耳鸣选择性破坏音素层面的言语感知

文献信息

中文摘要

背景： 慢性主观性耳鸣与噪声中言语感知受损有关，但其对音素层面加工的影响仍不清楚。方法：我们评估了49名听力正常参与者的音素辨别能力（26名慢性主观性耳鸣患者和23名匹配对照），其听阈和阈上加工均匹配，并使用二选一强制选择识别任务，在安静和个体化噪声条件下呈现擦音（/s, ʃ/）和塞音（/ph, t/），未发现组间在所评估的认知测量上存在统计学显著差异。结果：耳鸣组在所测试的擦音对比上表现保留（观察到的噪声准确率：0.69 vs 对照组0.73；基于模型的组间对比，p=0.778）。相比之下，塞音加工显示出选择性改变：耳鸣参与者在噪声中显著慢于对照组（模型估计 +89 ms，p=0.002），尽管观察到的准确率相当（0.47 vs 0.49；基于模型的组间对比，p=0.212）。对照组表现出明显的速度-准确性权衡（p<0.001），而耳鸣组则不存在。结论：这些发现提示耳鸣中保留的频谱加工与受损的时间加工之间存在分离。

英文摘要

Chronic subjective tinnitus has been linked to impaired speech-in-noise perception, yet its impact on phoneme level processing remains unclear. We assessed phoneme discrimination in 49 normal hearing participants (26 with chronic subjective tinnitus and 23 matched controls), with matched audiometric thresholds and supra-threshold processing, and found no statistically significant differences between groups on the assessed cognitive measures, using a two-alternative forced-choice identification task with fricatives (/s, ʃ/) and plosives (/ph, t/) presented in quiet and individualized noise conditions. Performance on the tested fricative contrast was preserved in the tinnitus group (observed noise accuracy: 0.69 vs 0.73 in controls; model based group contrast, p=0.778). In contrast, plosive processing showed a selective alteration: tinnitus participants were significantly slower than controls in noise (model estimate +89 ms, p=0.002) despite comparable observed accuracy (0.47 vs 0.49; model-based group contrast, p=0.212). Controls exhibited a clear speed-accuracy trade-off (p<0.001), which was absent in tinnitus. These findings suggest a dissociation between preserved spectral processing and impaired temporal processing in tinnitus.