Hemispheric asymmetry in the perception of emotional sounds.

Three experiments were conducted to investigate hemispheric asymmetry for the perception of emotional sounds. Pairs of human nonspeech sounds were presented dichotically in a forced choice recognition task. Under divided attention conditions (Experiments 1 and 2) an left ear advantage (LEA) emerged during the second block of trials. Performance accuracy for the left and right ears was equal during the first block of trials. Under selective attention conditions (Experiment 3) an LEA emerged during the first block of trials. The results suggest that attention influences the rate of development of the laterality effect but not the direction of the effect.