limited trauma. With continued development and testing of thiselectrode design, the thin film array may improve the languageperception achieved through cochlear implantation.

Cochlear Implants Outcomes in Prelingually Deaf

Children

Jorge Humberto (presenter); Marisa Alves, BSc;Daniela Ramos; Luis Silva, MD; Carlos Ribeiro, MD

OBJECTIVE: 1) Assess the audiological outcomes of co-chlear implant in children with prelingual deafness. 2) Assessthe language, speech and voice outcome of cochlear implant inchildren with prelingual deafness.

METHOD: Prelingual deaf children with more than 5 years ofaural rehabilitation with cochlear implant in a Portuguese Im-plant Centre (Centro Hospitalar de Coimbra), from 1992 to2009, were submitted to tonal and vocal functional gain, dis-crimination tests adapted to the age of the individuals, auditorycomprehension, speech and language. The monosyllables,numbers and sentences discrimination tests (Portuguese Euro-pean Language tests) were presented in free field with recordedlists using SFS software through the audiometer at 65 dB SPL.The scales CAP and SIR, Portuguese test that evaluates lan-guage development (Compreenso de Estruturas Complexas)speech production (Teste de Articulao Verbal), vocal charac-teristics (Grelha de Avaliao das Caractersticas Vocais -GACV) and a vowel discrimination test were also used.

RESULTS: 142 individuals were evaluated with the mono-syllables discrimination test; 78.1% achieved 50% discrimina-tion; 41.5% achieved 70%; regarding phonemic discrimina-tion, mean of 76.25 is achieved, median 81.40 and standarddeviation 17.87 . 142 individuals were evaluated with thenumbers discrimination test; 96.5% achieved 50% discrimina-tion; 90% achieved 70%, regarding phonemic discriminationmean of 93 is achieved, median 98.85 and standard deviation13.97. 142 individuals were evaluated with the sentences dis-crimination test; 76% achieved 50% discrimination; 51.9%achieved 70% discrimination. 133 individuals were evaluatedwith the vowel discrimination test; the results were an averageof 97.42%, and standard deviations of 11.04. 190 individualswere evaluated with the SIR scale; 13.2% were scored on level3, 16.8% on level 4, and 58.9% on level 5. 127 individualswere evaluated with the CAP scale; 28.3% were scored onlevel 4, 30.7% on level 5, 17.3% on level 6, and 22% on level7. 209 individuals were evaluated with the GACV scale; 4.3%were scored on level 3, 34% on level 4 and 58.4% on level 5.Complex sentence comprehension test (Teste de Compreensode Estruturas Complexas) (n�100) the results were an averageof 61.67%, and standard deviations of 26.5. Speech productiontest (Teste de Articulao Verbal) (N�171) the results were anaverage of 77.6%, and standard deviations of 20.85.

CONCLUSION: The results express a good performance inspeech intelligibility, with a good articulation level and a good

voice quality, according to the results published by other in-ternational cochlear implant centers.

Cochlear Microcirculation and Hearing Function

After Noise

Sebastian Strieth, MD (presenter); Martin Canis;Markus Suckfuell; Alexander Berghaus, MD;Warangkana Arpornchayanon

OBJECTIVE: 1) Understand how microcirculatory distur-bances are linked to hearing function of the inner ear afternoise injury. 2) Establish a new standardized animal model forin vivo analysis of cochlear microcirculation and hearing func-tion after noise injury.METHOD: In an experimental study using guinea pigs (n�6)normal hearing thresholds on both ears were verified (0 min)by evoked auditory brainstem responses (ABR). After appli-cation of loud noise (106 dB SPL) on both ears for 30 min thecochlea was surgically exposed on one side and in vivo fluo-rescence microscopy of stria vascularis capillaries was per-formed. In addition, simultaneous ABR measurements werederived from the contralateral ear. Animals without noise ex-posure served as controls (n�6).RESULTS: After noise exposure, red blood cell velocity de-creased to 44.5 �/- 3.4 % of baseline values at the end ofobservation period (210 min) in contrast to stable controlmeasurements. With regard to unaffected vessel diameters inboth groups a gradual decrease of segmental blood flow (38.1�/- 8.2 % of baseline values) became significant 150 min afternoise exposure comparing with controls. Hearing thresholdsshifted significantly from 20.0 �/- 5.5 dB SPL (0 min) to 45.0�/- 4.5 dB SPL (210 min) only in animals exposed to loudnoise.CONCLUSION: A new standardized model for inner earmicrocirculatory disturbance and hearing threshold shift afteracute loud noise was established. This method allows us toanalyze in detail effects and kinetics of rheological treatmentstargeted on inner ear microcirculation with regard to the hear-ing function in vivo.

Comparison of Muzzle Suppression and Ear-Level

Protection

Matthew Branch, MD (presenter)

OBJECTIVE: To compare noise reduction of commerciallyavailable ear-level hearing protection (muffs/inserts) to that offirearm muzzle suppressors.METHOD: Multiple muzzle suppressors for two pistol andtwo rifle calibers were tested using B&K 2209 sound meterand B&K 4136 microphone calibrated with B&K Pistophoneusing Mil-Std 1474D placement protocol. Five shots wererecorded unsuppressed and five shots suppressed under con-sistent environmental conditions. Sound reduction was then

P90 Otolaryngology-Head and Neck Surgery, Vol 143, No 2S2, August 2010