In previous research evidence for the effects of stress and accent on phonetic variation is based on laboratory speech. In the present paper, we report on a study of the effects of accent on the acoustic cues for stop voicing and place of articulation in the speech of four announcers from the Boston University Radio News corpus. The results show that there are significant effects of accent on VOT, F0 and Closure Duration for voicing contrasts and significant effects on VOT and Closure Duration for place contrasts. In addition, comparison of the patterns of accentual effects reveals that the effect on voicing cues has a pattern of paradigmatic strengthening and combined strengthening, resulting in enhancement of voicing contrasts while syntagmatic strengthening appears to be the main effect on acoustic cues for place of articulation.