 5 ~hown ln FIGU~E 11 lllu~tratlng a modl~1-d pro~-ctlon ~or th-barrier FIGURE 20a 1~ a cro~ ectlonal vl-w o~ FIGURE 20 taX-n along the lin- 20a -- 20as FIGURE 21 1~ a cro~ ctlonal vl-w o~ a -aond alt-rnatlv- ~mbodlm-nt ot th- pro~-atlon ~or th- barrl-r hown ln FIGURE 22 1- a partlal cro~ ctlonal vl-w o~ th-barrl-r ~hown ln FIGURE 11 wlth th- ~cr--n o~ FICURE 23 lna-rt-d to ~odl~y th- ar wax barrl-r~
FIGURE 23 lc a p-r-p-ctlv vl-w o~ a ¢r-en u~6d in a further modlflcation o~ th- barri-rs FIGURE 24 1- a top plan vl-w o~ th- ~cr--n ~hown ln FIGURE 25 1~ a p-r-~-ctlv- cro-a-~-ctlonal vl-w o~ a ~tlll ~urth-r uodl~lcatlon o~ th- barrl-r o~ th- pr---nt lnventlont FIGURE 26 1~ a cro~s-~ectlonal vlew o~ th- modl~ication o~ the barrler shown ln FIGURE 25t FIGURE 27 iB a cross-~ectional view of FIGURE 26 taken along the line 27 -- 27 ~L~EGRETTI ~ WITCOFF ~rD
0 SOUTI~ W~CKER ORIVE
C~ CAGO I~INOIS oo505 TE~EF~ONE 1~ 2~ ~ 5 ~OOO

- 2~1~732 FIGURE 28 1~ a cross-~ectlonal view Or the barrier shown ln FIG7JRE 11 lllustrating the use of two separate screene FIG7JRE 29 is a top, partially cut away vlew of the two screen~ along the line 29 -- 29 ehown ln FIGURE 28 wlth the two cr-~n~ ln a orthogon~l r-lat~on~hlp ~nd rurth-r llluetrating how the ~creens ~ay b- rotat-d relative to each other to vary the acouetlc lmp-danc- o~ the ecreene~
FIGURE 30 1~ a top, partlally cut away vl-w o~ th- two aar--ns ~hown ln FIGU~F' 28 wlth the two cr--n~ ln a par~llel 10 relatlonshlp~
FIGURE 31 1~ a p-r-peotlv- vl-w o~ th- two cr--n~
~hown ln FIGURE 28J
FIGURE 32 1- an xplod-d, p-rep-ctlv- vl-w ot y-t anoth-r modl~lcatlon o~ th- barrl-r o~ th- pr---nt lnv-ntlon;
FIGURE 33 1~ a cro~--e-ctlonal vl-w o~ th- ~odl~lcatlon illu~trated ln FIGVRE 32J
FIGURE 3~ 1- an xplod-d ~ld- vl-w o~ ~tlll another alternatlve embodl~ent o~ th- pr-~ent lnv-ntlon ~
FIGURE 3S 1- a ld- Vl-w o~ th- ~bodl~nt ~hown ln FICUR~ 34 lllu-tratlng th- barrl-r ln--rt-d ln th- h-lls FIGURE 36 l~ a plan vlew o~ an lnstrument used to lnsert and r-mov- the barrler ~rom the ehell o~ the hearlng aid FIGURE 37 18 a plan vlew o~ th- lnetrument shown ln FIGURE 36 rotated 90 degreest FIGURE 38 1B a plan vlew o~ the top end portlon o~ the instrument shown in FIGURE 37 ALLECR~ETTI ~ WITCOFF Lr~

C~ICAOO. ILLINOIS #00 TELEP~tONE (312) 7t~l00tt . .

2011 ~732 FIGURE 39 1~ a plan view of the botto~ end portlon of the instrument ~hown in FIGURE 37;
FIGURE 40 i8 a partial plan view of th- bottom end portion of the in~trument ~hown ln FIGURE 37;
S FIGURE 41 i- a partlal cro~ ctlonal vl-w of th-bottom nd portlon of the instrument hown in FIGURE 37, with the in~trument ngag-d with th- barri-rs and FIGURE 42 i~ a persp-ctlve vlew o~ a set of replacement barrlex~ and an lnsertlon and r-moval ln~trum-nt ln a contaln-r AL~EGFI~ETTI ~ WITCOFF L~
~0 ~OllTt~ WACKER O~IVE
CllICA~30. I~LI~1015 ~1#
TEI.EF~ONE /3-2) ~-51000 2~ ~73~

DBTAILED ~PSCRIPTI0~ oF ~L~R~F~RR~D ~M~QDIKEN~8 Re~erring to FIGURES 1-42, a pre~err~d embodiJent o~
th- pre~ent invQntion io shown as an improved barri~r, generally deolgnated 20, ~or an "ln the ear" or "canal" type hearing ald, illu~tratlvely designated 22 So-call-d "custom" or g-nerlc hearing aid~ are d-~lgned to ~it ither in the bowl o~ th- ar or, alt-rnatlvely, ln the e~r can~l it~el~ Prior to th- dev-lopment Or ~uch ald~, howev-r, h~arlng ald~ w-r- de-lgn~d to b- worn b-hlnd th- ~ar or l~-where A prlor art b-hlnd-th---ar h-arlng ald l- hown ln FIGURE 2 and d--lgnat-d 24 Th- h-arlng ald, or "ald, n 2 lnclud-d a pla-tlc ca-- 26 to hou-- th- h-arlng ald co~pon-nt-Typlcal ¢o~pon-nt~ lnclud-d a lcrophon- 28, ampllrylng clrcultrv ~not ~hown), r-c-lv-r 30, pla-tlo tublng 32, and ar nold 34 Th- ~lcrophon- would r-c-lv- a ~ound elgnal ~rom out~ld- th- ar and conv-rt lt to an l-ctrloal ~lgnal An l-ctrical ~lgnal waa th-n r-~ponalv-ly tran~lttod to the rec-lver 30 ao Th- r-c-lv-r 30 lnolud-d an aaou~tla output port 36 j lnt-rconn-ct-d to th- tublng 3a Upon r-colvlng ~lgnal~ ~rom th-l-ctrl¢al compon-nte wlthln th- aid 24, th- r-celv-r 30 would tran~lt ound lgnal- through lt~ exlt port 36 Thes- ound ~lgnal~ w-re then conducted, vla the tublng, to the ear ~old 34 and the interior ot the ear ot the u~er ~LLEGRE7TI F 'HITCOFF Lt~
~O SOliTI1 W~CKER DRIVE
Ct~ GO. ILLINOIS tO~
TELEPIIONE l~t2) tl~o~o 2~ ~732 In the prior art embodiment shown ln FIGURE 2, the acoustic exlt port 36 of the receiver 30 was physically lsolated from the ear environment by the tubing 32 As a result, the migration of the ~olld or semiliquid oar wax materlal into the receiver 30 wao negligible due to the physical lengt~ o~ th~
tubing With the decrea-ed lz- o~ electronic componento ln the 1970'- and l9ao~ how-v-r, mor- eo-m-tlaally attractiv- h-arlng ald~ oould ~- aonotruet-d Sueh ald- ~it ln th- ar or th- ar canal o~ th- uo-r 8e- tho ald 22, hown ln FIGURE 3 ~ lk- th- prlor art ald 24 hown ln FIGURE 2, th- ald 22 ~hown ln FIGURE9 3 and 3a al~o lnclud-~ a ~hell 40 whlch may al~o lnclud- a mlcrophone 42, ampli~lcatlon clrcultry ~not ~hown) and a r-c-lv-r 44 Th- ~h-ll 40 and r-c-lv-r 44 ach lnclud- an acou~tlc output port, r--p-ctlvely de~lgnated 46, 48 Th- output port- 46, 48 Or th- ~h-ll 40 and r-c-iver 44 ar- lnt-raonn-at-d by a h-arlng ald ound ahann-l 50 ~h-barrl-r 20 1- po-ltlon-d ln th- chann-l 50 b-tw--n th- two acou-tla output port- 46, 48 ~hu-, ound xi-t- ~roa output port 4~ o~ th- r-c-lv-r ~4, trav-l- through th- barrl-r 20, through th- ~ound ehann-l 50, and out th- output port 46 o~ the shell 40 Agaln, th- mlcrophone 42 receives ~ound signal- and rQsponsively transmlt~ an electrlcal signal An ~lectrlcal slgnal, ln turn, is sent to th~ r-celver 44, whlch convert~ lt to a ~ound signal The sound signal i~ then tran~mltted, through ~LLeGRETTI ~ wncoFF Lro 10 SOUTH W~CKER ORIVE
CllICAGO. ILLINOIS ~OF
TELEFl~ONE ~10 71~-10~0 - 2~8732 th- acou-tlc port 48 o~ th- receiv-r 44, through the ~ound channel 50 o~ tho aid 22, to the acou~tlc exlt port 46 in the shell 40 of the hearing aid 22 After leaving the ~hell 40 o~
the aid 22, the ~ound ~ay travel down the ear canal 52 o~ the user, to the ear drum Ae ~hown in FIGURES 3 and 3a, th- recelv-r exlt port 48 1~ ln clo~- proximlty to th- ar canal 52 contalnlng wax genorating tl-~u- A- a r--ult, wax ~r-qu-ntly ~lgrat-~ through th- xlt port 46 in th- h-ll 40, upwar~ through th- ound chann-l 50, and lnto th- ~xlt port 48 and th- r-o~lv-r 44 lt--l~
Thl- cau--- alogglng o~ th- r-c-lv-r 44 or h-ll port 46, r-du¢lng lt~ acou-tlc galn, pow-r output, and occa~lonally th-co~pl-t- ~allur- o~ th- ald 22 to a~pll~y or oth-rwi~- uodl~y ~ound In a pr-r-rr-d nbodl~-nt o~ th- pr-o-nt lnventlon, the barrl-r 20 i- lnt-rconn-ct-d b-tw -n th- r-c-lv-r ~4 and aaou~tlc xlt port 46 Or th- h-arlng ald h-ll 40, a~ hown ln FIGURES 3 and 3a For the pr-~-rr-d obodl~-nt ~hown, th- acou-tlc output port 48 o~ th- r-a-lv-r 44 1- approxlnat-ly cyllndrlaal Thu~, th- barrl-r 20 lt~ ub~tantlally cylln~rlaal, ~lttlng ~nugly ln th- ~h-ll output port 4C S-- FIGURES 3 and 3a AB
~hown ln FIGURES 3 and 3a (ror xampl-, ln FIGURE 13) th- barrler 20 ~ay b- plac-d ln a varl-ty o~ locatlon~ ~etween th- r-c-lvar 44 and acoustlc output port 46 In other embodlment3, o~ cour~e, the barrler 20 ~ay be comprlsed Or other cross ~ectlonal con~lguratlons Thus, ~or ~lUEGRETTI ~ WITCOFF. E-~
0 50UTN w~C)tEP DfllVE
Cl-ICAOO. I~IN019 ~03 TE~EPflONE ~3121 Tl~ 10~0 :

