Specific loss of neural sensitivity to interaural time difference of unmodulated noise stimuli following noise-induced hearing loss.
Specific loss of neural sensitivity to interaural time difference of unmodulated noise stimuli following noise-induced hearing loss.
复制标题
噪声引起的听力损失后，神经对未调制噪声刺激的耳间时间差的敏感性发生特定损失。
DOI：
10.1152/jn.00349.2020
复制
发表时间：
2020
影响因子：
2.5
通讯作者：
Day,MitchellL
中科院分区：
文献类型：
--
作者：
Haragopal,Hariprakash;Dorkoski,Ryan;Pollard,AustinR;Whaley,GarethA;Wohl,TimothyR;Stroud,NoelleC;Day,MitchellL
感音神经性听力损失（SNHL）导致双耳听力的整体缺陷，包括定位声源，区分耳间时间和水平差异（分别为ITD和ILD）以及利用双耳线索来帮助在嘈杂环境中检测和理解信号的能力。很少有研究检查SNHL对中央听觉系统双耳编码的影响，以及那些专注于年龄相关听力损失的研究。我们通过噪声过度暴露诱导雄性和雌性荷兰带兔听力损失，并将其下丘[听力损失（HL）神经元]的未麻醉单单位反应与未暴露兔的单单位反应进行比较。HL神经元对噪声的声级阈值平均提高75 dB。HL神经元的放电率的宽带噪声刺激的方位角的敏感性降低，平均而言，但混淆组之间的检测阈值的声音水平的差异。我们独立操纵ITD和ILD在虚拟的声学空间，发现双耳敏感HL神经元的方向敏感性完全是由于ILD的敏感性，并没有不同的，为未暴露的兔子。然而，双耳敏感HL神经元的ITD敏感性是完全不存在的噪声刺激，无论是在虚拟的声学空间和ITD延伸到±3 ms。HL神经元也有较弱的尖峰定时精度和自发率略有增加。总体而言，ILD敏感性未受影响，而ITD敏感性完全丧失，这意味着严重SNHL后双耳之间的声学噪声波形的时序或相关性中无法使用特定信息。新&值得注意的是，感音神经性听力损失损害了双耳听觉产生的感知能力，但其对双耳神经反应方面的影响在很大程度上是未知的。我们发现，由于声创伤导致的严重听力损失，听觉中脑神经元特别失去了对两耳宽带噪声刺激到达之间的时间差进行编码的能力，而对两耳之间的声级差进行编码的能力仍然没有受到影响。
Sensorineural hearing loss (SNHL) causes an overall deficit in binaural hearing, including the abilities to localize sound sources, discriminate interaural time and level differences (ITDs and ILDs, respectively), and utilize binaural cues to aid signal detection and comprehension in noisy environments. Few studies have examined the effect of SNHL on binaural coding in the central auditory system, and those that have focused on age-related hearing loss. We induced hearing loss in male and female Dutch-belted rabbits via noise overexposure and compared unanesthetized single-unit responses of their inferior colliculi [hearing loss (HL) neurons] with those of unexposed rabbits. Sound-level thresholds of HL neurons to diotic noise were elevated by 75 dB, on average. Sensitivity of firing rates of HL neurons to the azimuth of a broadband noise stimulus was reduced, on average, but was confounded by differences in sound level with respect to detection threshold between groups. We independently manipulated ITD and ILD in virtual acoustic space and found directional sensitivity in binaurally sensitive HL neurons was entirely due to ILD sensitivity and no different than that for unexposed rabbits. However, ITD sensitivity was completely absent in binaurally sensitive HL neurons for noise stimuli both in virtual acoustic space and with ITDs extending to ±3 ms. HL neurons also had weaker spike-timing precision and slightly increased spontaneous rates. Overall, ILD sensitivity was uncompromised, whereas ITD sensitivity was completely lost, implying a specific inability to use information in the timing or correlation of acoustic noise waveforms between the two ears following severe SNHL.NEW & NOTEWORTHYSensorineural hearing loss compromises perceptual abilities that arise from hearing with two ears, yet its effects on binaural aspects of neural responses are largely unknown. We found that, following severe hearing loss because of acoustic trauma, auditory midbrain neurons specifically lost the ability to encode time differences between the arrival of a broadband noise stimulus to the two ears, whereas the encoding of sound level differences between the two ears remained uncompromised.