Department of Speech, Language and Hearing Sciences and Hearing Research Center, Boston University, Boston, MA 02215, USA.
J Assoc Res Otolaryngol. 2013 Aug;14(4):603-10. doi: 10.1007/s10162-013-0392-1. Epub 2013 May 7.
This study tested the hypothesis that energetic masking limits the benefits obtained from spatial separation in multiple-talker listening situations, particularly for listeners with sensorineural hearing loss. A speech target was presented simultaneously with two or four speech maskers. The target was always presented diotically, and the maskers were either presented diotically or dichotically. In dichotic configurations, the maskers were symmetrically placed by introducing interaural time differences (ITDs) or infinitely large interaural level differences (ILDs; monaural presentation). Target-to-masker ratios for 50 % correct were estimated. Thresholds in all separated conditions were poorer in listeners with hearing loss than listeners with normal hearing. Moreover, for a given listener, thresholds were similar for conditions with the same number of talkers per ear (e.g., ILD with four talkers equivalent to ITD with two talkers) and hence the same energetic masking. The results are consistent with the idea that increased energetic masking, rather than a specific spatial deficit, may limit performance for hearing-impaired listeners in spatialized speech mixtures.
本研究检验了一个假设，即能量掩蔽限制了多说话人聆听环境中空间分离所带来的益处，特别是对于感音神经性听力损失的聆听者。一个语音目标与两个或四个语音掩蔽同时呈现。目标总是以立体声呈现，而掩蔽可以以立体声或立体声呈现。在立体声配置中，通过引入耳间时间差 (ITD) 或无限大的耳间水平差 (ILD；单耳呈现) 来对称放置掩蔽。估计了 50%正确的目标到掩蔽比率。听力损失者在所有分离条件下的阈值均低于正常听力者。此外，对于给定的聆听者，具有相同数量的说话者（例如，四个说话者的 ILD 相当于两个说话者的 ITD）的条件下的阈值相似，因此具有相同的能量掩蔽。这些结果与这样一种观点一致，即能量掩蔽的增加，而不是特定的空间缺陷，可能会限制听力受损聆听者在空间化语音混合中的表现。