2~ 3~
example, the barrier 20 could be mad- a part o~ the hearing aid 24 That 1~, the barrler 20 may be a~eembled as a part of the shell 40 or a~ a part o~ the receivex 44 . The barrlor 20 furth-r acte a- a varlable acou~tic re~i~tance to acoustically dampon th- frequency responE~e Or the hearing aid rsceiver S-e the example Or acoustic damping shown, for lllu~trative purpo~-a only, in FIGURE 1 A~ shown in FIGURE 4, on- mbodim-nt of the barrior 20 lnclud-~ a hou-lng 54 and ~lr-t, ~-aond, thlrd and fourth pro~ectlon-, r-~pectlv-ly d--lgnat-d 56, ~8, 60, 62 Of cour--, a l----r or gr-at-r nu b-r of pro~-ction~ may b- u--d Th- hou~lng 5~ ln thl- ~bodlm-nt 1~ ~ubetantlally cyllndrlcal, d-~inlng a wall 64 wlth flr-t and -cond end- 66, 68 and may b- comprl~-d of a varl-ty of Jat-rlale In th- pr-f-rr-d lS ibodlment, ln~-ctlon mold-d th-rmopla-tlc le u~-d Example- of mat-rlal- that mlght b- u~-d to mak- th- hou-lng lnclud-"Cycolaa,~ and AB8 ~Acrylonltrll--Butadl-n--9tyr-n-) r--ln Th- dln-n-lon- o~ th- on- partlcular mbodlment Or th-lnv-ntlon h-r-ln d-~arlb-d ~ollow 0~ cour~-, alt-rnatlv-~bodlm-nt~ ar- po~lbl-, and th- dlm-n~lon~ ~hould not b- r-ad to llmlt tha ~aop- o~ th- pr-~-nt lnventlon The hou~lng 54 deflne~ a length, between the ~ir~t and second end~ 66, 68, of approxlmately 35 lnch, and the inside diameter of the housing 54 is approxlmately 11 lnch The thicknee~ of the housing wall i8 approximately 01 inch, and the hou~ing 54 further definos an intorior chamber 70 and an interior AL~EGRE7r~ ~ Wl-COFF L~n 10 Sa~TIl WACKEP DPIVE
CI~ O. I~LINOIS OOU1 TELEP110NE ~312) 71~

