Children's use of spatial and visual cues for release from perceptual masking

This study examined the role of visual speech in providing release from perceptual masking in children by comparing visual speech benefit across conditions with and without a spatial separation cue. Auditory-only and audiovisual speech recognition thresholds in a two-talker speech masker were obtained from 21 children with typical hearing (7-9 years of age) using a color-number identification task. The target was presented from a loudspeaker at 0° azimuth. Masker source location varied across conditions. In the spatially collocated condition, the masker was also presented from the loudspeaker at 0° azimuth. In the spatially separated condition, the masker was presented from the loudspeaker at 0° azimuth and a loudspeaker at -90° azimuth, with the signal from the -90° loudspeaker leading the signal from the 0° loudspeaker by 4 ms. The visual stimulus (static image or video of the target talker) was presented at 0° azimuth. Children achieved better thresholds when the spatial cue was provided and when the visual cue was provided. Visual and spatial cue benefit did not differ significantly depending on the presence of the other cue. Additional studies are needed to characterize how children's preferential use of visual and spatial cues varies depending on the strength of each cue.