Research on the causes and consequences of vocal accommodation is accumulating rapidly in social psychology, but important puzzles remain. Recent work has shown that patterns of vocal accommodation among actors engaged in competitive interactions (e.g., debates) are related to audience perceptions of their relative dominance but not prestige. This makes intuitive sense, but it remains unclear how audience perceptions of actors' relative dominance and/or prestige are impacted in cooperative group interactions and whether and to what extent audience perceptions agree with actors' own perceptions. Building on past theory and research on vocal accommodation, we address these methodological questions by analyzing data from two experimental studies. Results reveal that for cooperative interactions involving two actors, vocal accommodation is associated with actor and observer perceptions of dominance and prestige, but not to an equal extent. For actors, vocal accommodation is more strongly predictive of their perceptions of each other's relative prestige. For observers, vocal accommodation is more strongly predictive of their perceptions of actors' relative dominance. We offer an explanation for the difference and provide directions for future research.