Lorenzi C, Gatehouse S, Lever C
MRC Institute of Hearing Research (Scottish Section), Royal Glasgow Infirmary, Scotland, United Kingdom.
J Acoust Soc Am. 1999 Jun;105(6):3454-63. doi: 10.1121/1.424672.
The present study assesses the ability of four listeners with high-frequency, bilateral symmetrical sensorineural hearing loss to localize and detect a broadband click train in the frontal-horizontal plane, in quiet and in the presence of a white noise. The speaker array and stimuli are identical to those described by Lorenzi et al. (in press). The results show that: (1) localization performance is only slightly poorer in hearing-impaired listeners than in normal-hearing listeners when noise is at 0 deg azimuth, (2) localization performance begins to decrease at higher signal-to-noise ratios for hearing-impaired listeners than for normal-hearing listeners when noise is at +/- 90 deg azimuth, and (3) the performance of hearing-impaired listeners is less consistent when noise is at +/- 90 deg azimuth than at 0 deg azimuth. The effects of a high-frequency hearing loss were also studied by measuring the ability of normal-hearing listeners to localize the low-pass filtered version of the clicks. The data reproduce the effects of noise on three out of the four hearing-impaired listeners when noise is at 0 deg azimuth. They reproduce the effects of noise on only two out of the four hearing-impaired listeners when noise is at +/- 90 deg azimuth. The additional effects of a low-frequency hearing loss were investigated by attenuating the low-pass filtered clicks and the noise by 20 dB. The results show that attenuation does not strongly affect localization accuracy for normal-hearing listeners. Measurements of the clicks' detectability indicate that the hearing-impaired listeners who show the poorest localization accuracy also show the poorest ability to detect the clicks. The inaudibility of high frequencies, "distortions," and reduced detectability of the signal are assumed to have caused the poorer-than-normal localization accuracy for hearing-impaired listeners.
本研究评估了四名患有高频双侧对称性感音神经性听力损失的听众在安静环境以及存在白噪声的情况下，在额-水平面定位和检测宽带点击序列的能力。扬声器阵列和刺激与Lorenzi等人（即将发表）所描述的相同。结果表明：（1）当噪声位于0度方位角时，听力受损听众的定位表现仅比正常听力听众稍差；（2）当噪声位于±90度方位角时，听力受损听众在较高信噪比下的定位表现开始比正常听力听众下降；（3）当噪声位于±90度方位角时，听力受损听众的表现比在0度方位角时更不稳定。还通过测量正常听力听众定位点击声低通滤波版本的能力，研究了高频听力损失的影响。当噪声位于0度方位角时，数据重现了四名听力受损听众中三人受噪声影响的情况。当噪声位于±90度方位角时，数据仅重现了四名听力受损听众中两人受噪声影响的情况。通过将低通滤波后的点击声和噪声衰减20 dB，研究了低频听力损失的额外影响。结果表明，衰减对正常听力听众的定位准确性影响不大。点击声可检测性的测量表明，定位准确性最差的听力受损听众检测点击声的能力也最差。高频听不见、“失真”以及信号可检测性降低被认为是听力受损听众定位准确性低于正常水平的原因。
