Baker Richard J, Rosen Stuart
Human Communication and Deafness, School of Education, University Of Manchester, United Kingdom.
J Acoust Soc Am. 2002 Mar;111(3):1330-9. doi: 10.1121/1.1448516.
Sensorineural hearing loss has frequently been shown to result in a loss of frequency selectivity. Less is known about its effects on the level dependence of selectivity that is so prominent a feature of normal hearing. The aim of the present study is to characterize such changes in nonlinearity as manifested in the auditory filter shapes of listeners with mild/moderate hearing impairment. Notched-noise masked thresholds at 2 kHz were measured over a range of stimulus levels in hearing-impaired listeners with losses of 20-50 dB. Growth-of-masking functions for different notch widths are more parallel for hearing-impaired than for normal-hearing listeners, indicating a more linear filter. Level-dependent filter shapes estimated from the data show relatively little change in shape across level. The loss of nonlinearity is also evident in the input/output functions derived from the fitted filter shapes. Reductions in nonlinearity are clearly evident even in a listener with only 20-dB hearing loss.
感音神经性听力损失经常被证明会导致频率选择性丧失。对于它对选择性水平依赖性的影响了解较少，而这种水平依赖性是正常听力的一个显著特征。本研究的目的是描述轻度/中度听力受损听众的听觉滤波器形状所表现出的非线性变化。在20 - 50分贝听力损失的听力受损听众中，在一系列刺激水平下测量了2千赫处的带凹口噪声掩蔽阈值。与正常听力的听众相比，听力受损听众不同凹口宽度的掩蔽增长函数更平行，表明滤波器更线性。根据数据估计的水平依赖性滤波器形状在不同水平下形状变化相对较小。在从拟合滤波器形状导出的输入/输出函数中，非线性的丧失也很明显。即使在只有20分贝听力损失的听众中，非线性的降低也很明显。
