Chung King, Killion Mead C, Christensen Laurel A
Northwestern University, New York, USA.
J Speech Lang Hear Res. 2007 Apr;50(2):304-22. doi: 10.1044/1092-4388(2007/022).
To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss.
Peak clipping, compression limiting, and 4 wide dynamic range compression (WDRC) input-output functions were compared in a repeated-measure design. Interactions among the compression characteristics were minimized. Speech and babble were processed and recorded at 3 input levels: 45, 65, and 90 dB sound pressure level. Speech recognition of 3 groups of listeners (n = 6/group) was tested for speech processed by each input-output function and at each input level.
Input-output functions that made low-level speech audible and high-level speech less distorted by avoiding peak clipping or severe compression yielded higher speech recognition scores. These results are consistent with previous findings in the literature.
WDRCs with the low compression ratio region extended to a high input level or with a high compression limiting threshold were the best for speech recognition in babble when the hearing aid user cannot or does not want to manipulate the volume control. Future studies on subjective preferences of different input-output functions are needed.
确定6种输入-输出函数对于听力正常者、平坦型感音神经性听力损失者和轻度斜坡型感音神经性听力损失者在多说话者嘈杂环境中理解低声级、对话级和高声级语音的排名，且不操作音量控制。
在重复测量设计中比较了峰值削波、压缩限制和4种宽动态范围压缩（WDRC）输入-输出函数。压缩特性之间的相互作用被最小化。语音和嘈杂声在3个输入电平下进行处理和记录：45、65和90分贝声压级。对3组听众（每组n = 6）进行语音识别测试，测试每种输入-输出函数在每个输入电平下处理的语音。
通过避免峰值削波或严重压缩使低声级语音可听且高声级语音失真较小的输入-输出函数产生了更高的语音识别分数。这些结果与文献中先前的发现一致。
当助听器使用者不能或不想操作音量控制时，低压缩比区域扩展到高输入电平或具有高压缩限制阈值的WDRC在嘈杂环境中对语音识别最佳。需要对不同输入-输出函数的主观偏好进行进一步研究。
