Effects of background noise, talker’s voice, and speechreading on speech understanding by primary school children in simulated classroom listening situations

In the primary school classroom, children are exposed to multiple factors that combine to create adverse conditions for listening to and understanding what the teacher is saying. Four experiments were conducted to investigate the combined effects of background babble noise (quiet vs. noise), voice quality (normal vs. dysphonic), and speechreading (audio-only vs. audio-visual cues) on speech understanding in 245 eight-year old children. Comprehension was tested using narratives from the test of Clinical Evaluation of Language Fundamentals. Background babble noise was composed of several children talking. Visual speech cues were presented using a digitally animated talker. Vocal loading was used to induce a dysphonic (hoarse) voice. Speech understanding was reduced by even low levels of babble noise, but compensated by visual cues. Dysphonia did not significantly reduce comprehension scores, but it was considered unpleasant. There was some evidence that performance in adverse conditions was positively associated with individual differences in cognitive executive function. Overall, these results suggest that multiple factors combine to influence speech understanding and listening effort for child listeners in the primary school classroom. The constellation of these room, talker, modality, and listener factors should be taken into account in the planning and design of educational and learning activities.