The effect of stimulus type and testing method on talker discrimination of school-age children.

Efficient talker discrimination (TD) improves speech understanding under multi-talker conditions. So far, TD of children has been assessed using various testing parameters, making it difficult to draw comparative conclusions. This study explored the effects of the stimulus type and variability on children's TD. Thirty-two children (7-10 years old) underwent eight TD assessments with fundamental frequency + formant changes using an adaptive procedure. Stimuli included consonant-vowel-consonant words or three-word sentences and were either fixed by run or by trial (changing throughout the run). Cognitive skills were also assessed. Thirty-one adults (18-35 years old) served as controls. The results showed (1) poorer TD for the fixed-by-trial than the fixed-by-run method, with both stimulus types for the adults but only with the words for the children; (2) poorer TD for the words than the sentences with the fixed-by-trial method only for the children; and (3) significant correlations between the children's age and TD. These results support a developmental trajectory in the use of perceptual anchoring for TD and in its reliance on comprehensive acoustic and linguistic information. The finding that the testing parameters may influence the top-down and bottom-up processing for TD should be considered when comparing data across studies or when planning new TD experiments.