2~ 8732 sur~ace 72 In additlon~ the housing 54 derlne~ a central axl~
o~ pa~shge 74 b-tween the ~lrst and second end~
In the one preferred nbodlment h-r-ln d-~crlb-d, the central axl~ 74 pa-~e- through th- c-nt-r o~ a roughly cyllndrlcal hou~lng 54, ~ub~tantlally quldl~tant at all polnts ~rom th- interlor sur~ac- 72 o~ th- hou-lng S4 ~h- ~lr~t nd 66 ~lt~ ~nugly lnto the r-celver xlt port 48 Th- econd end 68, dl~tal ~rom th- r-a-lv-r 44 wh-n ln u-- ln a h-arlng ald 22, ~ac-~ the acou~tlc xlt port 4G o~ th- hearlng ald ~h-ll 40 and the int-rlor o~ th- u~-r'~ ar A~ hown, ach o~ th- ~our pro~-ctlon- 56-62 1-~ub~tantlally l~llar to th- oth-r- ~0~ cour~e, a slngl-barrl-r could al-o u~- a varl-ty o~ dl~f-rently hap-d pro~-otlon- ) Only th- ~lr-t pro~-ctlon S6 la dl-cu~--d ln detall b-low for lllustratlv- purpo~-~
Th- pro~-ctlon 56 le attach-d to th- lntorlor ~urrace 72 o~ tho hou-lng 54 and xt-nd- lnwardly toward th- c-ntral axls 74 o~ th- hou~lng S4 Th- pro~-ctlon S6 partlally occlud-e th-c-ntral acouetlcal pa~ag-way or lnt-rlor hou-lng chaub-r 70 ~n th- pr-~-rr-d ~bodl~-nt, th- pro~-ctlon 56 1~
aomprl~-d o~ a th-r~opla~tlc that can b- ln~-ctlon nolded, ~u~t a~ the hou~lng 54 1~ In an alternatlv- mbodl~ent, o~ courE~e, th- pro~-ctlon S6 could al~o b- cov-r-d wlth a coating that exhlbit~ a low coheE~lon to c-rumen Such coatlngs lnclude, ~or 2S xa~pla, "T-~lonn such coatlng would ~ak- any pro~-ctlon or hou~lng easier to clean after wax has bullt up upon it ALLEGRETTl ~ INlTcOFF L~o 10 80UTR W~CKER DRIVE
C~IC-~GO. ILLIN018 ~Ot TELEPHOIIE IJ12) 71~1000 - 2~ 8732 I~ the hou~lng 54 18 cylindrlcal, tho pro~ection 5C
de~ines an outslde perimetar 76, a portion o~ which resembles a clrcle Alternatively, the pro~ectlon 56 may be described a~ a disk While the lnventlon encompasees a variety of pro~ection ~hap-~, th- pr~-rred mbodim-nt Or F~GURE 4 lnclud-~ a dl~k havlng a wQdg--shaped gap 78 In thl- on- pr-f-rr-d embodim-nt, the pro~ect~on 56 de~lnes a maximum outside diameter of approximately ~l lnch, ~o that it A'lto tightly against th-interlor ~ur~ac- 72 oA' th- hou-lng ~4 In th- pr-~-rr-d ~bodlm-nt, th- pro~-atlon S6 1-attach-d to th- lnt-rlor urtaa- 72 ot th- hou-lng ~4 ~n th-pr-r-rr-d ~bodlm-nt, th- attaahmont 1- accompll~h-d wlth etrong glu- ~uch a~ a ayanoacrylat- ~t-r In alt-rnatlv- mbodim-nt~, how-v-r, th- pro~-ctlon 56 could b- mold-d a- part o~ th- houolng 54, or alternatlv-ly, lmply pr~ lt lnto th- lnt-rlor chamber 70 o~ th- hou~lng 54, or oth-rwl-- attach-d to th- hou~lng 54 Th- houolng 54 ln th- pr-~-rr-d mbodlment doA'lne- an lnterlor oro~ -ctlonal ar-a o~ a alrcl- and clrcl- lnt-rlor Agaln, a portlon o~ th- clral- lnt-rlor 1~ occlud-d by the pro~-atlon 56 Sn th- pr-~-rr-d ~bodlm-nt ~hown ln FSGURE 4, tho pro~atlon 56 1~ ln tho ~hap- o~ a dl~ wlth a wedge 78 removed The "removed" portlon 18 d-scrlbed as a "wedge" 78 for purpos-s o~ lllu~tratlon It 18 to be undorstood, o~ course, that whlle a wodge typlcally has only stralght sldes, the wedge 78 ds~lnlng an open area ln tho present context may al~o lnclude A E~RE~I~w,rc 10 SOUT~ WAC~EPOPIVE
CINCA~O. I~INOIS 0~
TEEFP~IONE 10121 715.10~0 2~1~73~
one roundod slde missing from the rounded pro~ection 56, shown ln using alt~rnative terminology, tho pro~ectlon 56 may be de~cribed as a "270 circle portion " ~he central axis 74 O~r the hGusing 54 defines the center polnt o~ the clrcle Al~o, tho "gap" from the pro~ectlon 56, may be descrlbed a~ a so circle portlon Th- op-n wedg- 78 of th- pro~-atlon 56 d-flne- an op-n ar-a ln th- aro~ -ctlonal ar-a ot th- hou-lng 54 Thu-, lf one w-re looklng through the hou-lng from th- flr-t nd 66 toward the ~-cond nd 68, parall-l to th- axl- 74, th- lnt-rlor of th-hou-ing 54 would d-fln- à alrcle lnterlor The pro~ectlon 5C
would block th- lnt-rlor 76 of th- hou-lng 54 xcept for the wedg- 78 Th- flr-t pro~-ctlon 56 lt--lf d-fln-- a ~ir-t ocalud-d ar-a and th- w-dg- 78 d-fln-- a flr-t op-n ar-a ln the cro~ ctlonal ar-a of th- hou-lng 54, nornal to th- axl- 74 It 1~ through thl~ open area, or w-dg- 78, ln the hou~lng 54 that ound may trav-l fro~ th- r-celv-r 44 to th-exterlor of th- ald 22 I~ thl~ ~ro~-atlon S6 war- the only barrl-r, how-v-r, wax, und-r ~om- clrcumatanc-~, ulght flow through th- op-n ar-a Thu-, at l-a-t th- on- addltlonal, ~-cond pro~-ctlon S8 l- u~ually provlded to pr-v-nt further pa~eage of ear wax In the preferred embodiment, the second pro~ectlon 58 i8 placed approxlmately 02 lnch away from the flrst pro~ectlon 56 Appllcant has found that, in the most preferred embodiments, ~LLEGFtETTI ~ WITCOFF LrD
~O SOLlTtl WACI~ER OPIVE
C~ICA~O. ILLINOIS ~
TELEPIIONE 13~2) 7~000 2~18732 th- pro~-ction~ ~hould b- placed apart nough o that the pro~octlon~ wlll not oubotantlally e~fect the overall acoustic response and the amount of expected wax bulldup wlll be leso than the diotance between the pro~ectlons Thuo, opaclng between the pro~ectlons of 005 inch to 04 lnch may be used ~or the mo~t pre~erred performance o~ the barrler 20 In the pre~erred embodlmont ohown, the pro~ectlon~ 56-62 aro lnterdlgltated wlthln th- hou-lng 54, llgh~ th-pro~octlon- ar- p-ai411y and angulàrly dl~plac~d wlth r-~p-at to th- aentral axl~ 74 Th- p~o~-atlon~ could b- mad- o~ ~ varl-ty o~ ~ub-tanc~ uch a-, ~or xampl-, th- th-rmopla-tla or ~emlp-rm-abl- mat-rlal 0~ cour--, th- pro~-ctlon- may b-radlally or axlally dl-placed rrom ach other The econd pro~-ctlon 58 1- llk- th- ~lr-t pro~-ctlon 56 ln that lt de~ln-o a e-cond w-dg- 80 Whll- th- -cond wedg-o~ th- pr-~-rr-d mbodlm-nt ha- th- am- hap- a- th- ~lr-t w-dg-78, th- -cond w-dg- 80 may, o~ cour~- dl~-r ln lz- and ~hape o~ any other wedg- Th- o-cond pro~-ctlon 58 and econd w-dge 80 al-o d-~ln- an ocalud-d ar-a and an op-n ar-a ln th- hou-lng, norm~l to th- axl- 7~ Th- op-n ar-a o~ th- -aond pro~-atlon 58 1~ po~itlon-d ov-r th- ~ir-t occluded area Thu~, a tortuou~
path i~ provlded ~or wax whlch would otherwl~- mlgrate ~rom the ~lr~t end 66 to the ~econd end 68 For th- pr-~-rred mbodlment ohown ln FIGURE 4, the wedgeo 78, 80 meaoure approxlmately 90 Th- ~econd pro~ectlon 58 is oimilar to the ~irst pro~ectlon 56 ln deslgn, but has been ~LLEGRETTI a wlTCOFF LID
10 SOUTN W~CKER ORIVE
C~IC~GO~ ILLIIIOIS 00)3 rELED~ONE 13~2~ 715 ~OI10 2~1873~

rotated clockwl~o 90 ~rom the po~ition o~ the rir~t pro~ection 5C Finally, the ~ourth pro~ectlon 62 ha~ been rotated so ln a clockwise direction from the position of the third pro~ection 60 In the pre~erred e~bodiment ~hown in F~GURE 4, the open area o~ each Fro~ection i- ~urth~r bloc~ed, or occlud-d, by occluding portions o~ three oth-r pro~-ctlon~ The int-rdigitated pro~ection~ thu~ cooperat- to co~pl-tely occlude tho acou~tlcal pa~ag-w~y 70 agaln~t wax mlgratlon That 1~, ~vcry llne o~ mlgratlon through th- hou~lng 54 along th- lnterlor ~ur~aaè 72 1~ lnt-rruptod by a pro~-ctlon Applicant- hav- ~ound that ~uch a con-tructlon provld-- a tortuou- path rOr ar wax, ~ubetantlally r-duclng th- amount ot ar wax that ~ay ~lgrat-~ro~ th- ~ound chann-l 50 to th- r-c-lv-r 44 whll-, at th- am-tlm-, provldlng ub-tantlally llttl- acou-tlc imp-danc- to th-re¢elver 44 A ~-cond mbodl~-nt o~ th- pr-~-rr-d lnv-ntlon l-di~aloc-d ln FlauRE S Th- barrl-r 82 lnolud-a a hou~lng ~4 and a multlpllcity o~ pro~-otlon- Th- barrl-r ~2 lnclude~ ~lrst, -oond, thlrd, and ~ourth pro~-atlon~ 86, 88, 90, 92 Conotruotion o~ th- houclng 8~ lc cl~llar to that ahown ln F~auRE
4 Alao, th- pro~-otlona 86-g2 ar- o~ ~ub~tantlally the ~a~-thlckn-~ and po~ltlon-d ub~tantlally th- ~am- dl~tanc- apart a~
the embodlment ~hown ln FIGURE 4 Howev-r, rather than being 270 clrcle portions, each pro~ectlon iB ~ub~tantlally a 180 clrcle portion (or semiclrcle) A~LEGFETTI L VIITCOFF L-~

