School-age children's environmental object identification in natural auditory scenes: effects of masking and contextual congruence.
Krishnan S., Leech R., Aydelott J., Dick F.
This study investigated the development of children's skills in identifying ecologically relevant sound objects within naturalistic listening environments, using a non-linguistic analog of the classic 'cocktail-party' situation. Children aged 7-12.5 years completed a closed-set identification task in which brief, commonly encountered environmental sounds were presented at varying signal-to-noise ratios. To simulate the complexity of real-world acoustic environments, target sounds were embedded in either a single, stereophonically presented scene, or in one of two different scenes, with each scene presented to a single ear. Each target sound was either congruent or incongruent with the auditory context. Identification accuracy improved with increasing age, particularly in trials with low signal-to-noise ratios. Performance was most accurate when target sounds were incongruent with the background scene, and when sounds were presented in a single background scene. The presence of two backgrounds disproportionately disrupted children's performance relative to that of previously tested adults, and reduced children's sensitivity to contextual cues. Successful identification of familiar sounds in complex auditory contexts is the outcome of a protracted learning process, with children reaching adult levels of performance after a decade or more of experience.