Doherty K A, Lutfi R A
Communication Sciences and Disorders, Syracuse University, New York 13244, USA.
J Acoust Soc Am. 1999 Mar;105(3):1831-40. doi: 10.1121/1.426742.
A conditional-on-a-single-stimulus (COSS) analysis procedure [B. G. Berg, J. Acoust. Soc. Am. 86, 1743-1746 (1989)] was used to estimate how well normal-hearing and hearing-impaired listeners selectively attend to individual spectral components of a broadband signal in a level discrimination task. On each trial, two multitone complexes consisting of six octave frequencies from 250 to 8000 Hz were presented to listeners. The levels of the individual tones were chosen independently and at random on each presentation. The target tone was selected, within a block of trials, as the 250-, 1000-, or 4000-Hz component. On each trial, listeners were asked to indicate which of the two complex sounds contained the higher level target. As a group, normal-hearing listeners exhibited greater selectivity than hearing-impaired listeners to the 250-Hz target, while hearing-impaired listeners showed greater selectivity than normal-hearing listeners to the 4000-Hz target, which is in the region of their hearing loss. Both groups of listeners displayed large variability in their ability to selectively weight the 1000-Hz target. Trial-by-trial analysis showed a decrease in weighting efficiency with increasing frequency for normal-hearing listeners, but a relatively constant weighting efficiency across frequency for hearing-impaired listeners. Interestingly, hearing-impaired listeners selectively weighted the 4000-Hz target, which was in the region of their hearing loss, more efficiently than did the normal-hearing listeners.
采用单刺激条件（COSS）分析程序[B.G.伯格，《美国声学学会杂志》86, 1743 - 1746（1989）]来估计听力正常和听力受损的听众在电平辨别任务中对宽带信号的各个频谱成分进行选择性注意的程度。在每次试验中，向听众呈现由250至8000赫兹的六个倍频程频率组成的两个多音复合音。每次呈现时，各个音调的电平是独立且随机选择的。在一组试验中，目标音调被选定为250赫兹、1000赫兹或4000赫兹的成分。每次试验时，要求听众指出两个复合声音中哪个包含更高电平的目标音。总体而言，听力正常的听众对250赫兹目标音的选择性高于听力受损的听众，而听力受损的听众对4000赫兹目标音（处于他们听力损失区域）的选择性高于听力正常的听众。两组听众在对1000赫兹目标音进行选择性加权的能力上都表现出很大的变异性。逐次试验分析表明，听力正常的听众的加权效率随频率增加而降低，而听力受损的听众在不同频率下的加权效率相对恒定。有趣的是，听力受损的听众对处于其听力损失区域的4000赫兹目标音的选择性加权比听力正常的听众更有效。