ClIICAl30~ ILLINOIS 8030t TELEPHONE ~312) 71~ -000 2018~32 Th- ~ir~t pro~ctlon 86 agaln d-~ln-- a ~lr~t occludQd area and a ~lr~t open area The second pro~ction 88 hae been eftPectivoly rotated such that the occluded area o~ the second pro~ection blocks the open area of the first pro~ectlon 86 The S thlrd pro~ectlon 9o block~ the open area o~ the eecond pro~ection 88 slmllarly, the rourth pro~ectlon 92 block~ the open area of the thlrd pro~ection 90 As ohown in FIGURE 6, euch an arrang-~ent o~ 180 elrcl- portlon pro~-otlon- 86-92 pr-v-nt- wax ~ron rlowlng dlr-ctly through th- hou-lng 84 A ub~tJntlal bulldup o~ wax 9~
aay b- antlolpat-d on th- ~lr~t pro~-ctlon ov-r th- llr- o~ th-h-arlng ald 22 Th- -cond pro~-otlon ~8 ~ay b- xp-ct-d to reo-lv- a l----r amount Or wax bulldup 96, lne- lt 1~ poeltlon-d ~llghtly deep-r lnto th- hou-lng 84 Th- thlrd pro~ectlon 90, how v-r, xp-rl-nc-- ub-tantlally ~all-r anounte Or wax bulldup 9~, elnc- th- path ~or wax ~lgratlon ha- b--n block-d by th-~lr~t and -cond pro~-etlon- 86, 88 Th- rourth pro~-ctlon 92 r-o-lv-e v-n 1-~- wax bulldup, b-eaue- o~ th- wax alr-ady bloak-d by th- ~lret thr-- pro~-etlon- 86-90 Y-t anoth-r ibodl~-nt o~ th- pr-e-nt ln~-ntlon 1-ehown ln FIGURE 7 ~h- barrl-r 100 agaln lnalud-e a houelng lOZ
and a aultlplloity o~ pro~-etlone 104, 106, 108, 110 The houelng 1~ ~ubetantlally slmllar to that ~hown ln FIGURES 4-6 Each o~ the ~our pro~eotlone 104-110 le comprleed o~ a serie~ of 24 spoke~ 112, 114, 116, 118, radlatlng fro~ centr~l polnts 120, 122, 124, 126 de~lned by the central axis 128 Each ~-LEGFIETTI ~ wlTCOFF L-~
10 SOUTH W~CI~ER OPIVE

CHIC~O. I~UNOlS tClW
rELEPHONE ~1217-5 -000 - 2~18732 po~ approxlmat-ly 01 lnch ln dlam-t-r In th- pr-~-rr-d embodlment, of cour~e, the pro~ectlon~ 104-110 are agaln made of pla~tlc, and the ~econd pro~ectlon 106 1B e~fectlvely rotated a few dogr~s ~ro~ th- po~ltlon o~ th- ~lr~t pro~octlon 104 In turn, the thlrd pro~-ctlon 108 ka- b--n rotated llghtly ~ron th-po~ltlon o~ the ~econd pro~ectlon 106, and the ~ourth pro~-ction 110 ha~ a po~ltlon rotat-d llghtly ~rom th- po-ltlon o~ th-thlrd pro~octlon 108 Y-t anoth-r alt-rnatlv- ~bodl--nt 1- hown ln FIauRE
8 In thi- mbodl~-nt, th- barrl-r 130 lnalud-- a hou-lng 132 and rlr-t, econd, thlrd, ~ourth, and ~l~th pro~-ctlon-, 134, 136, 130, 140, 142 Each o~ th- pro~-ctlon- 134-1~2 conprl--~approxl~at-ly a portlon o~ a clrcl- portlon Th- -cond pro~-ctlon 136 ha- b--n rotat-d ~rou that o~ th- ~lr-t pro~-ctlon lS 134 Th- thlrd, ~ourth and ~l~th pro~-ctlon- 133-142 ar-sl~llarly rotat-d ~ro~ th- po-ltlon o~ ach oth-r pr-vlou-pro~-atlone Wh-n th- hou-lng le vl-w-d rrou th- dlr-ctlon o~
th- arrow o~ th- axle 144 hown ln FICURE 9, th- ntlr- lnt-rnal croe--e-ctlonal ar-a o~ th- hou-lng 1- agaln bloe~-d by th-pro~-ctlona 134-1~2 Th- plurality o~ pro~-otlon~ 134-142 hav- approxl~at-ly th- an- thlokn-~a and dl-pla¢-m-nt along the axl~ 144 a~ the pro~-ctlon- pr-vlou~ly d-~crlb-d ~or th- ~bodl~-nt~ shown ln FIGURES 4-7 Th-r- ar- ~lv-, rath-r than ~our, pro~ectlon~
however Thu~, the hou~lng 132 1~ approxlmat-ly 02 lnch longer than the hou~ing S4 ~hown in FIGURE 4 ALLEGFIFTTI ~ WITCOFF. Llo 0 SOUTtl WACKeR OFIIVE
CI~ICAGO, ILLINOIS ~OL
TELEF~ONE 1~2) 7~5 ~000 2~1 873~

Yet another alternatlve embodlment 1~ shown ln FIGURE
9 Llke the embodlment shown ln FIGU~E 5, the barrler 146 1,7 FIGURE 9 lnclude8 a hou~lng 148 and a plurallty o~ pro~ection~
150, 152, 154, 156, and each o~ the pro~ectlon~ 150-156 are 5 approximAtely 180 circle portion~ However, each pro~ectlon 1A
rotated approxlmately 9o (rath-r than 180) rrOm the pr~cedlng pro~ectlon Thuo, th- ~econd pro~ectlon 152 ha~ b--n rotated approxlmately 90 ~rom th- po-ltlon o~ th- ~lrst pro~-ctlon 150 Th- thlrd and fourth pro~-ctlon~ 154, 156 ar- al-o rotAt-d approxlmat-ly 90 A furth-r pr-~-rr-d ~bodlm-nt 1- hown ln FICURE 10 Each of th- pro~-ctlon- 160-166 comprl--- approxluat-ly a 90 clral- portlon Th- -cond pro~-ctlon 162 ha~ b--n rotat-d approxlmat-ly 90 ~rom th- po~tlon o~ th- flr-t pro~ectlon 160.
slullarly, the thlrd pro~-ctlon 164 1- rotat-d approxlmately 9o ~rom the po~ltlon Or th- -cond pro~ectlon 162 The ~ourth pro~-ctlon 166 ha- a po-ltlon whlch 1- rotat-d approxlmntely 90 ~ro~ th- po~itlon of th- thlrd pro~-ctlon 164 A alxth pref-rr-d ~bodlm-nt o~ th- pr-~ent lnv-ntlon la ~hown ln FIGURE~ 15 aa a barrl-r 200 for a h-arlng ald 202 A- b-at ~hown ln FICURE 13, th- h-arlng ald 202 lnclud-~ a h-ll 204 àdapted to b- ln~-rted ln an ar channel (not ~hown) and deflnlng an acou~tlcal outl-t port 206 The hearlng ald 202 further lnclude~ a rec-iv-r 208 h~vlng a recalver outlet port A~E~3F;ETTI ~ WITCOFF LID
0 SOUTI1 WACKEFI DmVE
C~IICAGO. I~INOI3 00~
TELFD~ E IJ~I 7~ 000 2~873:~

In thl~ preferred embodiment, the recolver 203 i~
~ecured withln the shell 204 by an la~tomerlc ~llllng 212 That i~, the receiver 208 1~ po~ltionally set wlth re~pect to the ~hell 204 and then embedded ln the ~llling 212 Once the fllllng 5 212 cure~, the r-celv-r 208 1- e-cured a- well a- protect-d by the pllable, ~hock-ab~orblng ~ill-r 212 Th- ~h-ll 204 lnclud-- an lnt-rnally threaded op-nlng 214 whlch lnterconnect~ th- acou-tlcal outl-t port 206 wlth th-lnterlor chamber 21C o~ th- h-ll 204 Thl~ op-nlng 214 1-adapted to rec-lv- th- barrl-r 200 A- b--t hown ln FICURE 13, th- ~hell 204 1- ~lll-d ln euch a mann-r that th- la-tom-rlc ~ r 212 d-~lne- a ub-tantlally cylindrlcal chann-l 218 l~m-dlat-ly ad~ac-nt th- r-c-lv-r outl-t port 210 and an lnt-rnally-threadod cavlty 220 lmm-dlat-ly ad~ac-nt and extendlng th- op-nlng 214 lnto th- lnt-rlor cha~b-r 216 On- advantag-ous ~-atur- o~ th- ~lll-r 212 1~ to -al th- op-nlng 220 ~rom the cha~b-r 216 to avold acou-tla t--dback to th- mlcrophon- 42 In thl~ pr-~-rr-d mbodlm-nt, th- barrl-r 200 1~ an lntogral plec- o~ mold-d th-rmopla~tlc mat-rlal, ~uch a~ A~8 Th- barrl-r 200 lnclud-- a ub~tàntially cyllndrlcal houslng 222 de~lnlng a c-ntral acou~tlcal pa~ag-way 224 between a barrler lnlet port 226 and a barrl-r outl-t port 228 The housing 222 ha~ an xternally-threaded portlon 230 and a collar portion 232, whlch de~lnes the outlot port 228 A~ shown, the outer dlameter o~ tho collar portlon 232 1~ ~llqhtly greater than th- outer diameter of the externally-threaded portlon 230 ALLEGRETTI ~ WITCOFF LtD

