Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, USA. p-souza@ northwestern.edu
Ear Hear. 2010 Apr;31(2):268-76. doi: 10.1097/AUD.0b013e3181c9fb9c.
In previous work, a simplified version of the modulation spectrum, the Spectral Correlation Index, was shown to be related to consonant error patterns. It is unknown what effect clinical amplification strategies will have on the modulation spectrum. Accordingly, the goals of this study were to examine the effect of clinical amplification strategies on the consonant modulation spectrum and to determine whether there was a relationship between the modulation spectrum and consonant errors for spectrally robust, amplified speech presented to listeners with hearing loss.
Participants were 13 adults (mean age, 67 yrs) with mild to moderate sensorineural hearing loss. Each listener was fit monaurally in the test ear with a 16-band, four-channel behind the ear hearing aid. One memory of the hearing aid was programmed with compression limiting amplification and one with fast-acting wide-dynamic range compression (WDRC) amplification. Twenty-two consonant-vowel syllables were presented to the listener and recorded at the output of the hearing aid using a probe microphone system. A modulation spectrum was obtained for each amplified and unamplified consonant-vowel. Consonant recognition was also measured for each listener.
Results show that (1) WDRC increased heterogeneity of the modulation spectrum across consonants and (2) for spectrally robust speech processed with either compression limiting or WDRC amplification, two consonants with similar modulation spectra are more likely to be confused with one another than are the two consonants with dissimilar modulation spectra.
These data expand and confirm earlier results linking the modulation spectrum to specific consonant errors.
在之前的工作中，调制谱的简化版本——频谱相关指数，被证明与协同错误模式有关。目前尚不清楚临床放大策略会对调制谱产生什么影响。因此，本研究的目的是研究临床放大策略对协同调制谱的影响，并确定调制谱与听力损失患者听到的频谱稳健放大语音的协同错误之间是否存在关系。
参与者为 13 名成年人（平均年龄，67 岁），患有轻度至中度感音神经性听力损失。每位听众在测试耳中均使用 16 频段、四通道耳后助听器进行单耳验配。助听器的一个记忆被编程为压缩限制放大，另一个记忆被编程为快速作用宽动态范围压缩（WDRC）放大。向听众呈现 22 个辅音-元音音节，并使用探头麦克风系统在助听器的输出端进行录制。为每个放大和未放大的辅音-元音获得调制谱。也为每位听众测量了协同识别。
结果表明：（1）WDRC 增加了辅音间调制谱的异质性；（2）对于使用压缩限制或 WDRC 放大处理的频谱稳健语音，具有相似调制谱的两个辅音比具有不同调制谱的两个辅音更有可能相互混淆。
这些数据扩展并证实了先前将调制谱与特定协同错误联系起来的结果。
