Bor Stephanie, Souza Pamela, Wright Richard
Hearing Aid Laboratory, Department of Speech and Hearing Sciences, University of Washington, 1417 N.E. 42nd Street, Box 354875, Seattle, WA 98105-6246, USA.
J Speech Lang Hear Res. 2008 Oct;51(5):1315-27. doi: 10.1044/1092-4388(2008/07-0009). Epub 2008 Jul 29.
To clarify if large numbers of wide dynamic range compression channels provide advantages for vowel identification and to measure its acoustic effects. Methods Eight vowels produced by 12 talkers in the /hVd/ context were compressed using 1, 2, 4, 8, and 16 channels. Formant contrast indices (mean formant peak minus mean formant trough; maximum formant peak minus minimum formant trough) were developed to quantify spectral changes. Twenty listeners with mild to moderately severe sensorineural hearing loss identified the compressed vowels in an 8-alternative forced-choice procedure.
Formant contrast measures revealed significant spectral flattening for 6 of the 8 vowels as channel number increased. A significant decrease in vowel identification performance was also observed as spectral contrast decreased.
Increasing the number of wide dynamic range compression channels may not be beneficial for all speech signals, and individual vowel identification performance can vary greatly for listeners with similar hearing loss.
阐明大量宽动态范围压缩通道是否能为元音识别带来优势，并测量其声学效果。方法对12名说话者在/hVd/语境下发出的8个元音使用1、2、4、8和16个通道进行压缩。开发了共振峰对比度指数（平均共振峰峰值减去平均共振峰谷值；最大共振峰峰值减去最小共振峰谷值）来量化频谱变化。20名轻度至中度重度感音神经性听力损失的听众在8选1的强制选择程序中识别压缩后的元音。
共振峰对比度测量显示，随着通道数量增加，8个元音中有6个出现了显著的频谱扁平化。随着频谱对比度降低，元音识别性能也显著下降。
增加宽动态范围压缩通道的数量可能并非对所有语音信号都有益，对于听力损失程度相似的听众，个体的元音识别性能可能差异很大。
