Coughlin M, Kewley-Port D, Humes L E
Department of Speech and Hearing Sciences, Indiana University, Bloomington 47405, USA.
J Acoust Soc Am. 1998 Dec;104(6):3597-607. doi: 10.1121/1.423942.
This study examined both the identification and discrimination of vowels by three listener groups: elderly hearing-impaired, elderly normal-hearing, and young normal-hearing. Each hearing-impaired listener had a longstanding symmetrical, sloping, mild-to-moderate sensorineural hearing loss. Two signal levels [70 and 95 dB sound-pressure level (SPL)] were selected to assess the effects of audibility on both tasks. The stimuli were four vowels, /I,e, epsilon, ae/, synthesized for a female talker. Difference limens (DLs) were estimated for both F1 and F2 formants using adaptive tracking. Discrimination DLs for F1 formants were the same across groups and levels. Discrimination DLs for F2 showed that the best formant resolution was for the young normal-hearing group, the poorest was for the elderly normal-hearing group, and resolution for the elderly hearing-impaired group fell in between the other two at both signal levels. Only the elderly hearing-impaired group had DLs that were significantly poorer than those of the young listeners at the lower, 70 dB, level. In the identification task at both levels, young normal-hearing listeners demonstrated near-perfect performance (M = 95%), while both elderly groups were similar to one another and demonstrated lower performance (M = 71%). The results were examined using correlational analysis of the performance of the hearing-impaired subjects relative to that of the normal-hearing groups. The results suggest that both age and hearing impairment contribute to decreased vowel perception performance in elderly hearing-impaired persons.
老年听力受损者、老年听力正常者和年轻听力正常者。每位听力受损的听众都患有长期对称、呈斜坡状的轻至中度感音神经性听力损失。选择了两个信号强度[70和95分贝声压级（SPL）]来评估可听度对这两项任务的影响。刺激音为为一名女性说话者合成的四个元音，/I,e, epsilon, ae/。使用自适应跟踪法估计了第一共振峰（F1）和第二共振峰（F2）的差别阈限（DLs）。F1共振峰的辨别差别阈限在不同组和不同强度下是相同的。F2的辨别差别阈限表明，最佳的共振峰分辨率出现在年轻听力正常组，最差的出现在老年听力正常组，老年听力受损组在两个信号强度下的分辨率介于另外两组之间。只有老年听力受损组在较低的70分贝强度下的差别阈限明显比年轻听众差。在两个强度水平的识别任务中，年轻听力正常的听众表现近乎完美（M = 95%），而两个老年组彼此相似且表现较差（M = 71%）。通过对听力受损受试者与听力正常组表现的相关性分析来检验结果。结果表明，年龄和听力损伤都导致老年听力受损者元音感知能力下降。
