청각기능에 영향을 주는 청취환경은 청각기능의 상태를 직간접적으로 나타내는변수로 사용될 수가 있다. 이 주요 청취환경 변수 중에서 소음과 반향이 있으며, 청각인지과정에 미치는 영향이 다양하다. 그 예로 정상청력을 가진 성인의 경우에도 청취 환경에 존재하는 소음은 어음처리능력에 기 능적인 손실을 가져오고,3) 반향도 유사한 경향을 보인다.7)8) 동일한 조건에서, 감각신경성 난청인들은 이러한 신호의 왜곡에 대하여 정상인들보다 더 영향을 받는 것으로 보고되 고 있다.7)8) 노인성 난청에서도 일반적인 감각신경성 난청과 비슷한 결과가 보고되고 있다.9)10) 특히, 실제 청취환경
The reverberation time (RT60) was known as one of the major environmental variables that could affect auditory performances. The purpose of this study was to investigate the effects of reverberation times and S/N ratios on discrimination scores of monosyllabic words in normal and elderly adults. The participated subjects were eleven normal (with the mean age of 20.5 and mean HL of 1.7 dB) and five elderly adults (with the mean age of 74.8 and mean HL of 38.4 dB. The reverberation time was digitally synthesized using Sabine equation and the test set were RTs of 0, 24, 480, 960, 1,920, and 3,840 msec. The combined signal to noise ratios were at the levels of -10, 0, and +10 dB with both contralateral and ipsilateral conditions. The results showed that monosyllabic word discrimination scores were significantly influenced by reverberation times and S/N ratios. The elderly adults with reduced hearing status exhibited greater difficulties as reverberation times increased and S/N ratios reduced. In these experimental groups, discrimination scores reached the peak values at the positive RTs and the performance scores were deteriorated thereafter. This influence of noise was pronounced under ipsilateral conditions. In conclusion, the degree and level of these discrepancies from those of normal subjects appeared to be reliable quantitative indicators of higher levels of functional hearing status and could be used as practical performance measures in auditory training and rehabilitation programs. KEY WORDS：Reverberation time·Signal to noise ratio·Word recognition score.
INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSIONS CONCLUSIONS REFERENCES
