Auditory stream segregation using amplitude modulated bandpass noise.
Auditory stream segregation using amplitude modulated bandpass noise.
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DOI：
10.3389/fpsyg.2015.01151
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发表时间：
2015
影响因子：
3.8
通讯作者：
Nelson PB
中科院分区：
文献类型：
--
作者：
Nie Y;Nelson PB
本研究的目的是研究频谱重叠和调幅 (AM) 速率对于噪声信号流分离的作用，并测试基于这两个线索的累积效应。使用客观范例来评估隔离能力，并将听众的注意力集中在流隔离上。刺激序列由两组交错的带通噪声突发（A 和 B 突发）组成。 A 和 B 突发在频谱、AM 速率或两者上都有所不同。两组噪声突发之间的差异量是不同的。研究了长序列和短序列，以研究基于光谱和 AM 速率差异的分离的累积效应。结果表明：(1)．流分离能力随着光谱分离的增加而增加。 （2）。较大的 AM 速率分离与较强的分离能力相关。 （3）。研究发现，光谱分离会对当前研究中评估的光谱差异范围产生累积效应。 （4）。 AM 速率分离与光谱分离相互作用，表明光谱分离和 AM 速率分离对偏析的形成具有累加效应。研究结果表明，当听力正常的听众将注意力集中在分离上时，他们能够根据减少的频谱对比度线索来分离听觉流，这些线索因频谱重叠量而异。此外，无论光谱分离如何，他们都能够使用 AM 速率差异作为次要/较弱的线索。根据频谱差异，随着聆听持续时间的延长，听众可以更好地分离听觉流，即稀疏的频谱线索会引起分离；然而，AM 速率差异似乎仅在与频谱差异线索结合时才会引起累积。
The purpose of this study was to investigate the roles of spectral overlap and amplitude modulation (AM) rate for stream segregation for noise signals, as well as to test the build-up effect based on these two cues. Segregation ability was evaluated using an objective paradigm with listeners' attention focused on stream segregation. Stimulus sequences consisted of two interleaved sets of bandpass noise bursts (A and B bursts). The A and B bursts differed in spectrum, AM-rate, or both. The amount of the difference between the two sets of noise bursts was varied. Long and short sequences were studied to investigate the build-up effect for segregation based on spectral and AM-rate differences. Results showed the following: (1). Stream segregation ability increased with greater spectral separation. (2). Larger AM-rate separations were associated with stronger segregation abilities. (3). Spectral separation was found to elicit the build-up effect for the range of spectral differences assessed in the current study. (4). AM-rate separation interacted with spectral separation suggesting an additive effect of spectral separation and AM-rate separation on segregation build-up. The findings suggest that, when normal-hearing listeners direct their attention towards segregation, they are able to segregate auditory streams based on reduced spectral contrast cues that vary by the amount of spectral overlap. Further, regardless of the spectral separation they are able to use AM-rate difference as a secondary/weaker cue. Based on the spectral differences, listeners can segregate auditory streams better as the listening duration is prolonged—i.e., sparse spectral cues elicit build-up segregation; however, AM-rate differences only appear to elicit build-up when in combination with spectral difference cues.