McFadden S L, Willott J F
Department of Psychology, Northern Illinois University, DeKalb 60115.
Hear Res. 1994 Aug;78(2):132-48. doi: 10.1016/0378-5955(94)90019-1.
Extracellular recordings were obtained from inferior colliculus neurons of young adult (2-month-old) C57 mice with normal hearing and middle-aged (6-month-old) C57 mice with sensorineural hearing loss as they responded to best frequency (BF) tones (signal) in the presence of a continuous background noise (masker). Rate/level functions were obtained for the signal alone, noise bursts alone, and the signal in continuous noise as a function of masker location. For both groups of mice, thresholds for BF tones were significantly elevated in the presence of noise at all three noise locations. Separating the signal and masker sources significantly improved masked tone thresholds of 2-month-old mice but not hearing-impaired mice. The decreased ability of middle-aged mice to benefit from separation of the signal and masker sources may reflect alterations in binaural processing as a result of sensorineural hearing loss.
从听力正常的年轻成年（2个月大）C57小鼠和患有感音神经性听力损失的中年（6个月大）C57小鼠的下丘神经元进行细胞外记录，记录它们在连续背景噪声（掩蔽音）存在的情况下对最佳频率（BF）纯音（信号）的反应。分别获得单独信号、单独噪声突发以及连续噪声中信号的速率/声级函数，作为掩蔽音位置的函数。对于两组小鼠，在所有三个噪声位置存在噪声的情况下，BF纯音的阈值均显著升高。分离信号和掩蔽音源显著改善了2个月大小鼠的掩蔽纯音阈值，但对听力受损小鼠没有效果。中年小鼠从信号和掩蔽音源分离中获益能力的下降可能反映了感音神经性听力损失导致的双耳处理改变。
