Northwestern University, Evanston, IL, USA.
J Speech Lang Hear Res. 2012 Apr;55(2):474-86. doi: 10.1044/1092-4388(2011/10-0238). Epub 2011 Dec 29.
In view of previous findings (Bor, Souza, & Wright, 2008) that some listeners are more susceptible to spectral changes from multichannel compression (MCC) than others, this study addressed the extent to which differences in effects of MCC were related to differences in auditory filter width.
Listeners were recruited in 3 groups: listeners with flat sensorineural loss, listeners with sloping sensorineural loss, and a control group of listeners with normal hearing. Individual auditory filter measurements were obtained at 500 and 2000 Hz. The filter widths were related to identification of vowels processed with 16-channel MCC and with a control (linear) condition.
Listeners with flat loss had broader filters at 500 Hz but not at 2000 Hz compared with listeners with sloping loss. Vowel identification was poorer for MCC compared with linear amplification. Listeners with flat loss made more errors than listeners with sloping loss, and there was a significant relationship between filter width and the effects of MCC.
Broadened auditory filters can reduce the ability to process amplitude-compressed vowel spectra. This suggests that individual frequency selectivity is a factor that influences benefit of MCC when a high number of compression channels are used.
鉴于先前的研究发现(Bor、Souza 和 Wright,2008),一些听众比其他人更容易受到多通道压缩(MCC)的频谱变化的影响,本研究探讨了 MCC 效果差异与听觉滤波器宽度差异之间的关系程度。
研究招募了三组听众:具有平坦感音神经性损失的听众、具有倾斜感音神经性损失的听众和具有正常听力的对照组听众。在 500Hz 和 2000Hz 处获得个体听觉滤波器测量值。滤波器宽度与使用 16 通道 MCC 和对照(线性)条件处理的元音识别相关。
与倾斜损失的听众相比,500Hz 时平坦损失的听众的滤波器较宽,但在 2000Hz 时则不然。与线性放大相比,MCC 对元音的识别效果较差。与倾斜损失的听众相比,平坦损失的听众犯的错误更多,并且滤波器宽度与 MCC 的影响之间存在显著关系。
听觉滤波器的变宽会降低处理幅度压缩元音频谱的能力。这表明,当使用大量压缩通道时,个体频率选择性是影响 MCC 益处的一个因素。