난청인이 보청기를 착용했을 때 자신의 목소리가 울려서 들 리는 폐쇄효과(occlusion effect)는 주로 저주파수에서 경도 전 후의 청력역치레벨을 가진 난청인이 어려움을 호소한다(Carle et al., 2002; Dillon, 2012; Kiessling et al., 2005). 폐쇄효과의 발생원인은 성대의 울림이 하악 및 두개골(skull)을 통하여 외이 도 내에서 재생성되고 이 음압이 난청인이 착용한 보청기로 인 해 외이도 밖으로 배출되지 못하고 고막으로 전달되어 발생한 다. 폐쇄효과의 발생은 주로 고주파수보다는 낮은 저주파수 대 역의 어음을 발성할 때 발생하는데, 연구에 따르면 발성 시 입술 또는 치아가 닫히며, 제1포먼트가 300 Hz 내외인 /이/, /우/ 등의 어음에서 주로 발생한다(Dillon, 2012; Lee & Lee, 2013).
Purpose: One of the main complaints in hearing aid users is the abnormal perception of their voices, which is known as occlusion effect. Open fit hearing aids, for example, receiver-in-the-canal (RIC) hearing aid type is a good solution to the occlusion effect. However, here, two subjects avoid using RIC due to cosmetic unsatisfaction and difficulty of using a cell phone. The purpose of this study was to investigate the possibility of reducing the occlusion effect and improving cell phone usage and cosmetic satisfaction using invisible-inthe- canal (IIC) hearing aids. Methods: Two hearing impaired listeners who used bilateral RIC type hearing aids participated. IIC hearings were manufactured. Functional gain, real ear insertion gains, word recognition scores and a subjective hearing aids benefit questionnaire were assessed with RIC and IIC hearing aids, respectively. Subjective occlusion effect was also measured. Results: There were no differences in functional and insertion gains between two types of hearing aids. Participants did not complain the occlusion effect with IIC hearing aids. Conclusion: Although RIC hearing aids have an advantage of reducing the occlusion effects in both participants, they preferred to wear IIC hearing aids due to comforting of using a cell phone and cosmetic reasons. Results of the current study showed objective and subjective functions of RIC and IIC hearing aids were not different each other in both participants. The RIC hearing aid type, open-fit hearing aid, is not the only one option for reducing the occlusion effects; audiologists should consider the individual’s needs.
INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSIONS REFERENCES