C~`IIC,~ LINOIS 00~0~
TELEP~ONE 1312) rl~.lo00 2nls732 The hou~lng 222 1~ adaptad to be r-celved by the lnt-rnally-threaded oponlng 214 o~ th- ~hell 204, a~ ext-nded by the ~lll-r 212. S-cured thereln, the central axls 234 o~ the hou~ing 222, or more partlcularly the central acou~tlcal 5 pa~8ageway 224, substantlally allgn~ wlth the receiver outlet port 210. The barrier lnlet port 226 allgne wlth and ~llghtly ov-rlay~ th- chann-l 218, ~uch that audlo slgnal- produced by the r-c-lv-r 20~ ar- r-c-lv-d by th- barrler 200 and pa-- through the aoouatlcal pa~ag-way 224 That 1~, th- pa-~ag-way aaou~tlaally llnke to r-aelv-r 208 to th- outl~t ~06 o~ th- h-arlng ald 202 In thl- pr-r-rr-d ~bodl~-nt, th- collar portlon 232 o~
th- hou-lng 222 lnclud-- dla~-trlcally oppo--d lot~ 236A, 236B, xt-ndlng ~ro~ th- ~ub~tantlally cyllndrl¢al barrier outl-t port 228. ~h--- lot~ 236A, 236~ coop-rat- to d-~lne key ~-an~, genorally d-elgnated 238, ~or rotatlng th- barrl-r 200 wlth an ln~tru~-nt havlng a cr-wdriv-r-llk- con~lguratlon (not hown) Utlllzlng th- ~-y ~-an- 23~, th- barrl-r 200 can b- r-adlly r-~ov-d ~ro~ th- h-ll 204 ~or cl-anlng or r-plac-~-nt Th- barrl-r 200 or ~or- partlcularly th- xt-rnally-20 thr-ad-d portlon 230 o~ th- hou-lng ~2 lnalud-~ an aao-0~
op-nlng a40. A~ b-~t ~hown ln FIGURES ll and la, the acce~s openlng ~0 18 ~ub~tantlally r-ctangular and ~ubstantlally centrally locat~d ln th- ext-rnally-thr-aded portlon 230. The acces~ op-nlng 240 provld-~ direct acce~s to th- pa~sageway 224 for ln~pectlon and cleanlng ~LLeGRETTI ~ WITCOFF. ErD
10 SOUTN W~CKEP. OF0VE
CI~ICAGO. I~IN019 ~0~
TE~EPIIONE ~:~12) ~1~1000 ..

- 2~18732 Re~errlng now to FIGURES 12 and 14, the barrier 200 al~o lnclude~ at lea~t two ~ub~tantlally ~e~l-clrcular pro~ection~ 242A, 242B, whlch extend lnto the pas~ageway 224 The pro~ectlons 242A, 242B are equally ~paced ~ro~ each other and ~rom the barrier inlet port 226 and outlet port 228 and ar~
~ub~tantlally p~rpendlcular to th- c-ntral axl- 234 and th-lnt-rlor wall ~ur~ac- o~ th- hou-lng 222 In thl- pre~-rr-d e~bodlment, th- pro~ectlon~ 242A, 2428 xt-nd ~llghtly b-yond th-~ldllne "HL" o~ th- aollar portlon 232 ~a~ ~hown b-~t ln FIaURE
14), sù¢h that th- pro~-ctlon~ 242A, 242~ llghtly ov-rlap Th- pro~-ctlon~ 242A, 242B ~h-r- and ln th- oth-r pro~erred mbodlm-nt-) lnt-rrupt th- c-ntral acou~tlcal pa~ag-way 224 ~uch that th- ~lgratlon o~ ar wax 1- r-tarded Tho pro~e¢tlons 242A, 242B cooperat- to de~lne trap ~ean~, lS gen-rally d--lgnat-d 244, ~or accu~ulatlng ar wax ln pred-t-r~lned accu~ulatlon lt-~ 246A, 246B, th-r-by r-tardlng ~low through th- c-ntral acou-tloal pa~ag- 224 wlthout ~ubstantlal lnter~-r-nc- wlth tho p-r~ornance characterlstlc- o~
the hearlng ald 202 Aa b-~t ~hown ln F~aU~E 14, th-aaau~ulatlon ~lt-~ ~46A, ~46B, ln aoop-ratlo~, xt-n~ compl-t-ly about th- lntorlor wall ~ur~ac- o~ the houslng 222 Th- barrl-r 200 1~ mold-d ln a ~lv--part mold 24~ ~hown ln FIGURE 15 Th- mold 248 lncludes uold halves 250A, 250B
adapted to receive ~lrst, s-cond and thlrd lnserts 252A, 252B, 252C As ~hown, th- thr-- lns-rts 252A, 252B, 252C coop-rat- to ALLeGFIE~l A WITCOFF, L-~
0 SOIIT~1 WACI~EF~ DPIVE
Cl~ICAGO. ILLINOIS ~
~ELEPI'tONE 13~ OOO

2~8~32 de~lne the central acou~tlcal pas~ageway 224 and acce~s openlng Re~errlng now to FIGURES 16 and 17, a modlf ied con~iguratlon for the pro~ections 242A, 242B is shown (Only one s pro~ection 242A i~ di-cu~sed herein ~or simpllclty ) The pro~ectlon 242A includ-- a di~k portlon 254 and a rlange portlon 256 The dl~ portlon 254 i8 ld-ntlcal to th- pro~ection 242A
d-~crib-d abov- and hoT~n ln FIGuRE5 12-ls Th- di~k portion 254 d-~lnea a t-r~lnu~ dg- 25a Th~ ng- portlon ~S5 ~xt-nd- ~ro~ th- t-roinu~ ~g-25~, ~ub~tantlally p-rp-ndlcular to th- dl-X portlon 254 Th-~lang- portlon 256 xt-nd- away ~rom th- r-c-iv-r 208 and toward~
th- acou-tical outl-t port 206 ot th- h-ll 204 Th- ~lang-portion 256 cr-ate- ~urth-r l~p-danc- to th- mlgratlon Or wax lS through th- barrl-r 200 and coop-rat-- wlth th- dl-k portion 254 to de~lne th- trap m-an~ 244 Th- dl-k portlon 254 lnclud-~ a ~-rl-- Or d-pr-~-ion~
or "dlmple-~, g-n-raAlly d-~lgnat-d 260, whlch ~urth-r retard wax mlgratlon by provldlng additlonal aa¢u~ulatlon ~lt-~ In ~-nc~, migratlon 1- r-tard-d ~lnc- th- d-pr-~aione 260 mu-t b-at leaat partlally ~ d b-~or- ~urth-r advanc-m-nt occur~
The pro~-ctlon 242A hown ln FIGURE 16 o~ers an addltlonal advantage Th- con~lguration o~ th- dl-k portlon 254 and ~lange portlon 256 provlde~ an ad~u~table acou~tlc damplng means and may, with proper dimen~ioning, provide ~ub~tantially optlmum damplng o~ the overall ~reguency response, ln comblnatlon ALLE~lRETTI a WITCOFF L-l~
10 SOIJT11 W~CKER DRIVE
Cl-IC~(30. ILLINOIS ~W
TEIEPUONE (312) 715-1000 -- 2~8~32 wlth the barrl-r 200 In one embodiment, the ~lange portlon 256 l~ conn-ctQd to th~ dl~k portion 254 by a ~llvlng hlnge~ The orlentatlon o~ the ~lange portlon 256 l~ ad~usted to provlde a varlably con~trlct~d acou~tlc pathway, thu~ provldlng the de~lred acouetlc damplng ln comblnation with th- barrier 200 Once properly po-itlon-d, the ~lang- portion 2S6 l- -cur-d to th-lnt-rior wall ~ur~ac- ot th- hou-ing 222 by glulng or oth-r mean~
A varl-ty o~ ~-thod- ~ay b- utlllz-d to -aur- aeou-tlc att-nuatlon- o~ th- h-arlng ald r-a-~v-r For xa~pl-, a lupl-plug ~ay b- ln--rt-d ov-r th- output port o~ th- h-arlng al~
Al~o, a a-nt-r-d plug may b- po-ltlon-d ln th- ound pathway, to provld- r--l-tan¢- to ~ound pr---ur- Whil- uch maan- do add acou~tlo r--l~tanc- to th- r-c-lv-r output, modl~lcatlon o~ th-lS acou-tlc r--l-tanc- 1~ dl~loult or lnpo--lbl- a~t-r th- plug ha~
been plac-d ln th- h-arlng ald durlng lt- manu~aeture Th-pr-~-nt lnv-ntlon provld-- n ad~u~t-bl- acou-tla lmy-danc- by n-an~ o~ an ad~u~tabl- ba~
A~ ~hown ln FIGURES 18 and 19, th- barrl-r 200 ~ay lnclud- an ad~u~tabl- acou~tlcal ba~ 6~ Th- ad~u~tabl-ba~ 262, or ~va~labl- acou~tlc att-nuator," lnclude~ a c-ntral, aub~tantlally cyllndrlcal ~-ctlon 264 and a palr o~ wlng ~-otlon~ 266A, 266B, whlch xtend ln oppo~ed r-latlon~hlp ~rom the central seetlon 264 Each o~ th- wlng ~ectlon~ 266A, 2668 1 substantlally r-ctangular and thln Th- ad~u~table ba~l- 262 1~
mounted on opposed pln~ 268A, 268B whlch extend fro~ the lnterlor ~LLEGRETTI ~ WITCOFF E-D
50 SOUT~ WACKER DRIVE
CI~IC~OO. I~LINOIS
TELEP110NE 13~2~ rl~

