Baltzell Lucas S, Swaminathan Jayaganesh, Cho Adrian Y, Lavandier Mathieu, Best Virginia
Department of Speech, Language, and Hearing Sciences, Boston University, 635 Commonwealth Avenue, Boston, Massachusetts 02215, USA.
University of Lyon, ENTPE, Laboratoire Génie Civil et Bâtiment, Rue Maurice Audin, F-69518 Vaulx-en-Velin Cedex, France.
J Acoust Soc Am. 2020 Mar;147(3):1546. doi: 10.1121/10.0000812.
Listeners with sensorineural hearing loss routinely experience less spatial release from masking (SRM) in speech mixtures than listeners with normal hearing. Hearing-impaired listeners have also been shown to have degraded temporal fine structure (TFS) sensitivity, a consequence of which is degraded access to interaural time differences (ITDs) contained in the TFS. Since these "binaural TFS" cues are critical for spatial hearing, it has been hypothesized that degraded binaural TFS sensitivity accounts for the limited SRM experienced by hearing-impaired listeners. In this study, speech stimuli were noise-vocoded using carriers that were systematically decorrelated across the left and right ears, thus simulating degraded binaural TFS sensitivity. Both (1) ITD sensitivity in quiet and (2) SRM in speech mixtures spatialized using ITDs (or binaural release from masking; BRM) were measured as a function of TFS interaural decorrelation in young normal-hearing and hearing-impaired listeners. This allowed for the examination of the relationship between ITD sensitivity and BRM over a wide range of ITD thresholds. This paper found that, for a given ITD sensitivity, hearing-impaired listeners experienced less BRM than normal-hearing listeners, suggesting that binaural TFS sensitivity can account for only a modest portion of the BRM deficit in hearing-impaired listeners. However, substantial individual variability was observed.
与听力正常的听众相比，感音神经性听力损失的听众在语音混合中通常经历较少的掩蔽空间释放（SRM）。听力受损的听众也被证明具有退化的时间精细结构（TFS）敏感性，其结果是对TFS中包含的双耳时间差（ITD）的获取能力下降。由于这些“双耳TFS”线索对空间听觉至关重要，因此有人推测，双耳TFS敏感性的退化是听力受损听众SRM受限的原因。在本研究中，语音刺激通过在左耳和右耳之间系统地去相关的载波进行噪声编码，从而模拟退化的双耳TFS敏感性。在年轻的听力正常和听力受损的听众中，测量了（1）安静环境下的ITD敏感性和（2）使用ITD进行空间定位的语音混合中的SRM（或掩蔽双耳释放；BRM），作为TFS双耳去相关的函数。这使得能够在广泛的ITD阈值范围内检查ITD敏感性和BRM之间的关系。本文发现，对于给定的ITD敏感性，听力受损的听众比听力正常的听众经历的BRM更少，这表明双耳TFS敏感性只能解释听力受损听众BRM缺陷的一小部分。然而，观察到了显著的个体差异。
