Hong Robert S, Turner Christopher W
Department of Otolaryngology-Head and Neck Surgery, University of Iowa, 121B WJSHC, Iowa City, Iowa 52242-1012, USA.
J Acoust Soc Am. 2006 Jul;120(1):360-74. doi: 10.1121/1.2204450.
This study examined the ability of cochlear implant users and normal-hearing subjects to perform auditory stream segregation of pure tones. An adaptive, rhythmic discrimination task was used to assess stream segregation as a function of frequency separation of the tones. The results for normal-hearing subjects were consistent with previously published observations (L.P.A.S van Noorden, Ph.D. dissertation, Eindhoven University of Technology, Eindhoven, The Netherlands 1975), suggesting that auditory stream segregation increases with increasing frequency separation. For cochlear implant users, there appeared to be a range of pure-tone streaming abilities, with some subjects demonstrating streaming comparable to that of normal-hearing individuals, and others possessing much poorer streaming abilities. The variability in pure-tone streaming of cochlear implant users was correlated with speech perception in both steady-state noise and multi-talker babble. Moderate, statistically significant correlations between streaming and both measures of speech perception in noise were observed, with better stream segregation associated with better understanding of speech in noise. These results suggest that auditory stream segregation is a contributing factor in the ability to understand speech in background noise. The inability of some cochlear implant users to perform stream segregation may therefore contribute to their difficulties in noise backgrounds.
本研究考察了人工耳蜗使用者和听力正常受试者对纯音进行听觉流分离的能力。采用一种自适应的节奏辨别任务来评估作为音调频率分离函数的流分离情况。听力正常受试者的结果与先前发表的观察结果一致（L.P.A.S范诺登，博士论文，荷兰埃因霍温理工大学，埃因霍温，1975年），表明听觉流分离随着频率分离的增加而增强。对于人工耳蜗使用者而言，似乎存在一系列纯音流分离能力，一些受试者表现出与听力正常个体相当的流分离能力，而另一些受试者的流分离能力则差得多。人工耳蜗使用者纯音流分离的变异性与稳态噪声和多说话者嘈杂环境中的言语感知相关。在流分离与两种噪声环境下言语感知测量之间观察到中度的、具有统计学意义的相关性，流分离越好与噪声环境中言语理解越好相关。这些结果表明，听觉流分离是在背景噪声中理解言语能力的一个促成因素。因此，一些人工耳蜗使用者无法进行流分离可能导致他们在噪声环境中遇到困难。