2~ 8732 wall ~urfac- o~ the hou~lng 222 and engag- the channel 270 de~lned by tho central ~ectlon 264 Th- orl-ntatlon o~ the ad"u~tabl- ba~ 262 may b- s-t by glulng or by ~ated, lnterlocXlng tab~ 272 on the lnterlor wall ~ur~ace o~' the houolng 222, equally ~paced about the plns 268A, 268B, and ~lots 274 equally ~paced about th- end~ o~ the central sectlon 264 o~ the ad~,u~table ba~'~'le 262 The ad~u~tabl- bar~l- 262 lnclude- an ad1,u~tment ap-rtur- 276, a-ntrally locat-d Jlong on- rld- o~ on- o~ th- wlng ~-otlon- 266A, 266B Th- op-n r--~ 278A, 278B b-tw--n th-ad~u-tabl- bat'~l- 262 ~nd th- proJ,-otlon- 242A, 242P provld- a varlably conetrlct-d pa~Eag-way ~or damplng o~ th- ov-rall acou~tla r-~pon-- Th- pa~-ag-way- 278A and 278B ar-~ub~tantlally rectangular ln hap- Each pa-~ag-way 278A and 278B 1~ de~'lned by th- dg-e 261A and 261B ot th- wlng- 266A and 266B, th- ad1acent ~ur~ac- o~' th- ~lang-- 242A and 242B, and th-lnt-rlor wall ur~aa- o~ th- hou-lng 222, r-~p-ctlv-ly Th-ub-tantlally r-ctangular pa-~ag-way- 27~A and 278B hav- varylng wldth~ d-p-ndlng on th- angular po-ltlon~ Or th- wlng ~-ctlon~
~66~ and ~6B Or th- adJuatJbl- ba~ 6~
In ach o~ th- ~bodl~-nt~ d-~crlb-d lmm-dlately above, a tortuou- path 1~ provlded to er~'-ctlvely reduce wax mlgratlon Mor-ov-r, ln ~om- ln~tanc-~, the mbodlment also lnclud-~ a ~ean~
~or ad"u~tlng th- ovtrall acoustlc damplng ln comblnatlon wlth the barrler 200 Non-theless, substantlal op-n ar-a~ are provlded to reduce acou~tlc lmpedance by the barrler In each o~

~LLEGF~ETTT ~ WITCOFF L-o 0 90UT~ WAC~EFT ~F~IVE
CI lC~ LIN019 tO~Q~
TELET'~TE ~312) 71S 10~0 -- 2~18732 the pr-~-rred ombodlment~, th- cro~s--~ctlonal area o~ the houslng 1- ~ub~tantlally blocked of~ by one or ~or- pro~ectlons In the proferrQd embodlment~ prevlou~ly d-~crlb-d, the barrler 20 1~ placed in th- sound channel 50 or otherw~e po~ltloned betwe~n the output port 46 o~ th- h-arlng ald shell 40 and the output port 48 o~ th- rec-lv-r 44 Such posltlonlng allow~ th- barrl-r 20 to block wax ~ro~ nt-rlng th- r-c-lv-r 44 rrOn th- out~ld~ o~ the hearlng ald 22 Ot course, lt 1~
und-r~tood that, a- an alt-rnatlva ~hodl~-nt, th- barrl-r 20 m~y b- lnt-raonn-at~d dlr-atly to or lnto th- output port ~ o~ th-r-c-lv-r 4~
R-~-rrlng now to FIGURE9 20, 21, and 22, anoth~r ~odl~i-d con~lguratlon ror tho pro~-ctlon- 242A and 242B 1-hown ~h- barrl-r 200 lnclud-- a rlb 300 xt-ndlng p-rp-ndlcular rrO~ th- dl-k portlon 254 n-ar th- t-r~lnu- dg-2S~ Or th- pro~-ctlon 242A to pro~-ctlon 242B, a~ ohown ln FIGURE9 20 and 20a An dg- 306 provld-- addltlonal ar-a ~or wax aaourulatlon FI¢URE 21 ahowa a con~lguratlon havlng plural rlb~ 302, 303, and 304 xt-ndlng b-t~--n th- dl-X portlon 2~ n-ar th-t-r~lnu~ dg- 2~ o~ pro~-otion ~4~A and pro~-ctlon 2428 Ih-rlb portlon 300 ln FIGURE8 20 and 20a, and th- rlb portlon~ 302, 303, and 304 ln FICURE 21, cr-at- ~urth-r l-p-danc- to th-~lgratlon o~ wax through the barrler 200 by provldlng addltlonal accumulation ~ite~

A~eGReTTI ~ WITCDFF. L-D
0 SO~JTII WACKER DRIve Cl ICAGO, IUIN019 ~
Te~F~ONe ~ 71~-1000 20~8732 Re~erring now to FIGURES 2S, 26, and 27, a ~tlll ~urther ~odlrlQd con~lguratlon ~or the pro~ection~ 242A and 242B
1~ ~hown Th- pro~ectlon~ 242A and 242B lnclude ext-n~lon~ 308 and 310, and teeth 312 and 314, re~pectively Th~ extension- 308 and 310 extend perp~ndicular to central axl- 234 and provid- an addltlonal barrl-r to wax entering barrier 200 Th- te-th 312 xtend ~ro~ dl~k portlon 254, parall-l to th- c-ntral axl- 234 and p-rp-ndlcular to the dl-k portlon 2S4, nldway b-tw--n th- pro~-otlon- 242A and 242B Th-t--th 31~ xt-nd ~ro~ th- dl-~ portlon 31~, parall-l to th-a-ntral axi- 234 and p-rp-ndloular to th- dl-k portlon 318, ~ldway b-tw--n th- pro~-ctlon- 242A and 242~ Th- t--th 314 ar-ad~ac-nt to tho dg- portlon 31C o~ th- pro~-ctlon 242B and ar-lnt-rd~gltat-d wlth th- t--th 312 a- hown ln FIaUR~ 27 Th-lnt-rdlgltat-d rlb portlone 312 and 314 cr-at- ~urth-r lmp-danc-to th- ~lgratlon o~ wax through th- barrl-r ~00 by provldlng ~tlll ~urth-r accu~ulatlon elt-~
Th- rlbo 300, 302, 303, 304, and rlb t--th 312 and 314 alao provld- an ad~uotabl- aaou-tla da~plng ~-an- and ray, wlth prop-r dlmen-lonlng and poaltlonlng, provld- ~ub-tantlally optl~u~ da~plng o~ th- ov-rall ~r-qu-ncy r-epon~-, ln combinatlon wlth th- r-~t o~ th- barrler 200 onc- prop-rly dl~en~ioned and po-ltion-d, th- rlb- 300, 302, 303, 304, and lntordlgitated teeth 312 and 314 may b- ~e¢ur-d to the pro~ectlon~ 242A and 242B by gluing or other adhe~lve ~-an~ or, pr-~orably, ~ay b- ~olded as a ALLEGRTTl ~ WITCOFF L-D
~I,ITH W~ICKER ORIVE
CHlcAGo~ ILLINOIS LO~O~
TELEDHONE ~1-2) 715--COO

, , .

