Recovery from prior stimulation: Masking of speech by interrupted noise for younger and older-adults with normal hearing
Recovery from prior stimulation: Masking of speech by interrupted noise for younger and older-adults with normal hearing
复制标题
DOI：
10.1121/1.1555611
复制
发表时间：
2003-04-01
影响因子：
2.4
通讯作者：
Ahlstrom, JB
中科院分区：
文献类型：
--
作者：
Dubno, JR;Horwitz, AR;Ahlstrom, JB
在先前的研究中[Dubno等人，J. Acoust.美国社会111，2897-2907（2002）]，老年受试者比年轻受试者更少地受益于在中断掩蔽者中听语音时信噪比的瞬时改善。已经假设从中断掩蔽中获得的益处可能与从前向掩蔽中恢复有关，即，从先前的掩蔽物刺激中恢复对阈上信号的反应。干扰掩蔽对语音识别的影响可能非常适合于测试关于从先前刺激中恢复的假设，因为两者都涉及掩蔽后信号的感知。在这里，听力图正常但不相同的年轻人和老年人在由2 Hz、10 Hz、25 Hz或50 Hz方波调制的语音形状噪声中以中等和高水平收听无意义音节。始终存在一个额外的低水平噪声，该噪声被成形为产生所有受试者的等效掩蔽阈值。为了评估从前向掩蔽的恢复，在0.5和4.0 kHz下测量前向掩蔽阈值，作为语音形状掩蔽物和信号之间的延迟的函数。在干扰噪声中，老年人的语音识别能力比年轻人差。小，但一致的年龄相关的差异，观察到在分数的减少与中断的噪音相对于分数没有中断的噪音。老年受试者的前向掩蔽阈值高于年轻受试者，但前向掩蔽量或同时掩蔽量无年龄相关差异。负相关的语音识别分数之间观察到中断噪声和正掩蔽阈值。也就是说，在中断的噪声中，语音可听度的瞬时改善所带来的好处随着前向掩蔽阈值的增加而减少。与前掩蔽的相关性较强，观察到较高的频率信号，较高的噪声中断率，当信噪比是穷人。年轻和年长受试者在中等和高水平的语音识别分数的比较与低自发率纤维对中断噪声中语音识别的贡献存在年龄相关差异的假设不一致。(C)2003年，美国声学学会。
In a previous study [Dubno et al., J. Acoust. Soc. Am. 111, 2897-2907 (2002)], older subjects benefitted less than younger subjects from momentary improvements in signal-to-noise ratio when listening to speech in interrupted maskers. It has been hypothesized that the benefit derived from interrupted maskers may be related to recovery from forward masking, i.e., the recovery of a response to a suprathreshold signal from prior stimulation by a masker. The effect of interrupted maskers on speech recognition may be well suited to test hypotheses regarding recovery from prior stimulation, given that both involve the perception of signals following a masker. Here, younger and older adults with normal but not identical audiograms listened to nonsense syllables at moderate and high levels in a speech-shaped noise that was modulated by a 2-, 10-, 25-, or 50-Hz square wave. An additional low-level noise was always present that was shaped to produce equivalent masked thresholds for all subjects. To assess recovery from forward masking, forward-masked thresholds were measured at 0.5 and 4.0 kHz as a function of the delay between the speech-shaped masker and the signal. Speech recognition in interrupted noise was poorer for older than younger subjects. Small but consistent age-related differences were observed in the decrease in score with interrupted noise relative to the score without interrupted noise. Forward-masked thresholds of older subjects were higher than those of younger subjects, but there were no age-related differences in the amount of forward masking or, in simultaneous masking. Negative correlations were observed between speech-recognition scores-in interrupted noise and forward-masked thresholds. That is, the benefit derived from momentary improvements in speech audibility in an interrupted noise decreased as forward-masked thresholds increased. Stronger correlations with forward masking were observed for the higher frequency signal, for higher noise interruption rates, and when the signal-to-noise ratio was poor. Comparisons of speech-recognition scores at moderate and high levels for younger and older subjects were not consistent with the hypothesis of an age-related difference in the contribution of low-spontaneous-rate fibers to speech recognition in interrupted noise. (C) 2003 Acoustical Society of America.