Hemispheric processing of vocal emblem sounds.

Vocal emblems, such as shh and brr, are speech sounds that have linguistic and nonlinguistic features; thus, it is unclear how they are processed in the brain. Five adult dextral individuals with left-brain damage and moderate-severe Wernicke's aphasia, five adult dextral individuals with right-brain damage, and five Controls participated in two tasks: (1) matching vocal emblems to photographs ('picture task') and (2) matching vocal emblems to verbal translations ('phrase task'). Cross-group statistical analyses on items on which the Controls performed at ceiling revealed lower accuracy by the group with left-brain damage (than by Controls) on both tasks, and lower accuracy by the group with right-brain damage (than by Controls) on the picture task. Additionally, the group with left-brain damage performed significantly less accurately than the group with right-brain damage on the phrase task only. Findings suggest that comprehension of vocal emblems recruits more left- than right-hemisphere processing.