Summary: | 碩士 === 國立高雄師範大學 === 聽力學與語言治療研究所 === 99 === The aims of this study were to explore the reliability of Mandarin ANL test (M-ANL), the effects of wearing hearing aids and noise reduction features (NRF) (directional microphone and digital noise reduction system) in M-ANL test, and to find out which one, (three patterns of hearing-aid usage v.s. percentage of hearing-aid use) is more appropriate in predicting the frequency of hearing-aid use via ANL values. The established relationship between M-ANL and the frequency of hearing-aid use will provide clinicians a tool in predicting how often the hearing aids will be used even before hearing-aid evaluation. The M-ANL test and the questionnaire of hearing-aid use were the basic tools of the study. Participants were hearing-impaired adults and they all had experiences of wearing hearing aids. Three experiments were designed to achieve different purposes. Participants were 25, 43, and 122 for experiment I to III, respectively. Results showed that (1) The M-ANL test had good reliability, and it took 15 minutes to finish the test (including introduction and assessment); (2) The ANL values measured in aided condition with NRF on were significant lower than both in unaided condition and in aided condition with NRF off. The difference between them was about 1.72 dB (p<.05); (3) M-ANL values could not discriminate among the three patterns of hearing-aid usage: full-time users, part-time users, and non-users; (4) M-ANL values could explain the variation of the percentage of hearing-aid usage only about 25.4 % (for aided group with NRF off) and 18.4 % (for aided group with NRF on). Furthermore, better ear’s average hearing thresholds could provide additional 13 % variance for aided with NRF off, but not for the other group. (5) If subjects’ use of hearing aids were equal or higher than 67 %, they would be assigned to the high-use group; otherwise, they would be assigned to the low-use group. Logistic regression curves pointed out that if unaided ANL values<5 dB, there would be more than 85% of the probability to become a hearing-aid user with high-frequency of usage, in addition, unaided ANL values>13 dB for aided group with NRF off, and unaided ANL values>17 dB for aided group with NRF on, they would easily become a hearing-aid user with low-frequency of usage (the odds of becoming a high-frequency user was less than 20 %). Regression analysis indicated that unaided ANL values could predict hearing-aid usage patterns with 86.0 % (aided group with NRF off) and 81.9 % (aided group with NRF on) of accuracy. The most important finding of this study is that wearing a hearing aid with NRF-on will change and reduce M-ANL values, therefore, establishing a corresponding relationship between ANL and frequency of hearing-aid use should consider the potential effects of hearing-aid features.
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