Ezzatian Payam, Li Liang, Pichora-Fuller Kathy, Schneider Bruce A
1Department of Psychology, University of Toronto, Toronto, Ontario, Canada; and 2Department of Psychology, Peking University, Beijing, China.
Ear Hear. 2015 Jul-Aug;36(4):482-4. doi: 10.1097/AUD.0000000000000139.
To determine whether the time course for the buildup of auditory stream segregation differs between younger and older adults.
Word recognition thresholds were determined for the first and last keywords in semantically anomalous but syntactically correct sentences (e.g., "A rose could paint a fish") when the target sentences were masked by speech-spectrum noise, 3-band vocoded speech, 16-band vocoded speech, intact and colocated speech, and intact and spatially separated speech. A significant reduction in thresholds from the first to the last keyword was interpreted as indicating that stream segregation improved with time.
The buildup of stream segregation is slowed for both age groups when the masker is intact, colocated speech.
Older adults are more disadvantaged; for them, stream segregation is also slowed even when a speech masker is spatially separated, conveys little meaning (3-band vocoding), and vocal fine structure cues are impoverished but envelope cues remain available (16-band vocoding).
确定听觉流分离形成的时间进程在年轻人和老年人之间是否存在差异。
当目标句子被语音频谱噪声、3频段声码器语音、16频段声码器语音、完整且共置的语音以及完整且空间分离的语音掩蔽时，测定语义异常但句法正确的句子（例如，“一朵玫瑰可以画一条鱼”）中第一个和最后一个关键词的单词识别阈值。从第一个关键词到最后一个关键词阈值的显著降低被解释为表明流分离随时间得到改善。
当掩蔽声是完整且共置的语音时，两个年龄组的流分离形成都减慢。
老年人处于更不利的地位；对他们来说，即使语音掩蔽声在空间上是分离的、传达的意义很少（3频段声码）且声音精细结构线索匮乏但包络线索仍然可用（16频段声码），流分离也会减慢。
