Effects of a low-intensity two-talker speech masker on real-time spoken word recognition processes in children with normal hearing

To comprehend speech, listeners much efficiently initiate lexical access (i.e., recognize word form), activate semantics (i.e., recognize word meaning), and suppress lexical competition. This study used a Visual World Paradigm eye-tracking task to examine how the presence of a low-intensity two-talker speech masker may disrupt these real-time processes in 19 10- to 12-year-old children with normal hearing. Each child completed the task (1) in quiet and (2) with the masker presented at a level individually determined to ensure high accuracy (mean SNR = 4.5 dB). Although accuracy was high while listening with the masker (mean accuracy >95%), children showed slower lexical access and semantic activation, relative to listening in quiet. Speed of semantic activation in the masker condition was not predicted by lexical access speed, suggesting that delayed semantic activation while listening to masked speech is not simply the result of delayed lexical access; rather, the presence of a two-talker speech masker may disrupt children’s ability to process word meaning. Participants also showed increased and prolonged lexical competition when listening with the masker, suggesting that a low-intensity masker may reduce children’s ability to resolve competition and commit fully to the target word, even when they ultimately recognize the word accurately.