PDF(Pubmed)
Abstract：
Advancing age is associated with decreased sensitivity to temporal cues in word segments, particularly when target words follow non-informative carrier sentences or are spectrally degraded (e.g., vocoded to simulate cochlear-implant stimulation). This study investigated whether age, carrier sentences, and spectral degradation interacted to cause undue difficulty in processing speech temporal cues. Younger and older adults with normal hearing performed phonemic categorization tasks on two continua: a Buy/Pie contrast with voice onset time changes for the word-initial stop and a Dish/Ditch contrast with silent interval changes preceding the word-final fricative. Target words were presented in isolation or after non-informative carrier sentences, and were unprocessed or degraded via sinewave vocoding (2, 4, and 8 channels). Older listeners exhibited reduced sensitivity to both temporal cues compared to younger listeners. For the Buy/Pie contrast, age, carrier sentence, and spectral degradation interacted such that the largest age effects were seen for unprocessed words in the carrier sentence condition. This pattern differed from the Dish/Ditch contrast, where reducing spectral resolution exaggerated age effects, but introducing carrier sentences largely left the patterns unchanged. These results suggest that certain temporal cues are particularly susceptible to aging when placed in sentences, likely contributing to the difficulties of older cochlear-implant users in everyday environments.
摘要：
年龄的增长与对词段中时间线索的敏感性降低有关，特别是当目标单词遵循非信息载体句子或光谱退化时(例如，声编码以模拟人工耳蜗刺激)。这项研究调查了年龄，载体句子，和频谱退化相互作用，导致处理语音时间线索的困难。听力正常的年轻人和老年人在两个连续数上执行了音素分类任务：Buy/Pie对比度与单词初始停止的声音发作时间变化，以及Dish/Ditch对比度与单词最终摩擦音之前的无声间隔变化。目标词是孤立地或在非信息载体句之后呈现的，并且未经处理或通过正弦波声编码（2、4和8通道）降级。与年轻的听众相比，年龄较大的听众对两种时间线索的敏感性均降低。对于购买/馅饼的对比，年龄,承运人句子，和频谱退化相互作用，使得在载体句子条件下，未处理的单词的年龄效应最大。这种模式与碟子/沟渠对比不同，降低光谱分辨率夸大了年龄影响，但是引入载体句子在很大程度上使模式保持不变。这些结果表明，某些时间线索在句子中放置时特别容易老化，可能导致老年人工耳蜗使用者在日常环境中的困难。
