Can the use of the CROS system provide head shadow effect contribution to unilateral Cochlear Implant Users? / O Sistema CROS pode oferecer contribuição do efeito sombra da cabeça a usuários de implante coclear unilateral?

ABSTRACT Purpose The aim of this study was to evaluate the contribution of the CROS system on the head shadow effect in unilateral implant users. Methods Prospective cross-sectional study, approved by the ethics committee under protocol 2.128.869. Eleven adults with post-lingual deafness users of unilateral Advanced Bionics CI were selected. Speech recognition was evaluated with recorded words presented at 65dBA at 0o azimuth and at 90o on the side contralateral to the CI, with noise at 55dBA, using CI alone and CI + CROS system. The results were analyzed using paired t-test with a 0.05 alpha. Results The mean speech recognition scores were significantly better with CI + CROS in relation to the condition of CI alone (p <0.05, p <0.005 and p <0.005 respectively). In the presentation at 0o azimuth, no significant differences were found. Conclusion Users of unilateral CI without useful residual hearing for the use of hearing aids or unable to undergo bilateral surgery can benefit from the CROS device for speech recognition, especially when the speech is presented on the side contralateral to the CI.

RESUMO Objetivo O objetivo deste estudo foi avaliar o efeito do sistema CROS em fenômenos como efeito sombra da cabeça em usuários de implante coclear unilateral. Método Estudo transversal prospectivo, aprovado pelo conselho de ética sob protocolo 2.128.869. Onze adultos com surdez de instalação pós-lingual usuários de IC Advanced Bionics unilateral foram selecionados. O reconhecimento de fala foi avaliado com palavras gravadas apresentadas a 65dBA a 0o azimute e a (90o no lado contralateral ao IC), com ruído a 55dBA, usando somente o IC e IC+sistema CROS. Os resultados foram analisados usando teste t pareado com alfa de 0,05. Resultados Os escores médios de reconhecimento de fala foram significativamente melhores com IC + CROS em relação à condição apenas IC (p <0,05, p <0,005 e p <0,005 respectivamente). Na apresentação à frente não foram encontradas diferenças significantes. Conclusão Os usuários de IC unilateral sem resíduo útil para uso de prótese auditiva ou impossibilitados de submeter-se à cirurgia bilateral podem se beneficiar do dispositivo CROS para o reconhecimento de fala, sobretudo quando a fala for apresentada ao lado contralateral ao IC.

Comparison of Aided and Unaided Thresholds and Selection Processes of Contralateral Routing of Signal Hearing Aids and Implantable Bone Conduction Devices in Patients with Asymmetric Hearing Loss / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: We reviewed the selection processes of contralateral routing of signal (CROS) hearing aids (HAs) and bone-conduction (BC) Has, and compared aided and unaided hearing thresholds. SUBJECTS AND METHOD: Twenty-four patients with asymmetrical hearing loss who used BC HAs (n=12) and CROS HAs (n=12) were enrolled. The choice of two different HAs were compared with respect to the degree of hearing loss, the unaided hearing thresholds and functional gains. RESULTS: When the hearing thresholds of the better hearing ears were >30 dB HL, most (92%, 11 of 12) chose CROS rather than BC HAs, with significant difference (p=0.001). Both CROS and BC HAs groups showed significantly improved functional gains (46.6 dB and 53.4 dB, respectively). Aided air-conduction (AC) thresholds (40.2 dB HL) in the CROS group were similar to the AC thresholds (43.1 dB HL) of better hearing ears. However, the hearing threshold of Aided AC thresholds (35.8 dB HL) in BC HAs group were less than the BC thresholds (17.3 dB HL) of better hearing ears by 19 dB (p30 dB HL. The CROS group showed aided thresholds similar to the thresholds of better hearing ears, but the BC HAs group showed poorer aided thresholds than the thresholds of better hearing ears. For patients with asymmetric hearing loss, HAs should be selected based on the degree and types of hearing loss and the maximum output level of the selected device.

Hearing Rehabilitation of Single-Sided Deafness: Benefit and Selection Criteria of Bone Anchored Hearing Aid and Contralateral Routing of Signal Hearing Aid / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: There are two ways to route sound from a deaf hemifield to a functional ear: the bone anchored hearing aid (BAHA) and the contralateral routing of signal hearing aid (CROS HA). BAHA uses transcranial bone conduction; on the other hand, CROS HA uses air conduction. The objectives of this study were to evaluate the benefit of these auditory rehabilitation devices objectively and subjectively, and to analyze factors that affect daily using time. SUBJECTS AND METHOD: We retrospectively reviewed the medical records of 19 patients who selected BAHA and 9 patients who selected CROS HA to undergo rehabilitation of unilateral hearing loss. Preoperative pure tone air and bone conduction thresholds, BAHA-aided thresholds and CROS HA-aided thresholds were measured. Hearing in noise test (HINT) was measured with unaided and aided in signal to noise ratio 10 (signal 75 dB HL, noise 65 dBA). Bern Benefit in Single-Sided Deafness Questionnaire (BBSS) was evaluated for all patients to assess subjective satisfaction and also, daily device using time was investigated. RESULTS: The aided pure tone audiometry was 44.58 dB HL, 42.71 dB HL for in BAHA and CROS HA, respectively, whereas the unaided PTA was 111.29, 103.28 dB HL for BAHA and CROS HA, respectively. The aided HINT was 63.03 and 64.06%, whereas the unaided HINT was 22.13% and 37.44% for BAHA and CROS, respectively. BBSS showed more satisfactory results with BAHA and CROS HA when compared unaided in all items. Daily using time did not correlate with the degree of satisfaction, better ear hearing levels or etiology. CONCLUSION: It was found that not only the preoperative BAHA rod test and HA trials but also the customized and detail counseling were needed for single sided deaf patients to use auditory rehabilitation devices frequently.