Effect of response context and masker type on word recognition in school-age children and adults

Abstract

In adults, masked speech recognition improves with the provision of a closed set of response alternatives. The present study evaluated whether school-age children (5-13 years) benefit to the same extent as adults from a forced-choice context, and whether this effect depends on masker type. Experiment 1 compared masked speech reception thresholds for disyllabic words in either an open-set or a four-alternative forced-choice (4AFC) task. Maskers were speech-shaped noise or two-talker speech. Experiment 2 compared masked speech reception thresholds for monosyllabic words in two 4AFC tasks, one in which the target and foils were phonetically similar and one in which they were dissimilar. Maskers were speech-shaped noise, amplitude-modulated noise, or two-talker speech. For both experiments, it was predicted that children would not benefit from the information provided by the 4AFC context to the same degree as adults, particularly when the masker was complex (two-talker) or when audible speech cues were temporally sparse (modulated-noise). Results indicate that young children do benefit from a 4AFC context to the same extent as adults in speech-shaped noise and amplitude-modulated noise, but the benefit of context increases with listener age for the two-talker speech masker.

FIG. 1.

The SRTs of individual child listeners are plotted as function of age. Adult means are shown at the right, with error bars indicating the 95% confidence interval. Symbol shading indicates the listener's task, which was either open set (open circles) or 4AFC (filled circles). Results for the speech-shaped noise masker are shown in the top panel, and those for the two-talker speech masker are shown in the bottom panel. Associations between SRT and child age are indicated with lines; solid lines indicate significant correlations, and dotted lines indicate non-significant trends.

FIG. 2.

The SRTs of individual child listeners are plotted as function of age. Adult means are shown at the right, with error bars indicating the 95% confidence interval. Symbol shading indicates the phonetic similarity between words in the 4AFC response set, which was either similar (open circles) or dissimilar (filled circles). Results for the three masker conditions are shown in separate panels; speech-shaped noise (top panel), two-talker speech (middle panel), and modulated noise (bottom panel). Associations between SRT and child age are indicated with lines; solid lines indicate significant correlations, and dotted lines indicate non-significant trends.

FIG. 3.

Modulation masking release, computed as the difference between SRTs in the speech-shaped noise and modulated noise conditions, is plotted as function of child listener age. Adult means are shown at the right of the panel, with error bars indicating the 95% confidence interval. Symbol fill indicates the phonetic similarity between words in the 4AFC response set, which was either similar (open circles) or dissimilar (filled circles).