The ERP effects of left-edge, sentence-medial boundary tones in East Swedish were examined using synthesized and nonsynthesized F0. The perception of the boundary tone gave rise to an N100 effect, reflecting automated processing of the acoustic features of the stimuli, a broadly distributed P200 effect, similar to what has earlier been seen for sentence-initial pitch accents, and an expectancy negativity, previously observed in response to sentence-medial, expected pitch accents. The N100 effect was clear only for the synthesized stimuli, possibly due to their relatively greater salience. The P200 was only seen in the combined results. The expectancy negativity was present in the combined results as well as for the non-edited stimuli. The F0 synthesis in the environment of voiceless obstruents produced a difference in the F0 level before the disambiguation point of the H boundary tone, which led to an anterior negativity starting around 50 ms before the H.