, 2~18732 part o~ th- pro~ection- 242A and 242B during th- ~anu~acturlng process .
Rererring now to FIGURES 22, 23, and 24, an additional barrler ln th~ ror~ o~ a ~cre-n coupl~d to barrler 200 le shoTdn FIGURE 22 llluetrates a ecrQen 320 coupled wlth th- prevlously deocrlbed portlon o~ th- barrler 200 The screen 320 further lmped-s the ~low Or wax that 1- not ~ully ~topped by the rest o~
the barrler 200 A~ dl~aw ~-d pr-vlou-ly, th- cr--n 320 1~ po~ltlon-d ln~ld- th- h-ll ~04 b-tw -n th- rlll~r 212 and barrl-r ~00 to provld- a barrl-r b-tw--n barrl-r 200 and cyllndrlcal ahann-l 213 Th- ¢r--n 320 ~ay b- coupl-d to th- barrl-r 200 by glu- or oth-r adh-~lv- ~ean~ Alt-rnatlv-ly, th- cr--n 320 ~ay b- h-ld lnto po~ltlon ~lnply by ~rlctlon a~t-r lt 1~ -nugly rlt lnto the barrler 200 Th- ~cr--n 320 al-o provld-- an ad~u-tabl- acou-tlc damplng ~-an- and ~ay, wlth prop-r cr--n ~--h d-n~lty, provlde ~ub-tantlally optluu~ acou-tlc da~plng o~ th- ov-rall ~r-qu-ncy r-~pon~- ln co~blnatlon Twlth th- r--t o~ th- barrl-r 200 Th-~r-qu-nay r-epon~- ~ay b- tallor-d to aaaurat-ly natab th-r-gulr-~-nt~ o~ th- h-arlng lmpalrad u--r by ~lmply and qulckly replaclng the creen 320 wlth another screen o~ a dlr~erent screen m-~h d-n~lty The ~creen 320 includes a rl~ 322 and a screen mesh 324 Typlcal speclrlcations ~or the ~creen 320 ~ay include a etalnless ~teel wlre screen wlth a ~e~h count o~ approxlmately ALLECRETTI ~ WITCOFF. Llll ~0 SOLml W~CKEa OFIVE
CllICAOO. ILLINOIS ~#
TELEPIIONE 1~121 rl~ ~000 2~18732 lCS, a nomlnal wire dla~eter of 0 002 inch, a m-~h openlng o~
0 0041 ineh, and a 45% opQn area Alternatlvely, the ~creen 320 may includ- a wlre ~cr--n wlth a me~h count o~ approximat-ly 200, a nomlnal wire dlameter o~ 0 0021 inch, a mesh op-nlng of o 0029 S lnch, and a 34% open area Values o~ ~esh count, wlre dlameter, m-~h op-ning ~iz- and op-n ar-a ar- typically ~-tw--n the valu~-~peclfled above for proper acou~tlc damplng and e~-ctlve wax ~low ~topp~g-A~ ohown ln FSGURE8 22, ~3, 24, and 28-31, th- cr--n 320 provld-~ a eeond lln- of d-~-n~- aqaln-t ar wax ~lgratlon Th- ~or--n aot~ a- a furth-r wax oatch-r ~or wax partlal-- that này pa-- through th- barrl-r A larg~ h cr--n prot-ct- th-ree-lver and lnt-rlor of th- hearlng ald from ~a~or wax partlel-~ A flne er--n, of eour~ rovld-- prot-etlon agalnst ~mall-r partlcl-~
In an alt-rnatlv- ~bodl~-nt of th- pr---nt lnv-ntlon, a acr-~n 320b ~ay b- po~ltloned ln -rl-~ wlth an addltlonal ~or--n 320e a~ ~hown ln FSCURE 28 Th- ~cr--n d-nslty, re~l~tance to wax flow, and aeou~tle ln~-dane- ~ay thu~ be ad~u~t-d by ~ ly rotatlng on- ~ar--n r-latlv- to th- oth-r to ehang- th- n-~h allgn~-nt ~--, for xa~pl-, FSGURES 29-30 ~howlng two ereen~ wlth parall-l mesh ~trand~ FIGURE 30 dl~clo~-~ a top plan vl-w of the two ~creQns 320B and 320C the ~trand~ of both ~cre-n~ are ln a parallol relatlon to one another FIGURE 29 how- th- ~a~ two cr--n~ 320B, 320C wher-ln one of thQ scrQQns 18 rotatQd approxl~ately 90 degree~, such that ALLEGRi~TTI ~ WITCOFF. LTO
0 SOUTII WACKeR DRIVE
CIIICAGO. ILLIN018 ~OF
TELI~ 12) 7~ 000 th- parallel strands of the two ~creens are ln an orthogonal relation~hlp to one another Thu~, by rotatlng th- ~creens 3208, 320C with respQct to each other, one may erfectively provlde a varlable aperture in th- openlng betw-en th- r-c-iv-r 44 and th-s out~ide of the hearing aid acou~tic output port 46 FIGURE 31 ~how~ a per~p-ctiv- view Or the two ~or-en~
320~, 320C, wher- on- of th-m ha- b--n rotat-d o that th- ~eoh bàrrler- are in an orthogonal relatlon-hlp to on- anoth-r Wlth th- r-latlon-hlp hown ln FlaURE 30, ~or xa~pl~ acou-tlcal l~p-danc- 1~ provld-d to th- ound wav-- ~anatlng ~ro~ th-r-a-lv-r A- two ~cr--n~ ar- rotat-d r-lativ- to on- anoth-r, how-v-r, th- acou-tlaal lmp-dana- provid-d by th- cr--n-ln¢rea-~- ~uch that, for xampl-, a ~axlmum lmp-danc- i- provld~d wlth th- cr--ne 320~, 320C arrang-d lnto th- r-latlv- po-ltlon-shown in FIGURE8 29 and 31 Thu~, th- lz- o~ th- lot- or ar-a~ b-tween th-or--n- vary to provld- a varlabl- acou-tlc l~p-danc- to th- flow o~ aound Th- poroelty of th- barrl-r~ and thue th- acou-tlc l-p-danc- of th- barrl-r 20 ~ay a-lly b- varl-d by lnply rotatlng on- o~ th- ~or--n~ 8y rotatlng th- cr-~n-, th- p-a~
of th- fr-gu-ncy r-~pon-- of the recelv-r ln the h-arlng ald are modl~led Of cource, as dl~cus~ed above, varying the width o~ the wlre used to make up the me~h wlll also vary the pos~lble lmp-dances provlded by th- scr--n~ Furth-rmor-, th~ me~h wldth may be varled to provid- a multiple layer of defen~e again~t wax AUEORETTI ~ WITCOFF Llo 10 SOUTR WACI~ER DRIVE
Cl-ICAOO. ILLIN018 00~
TEEEP110NE 1312~ 000 20~8732 ~lgratlon If, for sxample, the upper screen 320B has a greater ar-a botween strands, lt will block the flow of larger, aa~or wax partieleo The lower screen 320C may then have a smaller area b-tw--n the trand~, to bloek th- flow of ~all-r, ~lnor s partlcles o~ wax In thi~ way, eaeh ~creen provldes a re731~tance to di~f~r-nt ~lze partlcles Or wax, and the overall ~u~ceptlblllty Or th- ere-n7o to elogging beeau~e th- wax 18 reduced Th- ~ar--n- 320, 3208 and 3~0C ~y b- oolor-eod-d to r-~l-ot di~f-r-nt ~ar-en m--h d-n~ltl--, or alt~rn~tlv-ly, th-barrl-r 200 ~ay b- eolor eod-d to r-fl-at a dlf~-r-nt er--n ~--h d-n-lty ln th- v-nt th-t th- er--n 320 1- eoupl-d to barrl-r 200 by glu- or oth-r ~-an-Thu~, th- a¢ou~tle l~p-dano- ot ~ h-arlng ald ~ay b-lS ehang-d by rotatlng or--n- wlthln th- barrl-r 20 r-latlvo to on-anoth-r, r-plaolng th- barrl-r 20 wlth anoth-r barrl-r that ha- a or--n or or--n~ wlth dlff-r-nt ~--h poro-ltl--, replaolng th-Fer-ena wlthln t~- barrl-r wlth ~or--n~ that have dltf-r-nt ~esh poro~ltl-~, or r-plaolng th- barrl-r 20 wlth anoth-r ln whleh th-er-en~ ar- allgn-d ln a dl~-r-nt ~ann-r ~lth-r th- ~cr--n rl~ o~ r-plaa-abl- ~er--n~ or th- r-placeable barrl-rF
th-m~-lv-- ~ay be oolor-eod-d to r-fl-ct th- aoouFtle lmpedane-inh-r-nt to that partlcular ~creen or barrler Referrlng now to FIGURES 32 and 33, addltlonal meanE
for l~pedlng the flow of wax lnto the barrler 200 ar- ~hown FIGURF 32 lllustrates a Eubstantlally solld oap 326 havlng ~UEGRE~I ~ WITCOFF LTD

