Are the perceptual and cognitive changes associated with expertise due to improvements in domain-general abilities orchanges to domain-specific representations? Elmer et al. (2014) measured how controls, language experts, and musicianscategorized perceptually ambiguous sounds (blends of speech and music) and concluded domain-general changes underlieexpertise. Acoustic and perceptual analyses of their stimuli suggested their stimulus creation methodology might havedistorted the results. An experiment replicated and extended their findings with revised stimuli. Results suggest thatexpertise leads instead to domain-specific changes in representational weighting or selective attention.