補聴器装用が高齢難聴者の語音聴取能に及ぼす影響

The effect of hearing aids on speech intelligibility in senior adults with hearing loss

　【目的】感音難聴のある補聴器装用群・非装用群の二群間における時間分解能，最高語音明瞭度，注意機能（PASAT），不快レベルの違いを比較検討すること．

　【方法】対象は当院耳鼻咽喉科外来へ通院している両側感音難聴のある65歳以上の補聴器装用20人と非装用22人である．

　【結果】補聴器装用群は非装用群に比し不快レベルの閾値が有意に上昇していた（500Hz：97.5dB，p＝0.007；1,000Hz：95dB，p＝0.001；2,000Hz：100dB，p＝0.006）．時間分解能や最高語音明瞭度，注意機能に関しては，補聴器装用群と非装用群で有意差を認めなかった．また不快レベルと最高語音明瞭度において有意な相関を認めた（r＝0.36，p＝0.020）．

　【考察】補聴器装用群は29.5月の装用期間により，音の大きさへの順応で不快レベルの閾値が上昇したと考える．不快閾値が上昇することで，最高語音明瞭度が改善するかについてはさらに検討が必要と考える．

　Speech comprehension involves a variety of skills. In this study, we investigated whether wearing hearing aids in sensorineural hearing loss would result in changes in temporal resolution, maximum speech intelligibility, attention function, and uncomfortable loudness level. The subjects were 20 hearing aid wearers and 22 non-wearers, all aged 65 or older, with bilateral sensorineural hearing loss who attended the otolaryngology department of our hospital as outpatients. We found that the value of uncomfortable loudness level was significantly higher in the hearing aid group than in the non-hearing aid group (500Hz：97.5dB, p=0.007 ; 1,000Hz：95dB, p=0.001 ; 2,000Hz：100dB, p=0.006). The elevated uncomfortable loudness level is believed to be the result of adaptation to the loudness of sounds while wearing hearing aids. No significant differences were found between the two subject groups in terms of temporal resolution, maximum speech intelligibility, or attention function. We also examined the relationship between gap detection threshold, maximum speech intelligibility, attention function, and uncomfortable loudness level. The results showed a significant correlation between uncomfortable loudness level and maximum speech intelligibility (r=0.36, p=0.020).