CHK,AGO, 1~ 1015 ,~.
~E~E~L' (Jl~ 7~0X

- 20~8732 ~lange~ 32a ror attaching the cap 326 to th- barrler 200 The flanges 328 provide a Elpring ~orc- extending radially outward ~rom the central axis 324 to oQcure cap 326 to barrler 200 FIGURE 33 ~how~ the cap 326 and flangeEI 328 attached to the barrler 200 The ~lang-~ 328 includo a ~ubstantially 90 d-gre- bend 330 that su~pend- th- cap 326 a ~raction o~ an lnch above the barrler 200 8ince the cap 326 xtend~ above the rest o~ the barrior 200 ~typlcally b-tw--n 0~ and 25 lnch), only a llmlt~d path exlot~ ~or wax to ent-r th- h-arlng ald r-a-lv~r 44, and acou-tla n-rgy fro th- r-a-lv-r 44 may pa-- b-tw--n a low-r portion 332 o~ aap 326 and th- lnl-t of barrl-r 200 Th- cap 326 io r-movably coupl-d to barrier 200 by n ang-~ 328 to ~acllitat- ¢l-aning and or r-moval of barri-r 200 ~ro~ h-ll 204 ~h- aap 326 may b- rabriaat-d of a pla~tlc or lS m-tal ~at-rlal R-f-rring now to FIauRE~ 34 and 3S, an alt-rnatlv-m-ane ~or aoupling barri-r 200 to h-ll 204 i- ohown In th-alt-rnativ- embodlm-nt, th- barrl-r 200 lnclud-- a plurallty o~
ubotantlally qually opaa-d, do~--~ha~-d flang-o 336 on th-hou-ing 222 A chann-l 337 xt-ndo through ach llluotrativ-ly d--lgnat-d ~lang- 336 Th- do~-d--hap-d ~lang-e 33C ar- r-celved ln a d-t-nt 338 ~ormed ln ~hell 204 Bo that collar portion 232 re~t~ on h-ll 204 The barrler 200 lo re~ovably lns-rted ln ohell 204 by applylng a forae to aollar 232 Th- channel 337 o~ the dom--ALLEl3RE~ WITCOFF. L-o 0 SOUTI- WACI~ER DRIVE
ClllCAt~. IlLINOIS tOI~
~ELEF110~ E 1312~ 71~-000 - 2Q~8732 ohaped ~lange~ 336 allow th- ~langeo 33C to d-~or~ und-r pr-s~ur~
~o that barrier 200 may be received by shell 204 By way o~ background, referrlng now to FIGURES 36-42, a barr~er driver 340 i~ shown ~or exp~dlently lnterchanglng the barrier 200 By u~lng the barrlor drlver 340, th- barrler 200 may be aslly removed and cleaned, or replac~d with a new barrler, when ar wax d-grad-~ the por~or~anc- o~ th- h-arlng al~ 22 Th- barri-r drlv-r 340 ln~lud-- a handl- 34~, barrl-r drlv-r nd 344, ànd a barri-r r-~ov-r nd 346 Th- handl- 342 lnclud-a longitudlnàl trlatlon- 34~ to provld- a non--llp grlp R-~-rrlng now to FICURE8 36-38, th- barrl-r drlv-r nd 344 lnclud-~ a ¢yllndrlcal pro~-ctlon 3S0 havlng dla~-trlcally oppo~-d ~ln~ 352A and 352B Th- pro~-ctlon 350 and ~ln~ 352A and 352B matlngly ngag- th- elot~ 23CA and 236B ot barrl-r 200 R-~-rrlng now to FIOURE9 36, 37 and 39-40, th- barrl-r reaov-r nd 346 lnclud-~ pro~-otlon~ 35~A and 35~B ln addltlon to a cyllndrlaal pro~-otlon 351, and ~lne 356A and 3S6B Th- ~ln~
356A and 356B ar- dlam-trlcally oppo--d ~or matlngly ngaglng th-oollar 232 Or barrl-r ~00, r-~o~lng on- o~ a p~urallty o~
barrl-r- 200 ~ro~ th- tray, and ln~-rtlng th- barrl-r lnto h-ll 204 o~ th- h-arlng ald 22 Varlou~ pr-~erred embodlment- o~ the pre~ent lnventlon hav- b--n de~crlb-d hereln It 1~ to b- und-r-tood, o~ course, that chang-~ and modl~icatlon~ ~ay b- mad- ln the mbodlment~
wlthout departing ~ro~ the tru- ~cop~ and splrit o~ th- pre~ent inventlon a~ de~ined by the appended claims ~UEt~ReTll ~ WITCOFF Llo SOUT11 W~CI~ER DRNE
Cl-lC~aO. ILUHOIS
TEEEF110NE 1~21~15.1000

Claims (5)

1. A barrier for a hearing aid, said hearing aid including a shell having an acoustical outlet and a receiver positioned within said shell, said receiver having a receiver outlet port and emitting sound that partially defines an acoustic response for said hearing aid, comprising: in combination:
a housing adapted to be received by said shell, said housing including a central acoustical passageway linking said acoustical outlet and said receiver outlet port, said central acoustical passageway being defined by an interior wall surface of said housing and substantially defining a central axis;
at least two projections within said central acoustical passageway, said projections being spatially and angularly displaced with respect to said central axis and cooperating to occlude a linear path through said central acoustical passageway, said two projections being substantially perpendicular to said central axis, said projections cooperatively defining trap means for providing wax accumulation sites within said housing, whereby migration of ear wax into said hearing aid is substantially retarded; and an acoustic attenuator, said acoustic attenuator and projections cooperatively defining means for damping said acoustic response of said hearing aid, said acoustic attenuator including a screen mesh for damping said acoustic response of said hearing aid, said screen mesh being comprised of substantially parallel wire strands arranged substantially in a single plane, said plane of said screen mesh being substantially perpendicular to said central axis, whereby said wire strands of said screen mesh partially occlude said central passageway and define additional trap means, providing further wax accumulation sites within said housing.

2. A barrier as claimed in claim 1 wherein said barrier is a discrete, removable component and said acoustic response of said hearing aid may be varied by removing said barrier from said hearing aid, said barrier having said screen mesh with a first screen mesh density, and replacing said barrier with a second barrier, said second barrier having a second screen mesh with a second, different screen mesh density, said damping of said frequency response of said hearing aid being dependent upon said screen mesh density.

3. A barrier as claimed in claim 1 wherein said barrier includes first and second screen meshes, each of said screen meshes being comprised of a series of substantially parallel wire strands arranged substantially in a single plane, said attenuation being variable by rotating one of said screen meshes relative to the other screen mesh to vary the alignment of said wire strands of said first and second screen meshes, whereby rotation of said screen meshes varies said acoustic attenuation of said barrier.

4. A barrier for a hearing aid, said hearing aid including a shell having an acoustical outlet and a receiver positioned within said shell, said receiver having a receiver outlet port and emitting sound that partially defines an acoustic response for said hearing aid, comprising, in combination:
a housing adapted to be received by said shell, said housing including a central acoustical passageway linking said acoustical outlet and said receiver outlet port, said central acoustical passageway being defined by an interior wall surface of said housing and substantially defining a central axis;
at least two projections within said central acoustical passageway, said projections being spatially and angularly displaced with respect to said central axis and cooperating to occlude a linear path through said central acoustical passageway, said two projections being substantially perpendicular to said central axis, said projections cooperatively defining trap means for providing wax accumulation sites within said housing, said wax accumulation sites cooperatively extending completely about said interior wall surface, whereby migration of ear wax into said hearing aid is substantially retarded, said projections including interdigitated ribs extending substantially parallel to said central axis to further impede the flow of wax between adjacent projections; and a variable acoustic attenuator, said variable acoustic attenuator and said projections cooperatively defining means for damping said acoustic response of said hearing aid.

5. A barrier as claimed in claim 4 wherein each of said interdigitated ribs are displaced along each of said projections transverse to the plane of said projections.