Allen P, Jones R, Slaney P
School of Communication Sciences and Disorders, University of Western Ontario, London, Canada.
J Acoust Soc Am. 1998 Nov;104(5):2997-3005. doi: 10.1121/1.423882.
Preschool-aged children and adults were asked to detect masked signals in four conditions that evaluated the role of level, spectral, and temporal cues on performance. Psychometric functions fitted to percent correct data at several signal-to-noise ratios showed higher thresholds and shallower slopes for the children in all conditions. Performance was similar in fixed and roving level conditions for both age groups suggesting use of level-invariant cues. When the signal was moved to the spectral edge of the masker the performance of the adults improved but that of the children did not. This suggested that children did not benefit from the additional cues provided by the off-center signal. Children's performance worsened when the signal was a narrow-band noise rather than a pure tone but the adults' did not, suggesting children's reliance on temporal changes in the masker with the introduction of the signal. Analyses of the stimuli suggested that the children's thresholds corresponded to signal-to-noise ratios at which multiple cues were present at magnitudes that were great enough to be discriminable.
研究人员要求学龄前儿童和成年人在四种条件下检测被掩蔽的信号，这些条件评估了强度、频谱和时间线索对表现的作用。将心理测量函数拟合到几个信噪比下的正确百分比数据后发现，在所有条件下儿童的阈值都更高，斜率更平缓。两个年龄组在固定强度和变化强度条件下的表现相似，这表明他们使用了与强度无关的线索。当信号移至掩蔽音的频谱边缘时，成年人的表现有所改善，但儿童的表现没有变化。这表明儿童没有从偏离中心的信号所提供的额外线索中受益。当信号是窄带噪声而非纯音时，儿童的表现变差，而成年人则没有，这表明随着信号的引入，儿童依赖于掩蔽音中的时间变化。对刺激的分析表明，儿童的阈值对应的信噪比下，存在多种足以被区分的线索。
