Is conceptual priming for environmental sounds obligatory?

Conceptual priming for environmental sounds was examined in two tasks using pairs of a visually presented word (prime stimulus) and an environmental sound (probe stimulus). In the first task (physical task) participants had to indicate to which ear the sound was presented. In the second task (semantic task) participants judged whether word and sound of a pair fitted together. Participants switched between the two tasks randomly, with the color of the word indicating each trial which task was to be performed. An N400-effect for unrelated compared to related sounds was observed in both tasks, although reaction times did not reveal a statistically reliable priming effect. The results show that environmental sounds are processed conceptually even if the task does not require analysis of stimulus meaning.